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Study Sessionto \ 1 OF GASO .111, s COUNCIL AGENDA REPORT �g DATE: JULY 29, 2013 TO: MAYOR AND TOWN COUNCIL FROM: GREG LARSON, TOWN MANAGER MEETING DATE: 8/5/13 STUDY SESSION .A�P- '�' SUBJECT: COUNCIL DISCUSSION ON THE REGULATION OF LEAF BLOWERS RECOMMENDATION: Provide direction on possible next steps regarding the regulation of leaf blowers. BACKGROUND: In July 2012, the Town of Los Gatos adopted a sustainability plan that outlined the Town's existing greenhouse gas emissions inventory, identified GHG reduction targets, and established GHG reduction measures to be implemented in order to meet those reduction targets. The possible adoption of a leaf blower ordinance (RE -4) was identified under Renewable Energy and Low Carbon Fuels. The purpose of this report is to provide the Council with information that reviews the environmental and health concerns related to the operation of leaf blowers; to provide a survey of actions taken by jurisdictions within Santa Clara County regarding leaf blower use; to identify potential impacts that could arise if a leaf blower ban or restrictions were introduced; and to provide options for leaf blower regulation. DISCUSSION: Environmental Concerns The three most common complaints of those who are opposed to the use and operation of leaf blowers are the health impacts from noise, air pollution and dust. While these complaints and concerns are valid, research and /or data that document the effects of leaf blower use on the environment and its health impacts are limited. PREPARED BY: Christina Gilmore, Assistant to the Town Manager Reviewed by: t Town Manager IN—Town Attorney Finance N: \ti1GRWdmiiiWorkFiles\2013 Council Reports\Aug 5 \8.5.13 Lear Blowers Study Session.doex PAGE 2 MAYOR AND TOWN COUNCIL SUBJECT: LEAF BLOWERS JULY 29, 2013 To inform the Council on these common complaints, staff has referenced information and data pulled from two sources: a report submitted by the California Air Resources Board (GARB) to the California State Legislature, "A Report to the California Legislature on the Potential Health and Environmental Impacts of Leaf Blowers," issued in February 2000 (Attachment 1), and a research study, completed by the Center for Environmental Research and Technology at the University of California, Riverside in January 2006 (Attachment 2), that performed measurements and data analysis to determine particulate matter emissions from leaf blowers. According to the report issued by the California Air Resource Board to the California State Legislature on February 29, 2000, leaf blowers were invented in the early 1970's and introduced shortly thereafter to the United States as a lawn and garden maintenance tool. As soon as leaf blowers were made available as a gardening and maintenance tool, two cities in California, Carmel -by- the -Sea and Beverly Hills, banned their use by adopting ordinances that identified the tool as a noise nuisance. Since the mid - 1970's, numerous cities in California have adopted restrictions on leaf blower use, targeting gasoline powered equipment and restricting its use within residential neighborhoods. Potential Health Impacts The CARB report identifies exhaust emissions, dust emissions, and noise as the three identifiable hazards resulting from prolonged exposure to leaf blower use. The report states the health effect from these hazards "as being generated by leaf blowers range from mild to serious, but the appearance of those effects depends on the exposures: the dose, or how much the hazard is received by a person, and the exposure time" (CARB, 2000, p. 4). Because estimates of exposure times were not available at the time that the report was written, the CARB concluded that they could not "conclusively determine the health impacts from leaf blowers; the discussion herein is clearly about potential health impacts" (GARB, 2000, p.4). The report also concludes that "leaf blower operators may be exposed to potentially hazardous concentrations of carbon monoxide (CO) and particulate matter (PM) intermittently throughout their work day, and noise exposure may be high enough that operators are at increased risk of developing hearing loss" (CARB, 2000, p. 4). However, "potential noise and PM health impacts should be reduced by the use of appropriate breathing and hearing equipment" (CARB, 2000, p. 4). Noise Significant improvement has been made by manufacturers in recent years to introduce quieter leaf blowers to the market that are rated at 65 decibels (dBA) or lower. Blowers that are rated at 65 decibels are significantly quieter than other blowers on the market that have ratings between 70 -90 decibels. 65 decibels is equivalent to a normal conversation at 3 feet. Particulate Matter A research study was completed by the Center for Environmental Research and Technology at the University of California, Riverside, 'and presented on January 2006 to the San Joaquin Valley Unified Air Pollution Control District, "Particulate Matter Emissions Factors and Emissions Inventory from Leaf Blowers in Use in the San Joaquin Valley." The purpose of the study was to "design a study and perform measurements and data analysis to determine the particulate matter emissions from leaf blowers PAGE 3 MAYOR AND TOWN COUNCIL SUBJECT: LEAF BLOWERS JULY 29, 2013 and to obtain a PM emission inventory from their operation in the District" (Fitz, 2006, p.1). Varieties of leaf blowers, including vacuums, rakes and brooms were used and evaluated during the course of this study. In a summary of emissions factors emitted per square meter of surface cleaned, the study observed the following: "there was little difference between blowing and vacuuming with the model that was tested; sweeping with a broom on concrete created significant PM whereas sweeping asphalt did not; and raking leaves did not generate significant amounts of PM" (Fitz, 2006, p. 2). Carbon Emissions The Air Resources Board (ARB) has implemented Tier I1 regulations to control emissions from small off -road engines such as lawn, garden and other maintenance utility equipment. The regulations cut total emissions of hydrocarbons (HC) and oxides of nitrogen (NOx) by 74 percent for handheld equipment. The current emissions standards for HC +NOx for gasoline powered handheld equipment are 50 g /kWH for products <50 cc (cubic centimeters) and 72 g /kWH for products >50ce. Based on this regulation, there are several manufacturers, such as Stihl, Husgvarna, Fuji, Honda and Kawasaki, whose lawn and garden utility equipment, specifically leaf blowers, meet these standards with relatively low - polluting, two and four - stroke engines. Bay Area Air Quality 1Llanagement District -Spare the Air Days The Spare the Air program was established by the Bay Area Air Quality Management District ( BAAQMD) in 1991 to reduce air pollution and provide advance notice when a "Spare the Air Alert" is in effect. BAAQMD declares Spare the Air Alerts on days when air quality is forecast to be unhealthy. The Spare the Air program has two seasonal components that educate residents about the effects of air pollution and encourages them to take action to improve air quality in the Bay Area. During the summer months, the Spare the Air program notifies residents when air quality is forecast to be unhealthy, and urges residents to drive less and reduce activities that contribute to smog. The Winter Spare the Air program notifies residents when soot levels are anticipated to be high. When unhealthy air is forecast, BAAQMD will issue a Winter Spare the Air Alert which prohibits burning wood, firelogs or pellets in fireplaces, woodstoves, or outdoor fire pits. BAAQI\/ID provides a list of actions that residents can take to help reduce air pollution, especially in the summer. The actions recommended with the most impact are to drive less, utilize public transit or carpool whenever possible. Additional actions that residents can do at home include using an electric or old fashioned push lawn mower, using a broom instead of leaf blower, using a gas grill instead of charcoal, and turning off lights and appliances that are not in use. Leaf Blotiver Exchange Program The South Coast Air Quality Management District (AQMD) has been funding a leaf blower exchange program in the South Coast Air Basin since 2006. The goal of this program is to replace existing gas powered back pack blowers with blowers that emit reduced emissions and noise levels. Currently, four counties, Orange, Los Angeles, San Bernardino and Riverside counties participate in the program, and to date, a total of 7,500 gas powered leaf blowers have been exchanged. PAGE 4 MAYOR AND TOWN COUNCIL SUBJECT: LEAF BLOWERS JULY 29, 2013 The program focuses on exchanging blowers that meet the California Air Resources Board Blue Sky Emissions standards for leaf blowers that do not meet those standards. As mentioned previously, the current emissions standards for gasoline powered handheld equipment are 50 g/kWh for products <50cc (cubic centimeters) and 72 g/kWh for products >50 cc. For the last several years, the AQMD RFQ process has chosen the Stihl BR 500 leaf blower for the leaf blower exchange, as this devise is currently certified at 13 g /kWh, which is 115 "' of the level of current emissions standards and has a rating of 65 decibels. Leaf blower exchanges and community outreach are conducted exclusively by Stihl dealerships throughout the AQMD district area. During the exchange, old blowers are tested for operation, drained of all fluids and collected for scrapping. The vendor hauls the traded in blowers to a scrapping yard, where they are crushed and recycled, in addition to providing training for proper use of the new equipment. Annually, the program exchanges up to 1,500 old 2- stroke blowers for a new 4- stroke blower. The AQMD estimates that within their region, leaf blowers are used up to four hours per week and with the new blowers, achieves emissions reductions of 65,279 lbs. per year of HC +NOx. Program funding comes from the South Coast AQMD Rule 2202 Air Quality Investment Program Special Revenue Fund. The 2012 program costs were approximately $269,925 and funds the exchange of 1,500 blowers. The price for each Stihl blower is $469.95. AQMD receives an additional discount of $90 which brings the price down to $379.95 per piece of equipment. The customer pays $200 plus tax for each blower and the .AQMD share comes to $179.95 per blower. The event and advertising budget is an additional $55,000 each year. Staff has contacted BAAQMD to inquire about potential firture plans to implement a similar type of program within this region. Currently, BAAQMD does not have plans to implement such a program; however, they are considering launching a lawn mower exchange program sometime in the future. Leaf Blower Regulations in Santa Clara County The majority of cities within Santa Clara County allow the use of both gas - powered and electric blowers, but they are limited in their operation during specific hours and /or specific days of the week. Los Gatos restricts the use of electric or gasoline lawn mowers, leaf blowers, edge trimmers, hedge trimmers and other similar moveable noise sources to the hours of 8:00 a.m. to 8:00 p.m. weekdays, and 9:00 a.m. to 7 :00 p.m. on weekends and holidays in residential or other noise sensitive zones. The use of powered equipment in commercial, industrial or public spaces is not time limited. Currently, the City of Palo Alto and the City of Los Altos are the only two cities in Santa Clara County to have bans on gas powered blowers. Both cities allow electric blowers to be used as an alternative. Enforcement of the blower ordinance is similar in both cities. Citizens who observe a violation in Palo Alto can call the Police Department on a non - emergency number to provide information and answer questions about their observances. Anonymous complaints are not investigated, and leaf blower complaints /violations are classified at the lowest priority and have a minimum response time of one hour. If an officer observes a violation in progress, the officer can administer a citation at their discretion. PAGE 5 MAYOR AND TOWN COUNCIL SUBJECT: LEAF BLOWERS JULY 29, 2013 In Los Altos, citizens can mail in information about potential violators to the Police Department. A warning letter is sent to the address where the violation took place for compliance. After two warning letters are mailed, the Los Altos Municipal Code is used, if needed for compliance. Failure to comply may result in citations issued and a mandatory appearance before a hearing officer, with the possibility of additional fees and civil penalties imposed. Attachment 3 provides a matrix of Santa Clara County cities regulations on leaf blowers. Issues for Consideration As previously discussed, the potential advantages of leaf blower bans or restriction include: • Reduced mobile sources of noise • Reduced gasoline fuel emissions • Reduced airborne particulate matter • Possible health benefits to leaf blower operators if appropriate breathing and hearing protection are used. Due to the limited data regarding the enviromnental impact of leaf blowers, definitive environmental and health impacts are not known, thus raising questions about the need and justification for bans or other regulations. Below, are a few issues for consideration if a ban were to be put into effect. Opposition from Homeowners and Landscape & Gardening Professionals Many homeowners use leaf blowers for landscape and property maintenance in addition to employing landscapers and gardening professionals who utilize leaf blowers as part of their daily operations. Homeowners who use leaf blowers may object to any potential ban or restriction on the use of leaf blowers that prevents their ability to maintain their property. Similarly, landscape and gardening professionals may feel prohibited in their ability to complete jobs in an efficient and timely manner, and could potentially pass on increased labor costs to complete jobs without the use of a blower to their residential and commercial customers. Financial Impacts to Town Operations Any potential ban or restrictions on the use of leaf blowers within the Town of Los Gatos would have a substantial impact on Parks and Public Works (PPW) operations. Currently, PPW staff use leaf blowers for parks and civic grounds maintenance, as well as Town contractors who use leaf blowers for'median maintenance and turf maintenance (edging). The level of cleanliness for which Town parks and civic grounds are maintained would be affected, in addition to the potential financial impacts on staffing, if a ban or restriction on leaf blower resulted in staff performing any of the work manually. Additional analysis would need to be conducted by PPW to determine the actual fiscal and operational impacts. Enforcement Proactive enforcement of a blower ban would also incur additional costs and staff time to respond to any property owner deemed out of compliance. Cities who have enacted blower bans have found them difficult to enforce, often due to lack of resources available to conduct enforcement. Additional analysis PAGE 6 MAYOR AND TOWN COUNCIL SUBJECT: LEAF BLOWERS JULY 29, 2013 would need to be conducted by the Town Manager's office to determine the actual costs of enforcement, the staff time involved, as well as to determine the correct department that would be responsible for enforcement. CONCLUSION: Staff seeks direction from the Council on the possible next steps regarding the regulation of leaf blowers. Potential options for the Council to discuss include: 1. Make no changes in the current ordinance that prescribes the hours and days of use of electric and gas powered lawn equipment in residential and commercial areas; 2. Amend the current ordinance to reduce the hours and days of operation of use of electric and gas powered lawn equipment in residential and commercial areas; 3. Prohibit the use of electric or gas powered leaf blowers that emit 65 decibels or more in residential and commercial areas; 4. Prohibit the use of only gas powered leaf blowers in residential and commercial areas; 5. Adopt a policy, similar to the BAAQMD Spare the Air policy, which educates residential and commercial property owners to utilize alternative methods for lawn and garden maintenance during low air quality days; and /or 6. Pursue options for a leaf blower exchange program, similar to the one implemented by the AQMD, in partnership with the BAAQMD. ENVIRONMENTAL ASSESSMENT: Is not a project defined under CEQA, and no fiirther action is required. FISCAL IMPACT: The fiscal impact will differ depending on the direction given by the Council. Attachments: 1. California Environmental Protection Agency, Air Resources Board, Mobile Source Control Division, (2000) A Report to the California Legislature on the Potential Health and Environmental Impacts of Leaf Blotivers 2. Fitz, D.R., Pankratz, D., Chitjian, M., Bristow, J., & Pederson, S., Center for Environmental Research and Technology, University of California Riverside (2006) Particulate IYlatter Emissions Factors and Emissions Inventory from Leaf Blotivers in' Use in the San Joaquin Valley 3. Matrix of Santa Clara County Leaf Blower Restrictions California Environmental Protection Agency B= AIR RESOURCES BOARD A REPORT TO THE CALIFORNIA LEGISLATURE ON THE POTENTIAL HEALTH AND ENVIRONMENTAL IMPACTS OF LEAF BLOWERS Mobile Source Control Division February 2000 State of California ATTACHMENT 1 AIR RESOURCES BOARD A REPORT TO THE CALIFORNIA LEGISLATURE ON THE POTENTIAL HEALTH AND ENVIRONMENTAL IMPACTS OF LEAF BLOWERS Public Hearing: January 27, 2000 Date of Revision: February 29, 2000 This report has been reviewed by the staff of the California Air Resources Board and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the Air Resources Board, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. I_[91 N ILSIVII I-41 sr]►yil?1ki1 V This report on potential health and environmental impacts of leaf blowers was developed by the following Air Resources Board staff: Mobile Sources Control Division: Nancy L.C. Steele, D.Env. (Lead) Scott Rowland Michael Carter (Branch Chief) Research Division: Hector Maldonado Cindy Stover And with the assistance of additional staff: Cresencia Gapas- Jackson, Leslie Krinsk, Jeff Long, Keith Macias, Angela Ortega, Muriel Strand, John Swanton, Maggie Wilkinson, and Walter Wong. The many other individuals who provided information and assistance for this report are listed in Appendix B. TABLE OF CONTENTS EXECUTIVESUMMARY .............................................................. ............................... 1 I. INTRODUCTION ................................................................ ............................... 7 A. Background .............................................................. ............................... 7 B History of the Leaf Blower and Local Ordinances ...... ............................... 7 C. Environmental Concerns ........................................... ............................... 8 D. Health and Environmental Impacts ................ ............................... . ........... 9 1. Life -cycle Impact Assessment ............................... ............................... 9 2. Risk Assessment ................................................. ............................... 10 E Public Involvement .................................................. ............................... 10 F. Overview of This Report ......................................... ............................... 11 II. DESCRIPTION OF THE HAZARDS ................................ ............................... 12 A. Exhaust Emissions ................................................... ............................... 12 1. Characterization of Technology ........................... ............................... 12 2. Exhaust Emissions .............................................. ............................... 13 a. Leaf Blower Population .......................... ............................... 13 b. Emission Inventory ................................. ............................... 14 3. Regulating Exhaust Emissions ............................ ............................... 14 a. State Regulations .................................... ............................... 14 b. Federal Regulations ................................ ............................... 15 c. South Coast AQMD Emissions Credit Program ..................... 16 4. Summary ............................................................ ............................... 16 B. Fugitive Dust Emissions .......................................... ............................... 16 1. Definition of Fugitive Dust Emissions ................. ............................... 17 2. Calculating Leaf Blower Emissions ..................... ............................... 18 a. Generation of Fugitive Dust by Leaf Blowers ......................... 18 b. Size Segregation of Particulate Matter .... ............................... 19 c. Calculation Assumptions and Limitations ............................... 19 d. Calculation Methodology ........................ ............................... 20 3. Characterization of Fugitive Dust Emissions ....... ............................... 21 a. Emission Factors - This Study ................. ............................... 21 b. Statewide Emissions Inventory - This Study .......................... 22 c. Previous Emissions Estimates: ARB, 1991 ............................. 23 d. Previous Emissions Estimates: SMAQMD ............................. 23 e. Previous Emissions Estimates: AeroVironment ...................... 23 4. Particulate Composition ..................................... ............................... 24 5. Regulating Fugitive Dust Emissions .................... ............................... 24 a. State and Federal PM10 and PM2,5 Standards ....................... 25 b. Local District Regulations ....................... ............................... 25 6. Summary .............................................................. .............................25 n C. Noise Emissions ...................................................... ............................... 26 1. Defining Noise ................................................... ............................... 26 2. Measuring the Loudness of Sound ...................... ............................... 27 a. Loudness Description .............................. ............................... 27 b. Sound Level Measurement ...................... ............................... 29 3. Noise in California .............................................. ............................... 30 a. Noise Sources ......................................... ............................... 30 b. Numbers of People Potentially Exposed: the Public ................ 30 c. Numbers of People Potentially Exposed: the Operator ........... 31 4. Regulating Noise ................................................ ............................... 31 a. Federal Law ............................................ ............................... 31 b. State Law ............................................... ............................... 31 c. Local Ordinances .................................... ............................... 32 5. Noise From Leaf Blowers ................................... ............................... 33 a. Bystander Noise Exposure ............ ................. ......_........................ 33 b. Operator Noise Exposure ........................ ............................... 34 6. Use of Hearing Protectors and Other Personal Protection Gear ......... 37 a. Zero Air Pollution Study ( 1999) .............. ............................... 38 b. Citizens for a Quieter Sacramento Study (1999b) ................... 38 c. Survey99 Report (Wolfberg 1999) .......... ............................... 38 7. Sound Quality .................................................... ............................... 39 8. Summary .............................................................. .............................41 III. REVIEW OF HEALTH EFFECTS ..................................... ............................... 42 A. Particulate Matter .................................................... ............................... 42 B. Carbon Monoxide ................................................... ............................... 43 C. Unburned Fuel ........................................................ ............................... 43 D. Ozone ..................................................................... ............................... 44 E. Noise ...................................................................... ............................... 44 1. Hearing and the Ear ............................................ ............................... 45 2. Noise - Induced Hearing Loss .............................. ............................... 45 3. Non - Auditory Physiological Response ................ ............................... 46 4. Interference with Communication ...................................................... 47 5. Interference with Sleep ....................................... .......................... ...... 47 6. Effects on Performance and Behavior ................. ............................... 47 7. Annoyance and Conununity Response ................ ............................... 48 8. Effects of Noise on Anunals ............................... ............................... 49 IV. POTENTIAL HEALTH AND ENVIRONMENTAL IMPACTS OF LEAF BLOWERS ..... 50 A. The Leaf Blower Operator ...................................... ............................... 50 1. Exhaust Emissions .............................................. ............................... 51 2. Fugitive Dust Emissions ..................................... ............................... 52 3. Noise ................................................................. ............................... 53 B. The Public -at -Large ................................................ ............................... 53 in 1. Exhaust Emissions .............................................. ............................... 54 2. Fugitive Dust Emissions ..................................... ............................... 55 3. Noise ................................................................. ............................... 55 C. Summary of Potential Health Impacts ...................... ............................... 56 V. RECOMMENDATIONS ...................................................... .............................58 VI. REFERENCES CITED ...................................................... ............................... 59 APPENDICES Appendix A SCR 19 Appendix B Contact List Appendix C Ambient Air Quality Standards Appendix D Chemical Speciation Profile for Paved Road Dust Appendix E Physical Properties of Sound and Loudness Measures Appendix F American National Standard For Power Tools - Hand -held and Backpack, Gasoline - Engine- Powered Blowers B175.2 -1996 Appendix G Manufacturer - reported Noise Levels from Leaf Blowers Appendix H Research Needs Appendix I Future .Technology and Alternatives Appendix J Exposure Scenarios for Leaf Blower Emissions and Usage Appendix K Bibliography List of Tables Table 1. Major findings of the Orange County Grand Jury and City of Palo Alto .............. 8 Table 2. Statewide inventory of leaf blower exhaust emissions ........ ............................... 14 Table 3. Exhaust emissions, per engine, for leaf blowers ................. ............................... 15 Table 4. Silt loading values, Riverside County ................................ ............................... 21 Table 5. Leaf blower estimated emission factors, this study ............. ............................... 22 Table 6. Leaf blower emissions, possible statewide inventory values, this study .............. 22 Table 7. Leaf blower operator noise exposures and duration of use . ............................... 36 Table 8. Sound levels of some leaf blowers ..................................... ............................... 37 Table 9. Commercial leaf blower emissions compared to light duty vehicle emissions..... 51 Table IO.Homeowner leaf blower emissions compared to light duty vehicle emissions ... 54 List of Figures Figure 1. Comparison of sound levels in the environment ....... ............................... 28 Figure 2. Loudness levels of leaf blowers (50 ft) ................................ I ......... I......... 34 Figure 3. Sound quality spectrum of a representative leaf blower ........................... 40 Figure 4. Sound quality spectrum of a representative neighborhood ....................... 40 IV EXECUTIVE SUMMARY Background and Overview California Senate Concurrent Resolution No. 19 (SCR 19) requests the Air Resources Board (ARB) to prepare and submit a report to the Legislature on or before January 1, 2000, summarizing the potential health and environmental impacts of leaf blowers and including recommendations for alternatives to the use of leaf blowers and alternative leaf blower technology, if the ARB determines that alternatives are necessary. The goal of this report is to summarize for the California Legislature existing data on health and environmental impacts of leaf blowers, to identify relevant questions not answered in the literature, and suggest areas for future research. The leaf blower was invented in the early 1970s and introduced to the United States_as_a lawn and garden maintenance tool. Drought conditions in California facilitated acceptance of the leaf blower as the use of water for many garden clean -up tasks was prohibited. By 1990, annual sales were over 800,000 nationwide, and the tool had become a ubiquitous gardening implement. In 1998, industry shipments of gasoline - powered: handheld and backpack leaf blowers increased 30% over 1997 shipments, to 1,868,160 units nationwide. Soon after the leaf blower was introduced into the U.S., its use was banned as a noise nuisance in two California cities, Carmel -by- the -Sea in 1975 and Beverly, Hills in 1978. By 1990, the number of California cities that had banned the use of leaf blowers was up to five. There are currently twenty California cities that have banned leaf blowers, sometimes only within residential neighborhoods and usually targeting gasoline - powered equipment. Another 80 cities have ordinances on the books restricting either usage or noise level or both. Other cities have considered and rejected leaf blower bans. Nationwide, two states, Arizona and New Jersey, have considered laws at the state level, and five other states have at least one city with a leaf blower ordinance. The issues usually mentioned by those who object to leaf blowers are health impacts from noise, air pollution, and dust. Municipalities regulate leaf blowers most often as public nuisances in response to citizen complaints. Two reports were located that address environmental concerns: the Orange County Grand Jury Report, and a series of reports from the City of Palo Alto City Manager's office. The City of Palo Alto reports were produced in order to make recommendations to the City Council on amending their existing ordinance. The Orange County Grand Jury took action to make recommendations to improve the quality of life in Orange County, and recommended that cities, school districts, community college districts, and the County stop using gasoline- powered leaf blowers in their maintenance and clean -up operations. The major findings of each are similar: leaf blowers produce exhaust emissions, resuspend dust, and generate high noise levels. As per SCR 19, this report includes a comprehensive review of existing studies of the impacts of leaf blowers on leaf blower operators and on the public at large, and of the availability and actual use of protective equipment for leaf blowers. The receptors identified by the resolution are humans and the environment; sources of impacts are exhaust, noise, and dust. Because the Legislature specified that ARB use existing information, staff conducted no new studies. In order to locate existing data, staff searched the published literature, contacted potential resources and experts, and requested data from the public via mail and through a web page devoted to the leaf blower report. Two public workshops were held in El Monte, California, to facilitate further discussions with interested parties. The methodology followed for this report depends on both the objectives of SCR 19 and available data. As staff discovered, in some areas, such as exhaust emissions, much is known; in other areas, such as fugitive dust emissions, we know very little. For both fugitive dust and noise, there are few or no data specifically on leaf blower impacts. For all hazards, there have been no dose - response studies related to emissions from leaf blowers, we do not know how many people are affected by those emissions, and no studies were located that address potential health impacts from leaf blowers. Therefore, staff determined to provide the Legislature with a report that has elements of both impact and risk assessments. The body of the report comprises three components, following the introduction: hazard identification, review of health effects, and a characterization of the potential impacts of leaf blowers on operators. and bystanders. In Section II, the emissions are quantified as to specific hazardous constituents, the number of people potentially exposed to emissions is discussed, and laws that seek to control emissions are summarized. Section III reviews health effects, identifying the range of potential negative health outcomes of exposure to the identified hazards. Section IV is a synthesis of hazard identification and health effects, characterizing potential health impacts that may be experienced by those exposed to the exhaust emissions, fugitive dust, and noise from leaf blowers in both occupational and non- occupational setting. Section V discusses recommendations. Additional information, including a discussion of research needs to make progress toward answering some of the questions raised by this report, a description of engine technologies that could reduce exhaust emissions and alternatives to leaf blowers, and a complete bibliography of materials received and consulted but not cited in the report, is found in the appendices. Description of the Hazards Hazard identification is the first step in an impact or risk assessment. Each of the three identified hazards are examined in turn, exhaust emissions, dust emissions, and noise. For each, the hazard is described and quantified, to the extent possible, and the number of people potentially exposed to the hazard is discussed. For exhaust emissions, the number of people potentially impacted is as high as the population of the state, differing within air basins. Fugitive dust emissions impact a varying number of people, depending on one's proximity to the source, the size of the particles, and the amount of time since the source resuspended the particles. Finally, we also discuss laws that control the particular hazard. 2 Exhaust emissions from leaf blowers consist of the following specific pollutants of concern: hydrocarbons from both burned and unburned fael, and which combine with other gases in the atmosphere to form ozone; carbon monoxide; fine particulate matter; and other toxic air contaminants in the unburned fuel, including benzene, 1,3- butadiene, acetaldehyde, and formaldehyde. Exhaust emissions from these engines, while high compared to on -road mobile sources on a per engine basis, are a small part of the overall emission inventory. Emissions have only been controlled since 1995, with more stringent standards taking effect in 2000. The exhaust emissions from leaf blowers are consistent with the exhaust emissions of other, similar off -road equipment powered by small, two- stroke engines, such as string trimmers. Manufacturers have developed several different methods to comply with the standards and have done an acceptable job certifying and producing engines that are below the regulated limits. Electric- powered models that are exhaust -free are also available. Data on fugitive dust indicate that the PM10 emissions impacts from dust suspended by leaf blowers are small, but probably significant. Previous emission estimates range from less than 1% to 5% of the statewide PM10 inventory. The ARB previously estimated statewide fugitive dust emissions to be about 5 percent of the total, the Sacramento Metropolitan AQMD estimated leaf blower fugitive dust emissions to be about 2 percent of the Sacramento county PM10 air burden, and AeroVironment estimated dust attributable to leaf blowers in the South Coast Air Basin to be less than 1% of all fugitive dust sources. Dust emissions attributable to leaf blowers are not part of the inventory of fugitive dust sources. ARB, therefore, does not have official data on the quantity of fugitive dust resuspended by leaf blowers. A more definitive estimate of leaf blower fugitive dust emissions will require verification of appropriate calculation parameters and representative silt loadings, measurement of actual fugitive dust emissions through source testing, and identification of the composition of leaf blower - generated fugitive dust. Noise is the general term for any loud, unmusical, disagreeable, or unwanted sound, which has the potential of causing hearing loss and other adverse health impacts. While millions of Californians are likely exposed to noise from leaf blowers as bystanders, given the ubiquity of their use and the increasing density of California cities and towns, there is presently no way of knowing for certain how many are actually exposed, because of the lack of studies. In contrast, it is likely that at least 60,000 lawn and garden workers are daily exposed to the noise from leaf blowers. Many gardeners and landscapers in southern California are aware that noise is an issue and apparently would prefer quieter leaf blowers. Purchases of quieter leaf blowers, based on manufacturer data, are increasing. While little data exist on the noise dose received on an 8 -hr time- weighted - average by operators of leaf blowers, data indicate that some operators may be exposed above the OSHA permissible exposure limit. It is unlikely that more than 10% of leaf blower operators and members of the gardening crew, and probably a much lower percentage, regularly wear hearing protection, thus exposing them to an increased risk of hearing loss. The sound quality of gasoline- powered leaf blowers may account for the high level of annoyance reported by bystanders. Review of Health Effects Potential health effects from exhaust emissions, fugitive dust, and noise range from mild to serious. Fugitive dust is not a single pollutant, but rather is a mixture of many subclasses of pollutants, each containing many different chemical species. Many epidemiological studies have shown statistically significant associations of ambient particulate matter levels with a variety of negative health endpoints, including mortality, hospital admissions, respiratory symptoms and illness, and changes in lung function. Carbon monoxide is a component of exhaust emissions which causes health effects ranging fi-om subtle changes to death. At low exposures, CO causes headaches, dizziness, weakness, and nausea..Children and people with heart disease are particularly at risk from CO exposure. Some toxic compounds in gasoline exhaust, in particular benzene, 1,3- butadiene, acetaldehyde, and formaldehyde, are carcinogens. Ozone, formed in the presence of sunlight from chemical reactions of exhaust emissions, primarily hydrocarbons and nitrogen dioxide, is a strong irritant and exposures can cause airway constriction, coughing, sore throat, and shortness of breath. Finally, noise exposures can damage hearing, and cause other adverse health impacts, including interference with communication, rest and sleep disturbance, changes in performance and behavior, annoyance, and other psychological and physiological changes that may lead to poor health. Potential Health and Environmental Impacts of Leaf Blowers Health effects from hazards identified as being generated by leaf blowers range from mild to serious, but the appearance of those effects depends on exposures: the dose, or how much of the hazard is received by a person, and the exposure time. Without reasonable estimates of exposures, ARB cannot conclusively determine the health impacts from leaf blowers; the discussion herein clearly is about potential health impacts. The goal is to direct the discussion and raise questions about the nature of potential health impacts for those exposed to the exhaust emissions, fugitive dust, and noise from leaf blowers in both occupational and non - occupational settings. For the worker, the analysis suggests concern. Bearing in mind that the worker population is most likely young and healthy, and-that these workers may not work in this business for all of their working lives, we nonetheless are cautioned by our research. Leaf blower operators may be exposed to potentially hazardous concentrations of CO and PM intermittently throughout their work day, and noise exposures may be high enough that operators are at increased risk of developing hearing loss. While exposures to CO, PM, and noise may not have immediate, acute effects, the potential health impacts are greater for long term exposures leading to chronic effects. In addition, evidence of significantly elevated concentrations of benzene and 1,3- butadiene in the breathing zone of operators leads to concern about exposures to these toxic air contaminants. Potential noise and PM health impacts should be reduced by the use of appropriate breathing and hearing protective equipment. Employers should be more vigilant in requiring and ensuring their employees wear breathing and hearing protection. Regulatory agencies should conduct educational and enforcement campaigns, in addition to exploring the extent of the use of protective gear. Exposures to CO and other air toxics are more problematic because there is no effective air filter. More study of CO and other air toxics exposures experienced by leaf blower M operators is warranted to determine whether the potential health effects discussed herein are actual effects or not. Describing the impacts on the public at large is more difficult than for workers because people's exposures and reactions to those exposures are much more variable. Bystanders are clearly annoyed and stressed by the noise and dust from leaf blowers. They can be interrupted, awakened, and may feel harassed, to the point of taking the time to contact public officials, complain, write letters and set up web sites, form associations, and attend city council meetings. These are actions taken by highly annoyed individuals who believe their health is being negatively impacted. In addition, some sensitive individuals may experience extreme physical reactions, mostly respiratory symptoms, from exposure to the kicked up dust. On the other hand, others voluntarily purchase and use leaf blowers in their own homes, seemingly immune to the effects that cause other people such problems. While these owner- operators are likely.not concerned about the noise and dust, they should still wear protective equipment, for example, eye protection, dust masks, and ear plugs, and their exposures to CO are a potential problem and warrant more study. Recommendations The Legislature asked ARB to include recommendations for alternatives in the report, if ARB determines alternatives are necessary. This report makes no recommendations for alternatives. Based on the lack of available data, such conclusions are premature at this time. Exhaust standards already in place have reduced exhaust emissions from the engines used on leaf blowers, and manufacturers have significantly reduced CO emissions further than required by the standards. Ultra -low or zero exhaust emitting leaf blowers could further reduce public and worker exposures. At the January 27, 2000, public hearing, the Air Resources Board directed staff to explore the potential for technological advancement in this area. For noise, the ARB has no Legislative mandate to control noise emissions, but the evidence seems clear that quieter leaf blowers would reduce worker exposures and protect hearing, and reduce negative impacts on bystanders. In connection with this report, the Air Resources Board received several letters urging that the ARB or another state agency set health - based standards for noise and control noise pollution. A more complete understanding of the noise and the amount and nature of dust resuspended by leaf blower use and alternative cleaning equipment is suggested to guide decision - making. Costs and benefits of cleaning methods have not been adequately quantified. Staff estimates that a study of fugitive dust generation and exposures to exhaust emissions and dust could cost $1.1 million, require two additional staff, and take two to three years. Adding a study of noise exposures and a comparison of leaf blowers to other cleaning equipment could increase study costs to $1.5 million or more (Appendix H). 5 Fugitive dust emissions are problematic. The leaf blower is designed to move relatively large materials, which requires enough force to also blow up dust particles. Banning or restricting the use of leaf blowers would reduce fugitive dust emissions, but there are no data on fugitive dust emissions from alternatives, such as vacuums, brooms, and rakes. In addition, without a more complete analysis of potential health impacts, costs and benefits of leaf blower use, and potential health impacts of alternatives, such a recommendation is not warranted. Some have suggested that part of the problem lies in how leaf blower operators use the tool, that leaf blower operators need to show more courtesy to passersby, shutting off the blower when people are walking by. Often, operators blow dust and debris into the streets, leaving the dust to be resuspended by passing vehicles. Interested stakeholders, including those opposed to leaf blower use, could join together to propose methods for leaf blower use that reduce noise and dust generation, and develop and promote codes of conduct by workers who operate leaf blowers. Those who use leaf blowers professionally would then need to be trained in methods of use that reduce pollution. and potential health impacts both for others and for themselves. M I. INTRODUCTION A. Background California Senate Concurrent Resolution No. 19 (SCR 19) was introduced by Senator John Burton February 23, 1999, and chaptered May 21, 1999 (Appendix A). The resolution requests the Air Resources Board (ARB) to prepare and submit a report to the Legislature on or before January 1, 2000, "summarizing the potential health and environmental impacts of leaf blowers and including recommendations for alternatives to the use of leaf blowers and alternative leaf blower technology if the state board determines that alternatives are necessary." The Legislature, via SCR 19, raises questions and concerns about potential health and environmental impacts from leaf blowers, and requests that ARB write the report to help to answer these questions and clarify the debate. The goal of this report, then, is to summarize for the California Legislature existing data on health and environmental impacts of leaf blowers, to identify relevant questions not answered in the literature, and suggest areas for future research. As per SCR. 19, this report includes a comprehensive review of existing studies of the impacts of leaf blowers on leaf blower operators and on the public at large, and of the availability and actual use of protective equipment for leaf blowers. The receptors identified by the resolution are humans and the environment; sources of impacts are exhaust, noise, and dust. Because the Legislature specified that ARB use existing information, staff conducted no new studies. In order to locate existing data, staff searched the published literature, contacted potential resources and experts, and requested data from the public via mail and through a web page devoted to the leaf blower report. B. History of the Leaf Blower and Local Ordinances The leaf blower was invented by Japanese engineers in the early 1970s and introduced to the United States as a lawn and garden maintenance tool. Drought conditions in California facilitated acceptance of the leaf blower as the use of water for many garden clean -up tasks was prohibited. By 1990, annual sales were over 800,000 nationwide, and the tool had become a ubiquitous gardening implement (CQS 1999a). In 1998, industry shipments of gasoline- powered handheld and backpack leaf blowers increased 30% over 1997 shipments, to 1,868,160 units nationwide (PPEMA 1999). Soon after the leaf blower was introduced into the U.S., its use was banned in two California cities, Carmel -by- the -Sea in 1975 and Beverly Hills in 1978, as a noise nuisance (CQS 1999a, Allen 1999b). By 1990, the number of California cities that had banned the use of leaf blowers was up to five. There are currently twenty California cities that have banned leaf blowers, sometimes only within residential neighborhoods and usually targeting gasoline- powered equipment. Another 80 cities have ordinances on the books restricting either usage or noise level or both. Other cities have considered and rejected leaf blower bans. Nationwide, two states, Arizona and New Jersey, have considered laws at the state level, and five other states have at least one city with a leaf blower ordinance (IME 1999). Many owners of professional landscaping companies and professional gardeners believe that the leaf blower is an essential, time- and water- saving tool that has enabled them to offer services at a much lower cost than if they had to use rakes, brooms, and water to clean up the landscape (CLCA 1999). A professional landscaper argues that the customer demands a certain level of garden clean -up, regardless of the tool used (Nakamura 1999). The issues continue to be debated in various public forums, with each side malting claims for the efficiency or esthetics of leaf blower use versus rakes and brooms. Leaf blower sales continue to be strong, however, despite the increase in usage restrictions by cities. C. Environmental Concerns The issues usually mentioned by those who object to leaf blowers are health impacts from noise, air pollution, and dust (Orange County Grand Jury 1999). The Los Angeles Times Garden Editor, Robert Smaus (1997), argues against using a leaf blower to remove dead plant material, asserting that it should be left in place to contribute to soil health through decomposition. Municipalities regulate leaf blowers most often as public nuisances in response to citizen complaints (for example, City of Los Angeles 1999). Two reports were located that address environmental concerns: an Orange County Grand Jury report (1999), and a series of reports written by the City Manager of Palo Alto (1999a, 1998a, 1998b). The purpose of the City of Palo Alto reports is to develop recommendations to the City Council on amending its existing ordinance. The Orange County Grand Jury took action to make recommendations that would "improve the quality of life in Orange County," and recommended that cities, school districts, community college districts, and the County stop using gasoline- powered leaf blowers in their maintenance and clean -up operations. The major findings of each are similar (Table 1). Table 1. Major Findings of the Orange County Grand Jury and City of Palo Alto Orange County Grand Jury Report (1999) (1) Toxic exhaust fumes and emissions are created by gas - powered leaf blowers. (2) The high - velocity air jets used in blowing leaves whip up dust and pollutants. The particulate matter (PM) swept into the air by blowing leaves is composed of dust, fecal matter, pesticides, fungi, chemicals, fertilizers, spores, and street dirt which consists of lead and organic and elemental carbon. City of Palo Alto City Manager's Report (1999x) (1) Gasoline- powered leaf blowers produce fuel emissions that add to air pollution. (2) Leaf blowers (gasoline and electric) blow pollutants including dust, animal droppings, and pesticides into the air adding to pollutant problems. (3) Blower engines generate high noise levels. Gasoline- powered leaf blower noise is a danger to the health of the blower operator and an annoyance to the non- consenting citizens in the area of usage. (3) Leaf blowers (gasoline and electric) do produce noise levels that are offensive and bothersome to some individuals. As will be discussed in more detail later in this report, the findings in these two reports about exhaust emissions and noise are substantiated in the scientific literature. The report's findings regarding dust emissions, however, were not documented or based on scientific analysis of actual emissions, but were based on common sense knowledge. The City of Palo Alto continued to examine the issue, at the behest of council members, and reported revised recommendations for the use of leaf blowers in Palo Alto in September (City of Palo Alto 1999b) and January 2000 (City of Palo Alto 2000). The City of Palo Alto subsequently voted to ban the use of fuel- powered leaf blowers throughout the city as of July 1, 2001 (Zinko 2000). D. Health and Environmental Impacts SCR 19 asks ARB to summarize potential health and environmental impacts of leaf blowers, and thus our first task is to determine what information and analysis would comprise a summary of health and environmental impacts. The methodology followed for this report is dependent both on the objectives of SCR 19 and on the available data. As staff discovered, in some areas, such as exhaust emissions, we know much; in other areas, such as fugitive dust emissions, we know very little. For both fugitive dust and noise, there are few or no data specifically on leaf blower impacts. For all hazards, there have been no dose- response studies related to emissions from leaf blowers and we do not know how many people are affected by those emissions. Therefore, staff determined to provide the Legislature with a report that has elements of both impact and risk assessments, each of which is described below. 1. Life -cycle Impact Assessment Life -cycle impact assessment is the examination of potential and actual environmental and human health effects related to the use of resources and environmental releases (Fava et al. 1993). A product's life -cycle is divided into the stages of raw materials acquisition, manufacturing, distribution/transportation, use /maintenance, recycling, and waste management (Fava et al. 1991). In this case, the relevant stage of the life -cycle is use /maintenance. Life -cycle impact assessment tends to focus on relative emission loadings and resources use and does not directly or quantitatively measure or predict potential effects or identify a causal association with any effect. Identification of the significance and uncertainty of data and analyses are important (Barnthouse 1997). 2. Risk Assessment A traditional risk assessment, on the other hand, seeks to directly and quantitatively measure or predict causal effects. A risk assessment evaluates the toxic properties of a chemical or other hazard, and the conditions of human exposure, in order to characterize the nature of effects and determine the likelihood of adverse impacts (NRC 1983). The four components of a risk assessment are: Hazard identification: Determine the identities and quantities of chemicals present, the types of hazards they may produce, and the conditions under which exposure occurs. Dose - response assessment: Describe the quantitative relationship between the amount of exposure to a substance (dose) and the incidence of adverse effects (response). Exposure assessment: Identify the nature and size of the population exposed to the substance and the magnitude and duration of their exposure. Risk characterization: Integrate the data and analyses of the first three components to determine the likelihood that humans (or other species) will experience any of the various adverse effects associated with the substance. The goal of risk assessment is the quantitative characterization of the risk, i.e., the likelihood that a certain number of individuals will die or experience another adverse endpoint, such as injury or disease. A risk assessment is ideally followed up by risk management, which is the process of identifying, evaluating, selecting, and implementing actions to reduce risk to human health and ecosystems (Omenn et al. 1997). While a risk assessment appears to be preferable because it allows us to assign an absolute value to the adverse impacts, a quantitative assessment is difficult, if not impossible, to perform when data are limited. E. Public Involvement To facilitate public involvement in the process of preparing the leaf blower report, staff mailed notices using existing mailing lists for small off -road engines and other interested parties, posted a leaf blower report website, met with interested parties, and held two public workshops, in June and September, 1999. In addition to face -to -face meetings and workshops, staff contacted interested parties through numerous telephone calls and e- mails. A list of persons contacted for this report is found in Appendix B. Letters and documents submitted to the Ai Resources Board as of December 15, 1999, are listed in Appendix K. The vast majority of those contacted were very helpful, opening their files and spending time answering questions. ARB staff were provided with manufacturer brochures; unpublished data; old, hard -to -find reports and letters; and given briefings and demonstrations. Many reports have been posted on the Internet, for downloading at no cost, which considerably simplified the task of tracking down significant works and greatly reduced the cost of obtaining the reports. 10 F. Overview of this Report The main body of this report comprises four additional sections, followed by the references cited and appendices. Section II describes the hazards, as identified in SCR 19, from leaf blowers. Hazardous components of exhaust emissions, fugitive dust emissions, and noise are covered in turn, along with who is exposed to each hazard and how society has sought to control exposure to those hazards through laws. Section III reviews health effects of each of the hazards, with exhaust emissions subdivided into particulate matter, carbon monoxide, ozone, and toxic constituents of burned and unburned fuel. Health effects from fugitive dust are covered in the subsection on particulate matter. Section IV discusses the potential health and environmental impacts of leaf blowers, synthesizing the information presented in Sections 11 and 111. Section V discusses recommendations. Additional information, including a discussion of research needs to make progress toward answering some of the questions raised by this report, a description of engine technologies that could reduce exhaust emissions and alternatives to gasoline- powered leaf blowers, and a complete bibliography of materials received and consulted but not cited in the report, is found in the appendix. 11 II. DESCRIPTION OF THE HAZARDS This section of the report describes the three potential hazards identified by SCR 19 as resulting fiom leaf blowers. This report examines the three hazards that have been of most concern of the public and the Legislature. Hazard identification is the first step in an impact or risk assessment. In this section, then, each of the three identified hazards are examined in turn, exhaust emissions, dust emissions, and noise. For each, the hazard is described and quantified, and the number of people potentially exposed to the hazard is discussed. For exhaust emissions, the number of people potentially impacted is as high as the population of the state, differing within air basins. Fugitive dust emissions impact a varying number of people, depending on one's proximity to the source, the size of the particles, and the amount of time since the source resuspended the particles. Finally, in this section we also discuss laws that control the particular hazard. A. Exhaust Emissions Exhaust emissions are those emissions generated from the incomplete combustion of fuel in an engine. The engines that power leaf blower equipment are predominantly two- stroke, less than 25 horsepower (hp) engines. This section describes the two- stroke engine technology prevalent in leaf blower equipment and associated emissions, reviews the leaf blower population and emission inventory data approved by the Board in 1998, and describes federal, state, and local controls on small off -road engines. 1. Characterization of Technology Small, two- stroke gasoline engines have traditionally powered leaf blowers, and most still are today.' The two- stroke engine has several attributes that are advantageous for applications such as leaf blowers. Two - stroke engines are lightweight in comparison to the power they generate, and operate in any position, allowing for great flexibility in equipment applications. Multi- positional operation is made possible by mixing the lubricating oil with the fuel; the engine is, thus, properly lubricated when operated at a steep angle or even upside down. A major disadvantage of two- stroke engines is high exhaust emissions. Typical two- stroke designs feed more of the fuel/oil mixture than is necessary into the combustion chamber. Through a process known as scavenging, the incoming fuel enters the combustion chamber as the exhaust is leaving. This timing overlap of intake and exhaust port opening can result in as much as 30% of the fuel /oil mixture being exhausted unburned. Thus, exhaust emissions consist of both unburned fael and products of incomplete combustion. The major pollutants from a two- stroke engine are, therefore, oil -based particulates, a mixture of hydrocarbons, and carbon monoxide. A two- stroke engine forms relatively little oxides of nitrogen emissions, because the extra fuel absorbs the heat and keeps peak combustion temperatures low. 'Unless otherwise referenced, this section makes use of material in the ARB's Small Off Road Engine staff report and attachments, identified as MSC 98 -02; 1998a. 12 Hydrocarbon emissions, in general, combine with nitrogen oxide emissions from other combustion sources to produce ozone in the atmosphere. Thus ozone, although not directly emitted, is an additional hazard from leaf blower exhaust. In addition, some of the hydrocarbons in fuel and combustion by- products are themselves toxic air contaminants, such as benzene, 1,3- butadiene, acetaldehyde, and formaldehyde (ARB 1997). The major sources of benzene emissions are gasoline fugitive emissions and motor vehicle exhaust; about 25% of benzene emissions are attributed to off -road mobile sources. Most 1,3- butadiene emissions are from incomplete combustion of gasoline and diesel fuels from mobile sources (about 96 %). Sources of acetaldehyde include emissions from combustion processes and photochemical oxidation. The ARB has estimated that acetaldehyde emissions from off -road motor vehicles comprise about 27% of the total emissions. Finally, formaldehyde is a product of incomplete combustion and is also formed by photochemical oxidation; mobile sources appear to contribute a relatively small percentage of the total direct emissions of formaldehyde. Data do not exist to allow reliable estimation. of-toxic air contaminant emissions from small, two- stroke engine exhaust. A small percentage of blowers utilize four - stroke engines. These blowers are typically "walk- behind" models, used to clean large parking lots and industrial facilities, rather than lawns and driveways. Overall, the engines used in these blowers emit significantly lower emissions than their two- stroke counterparts, with significantly lower levels of hydrocarbons and particulate matter. These four - stroke blower engines have a significantly lower population than the traditional two- stroke blowers and only peripherally fit the definition or commonly- accepted meaning of the term "leaf blower." They. are mentioned here only for completeness, but are not otherwise separately addressed in this report. 2. Exhaust Emissions a. Leaf Blower Population The best estimates available indicate that there are approximately 410,000 gasoline - powered blowers in use in the state today. Less than 5,000 of those use four - stroke engines; the remainder (99 %) utilize two - stroke engines. These data have been developed from information gathered through the development and implementation of ARB's small off -road engine regulation. Since the small off -road engine regulation does not apply to blowers powered by electric motors, data regarding the number of electric blowers are not as extensive. However, information shared by the handheld power equipment industry indicates that approximately 60 percent of blowers sold are electric. This would indicate that there are approximately 600,000 electric blowers in California. It must be stressed that the majority of the blower population being electric does not imply that the majority of usage accrues to electric blowers. In fact, electric blowers are more likely to be used by homeowners for occasional use, whereas virtually all professional gardeners use engine - powered blowers. b. Emission Inventory 13 California's emission inventory is an estunate of the amount and types of criteria pollutants and ozone precursors emitted by all sources of air pollution. The emission inventory method and inputs for small off -road engines, with power ratings of less than 25 hp, were approved by the Board in 1998 (ARB 1998b) (Table 2). Exhaust emissions from leaf blowers contribute from one to nine percent of the small -off road emissions, depending on the type of pollutant, based on the 2000 emissions data. Exhaust emission standards for small off -road engines, which will be implemented beginning in 2000, will result in lower emissions in the future. By 2010, for example, hydrocarbon emissions are expected to shrink by 40% statewide, while CO declines by 35% and PM10 drops 90 %. The reductions reflect the replacement of today's blowers with cleaner blowers meeting the 2000 standards. Table 2. Statewide Inventory of Leaf Blower Exhaust Emissions (tons per day) 3. Regulating Exhaust Emissions a. State Regulations The California Clean Air Act, codified in the Health and Safety Code Sections 43013 and 43018, was passed in 1988 and grants the ARB authority to regulate off -road mobile source categories, including leaf blowers. The federal Clean Air Act requires states to meet national ambient air quality standards (Appendix C) under a schedule established in the Clean Air Act Amendments of 1990. Because many air basins in California do not meet some of these standards, the State regularly prepares and submits to the U.S. EPA a plan that specifies measures it will adopt into law to meet the national standards. Other feasible measures not specified in the state implementation plan may also be adopted as needed. In December 1990, the Board approved emission control regulations for new small off -road engines used in leaf blowers and other applications. The regulations took effect in 1995, and include exhaust emission standards, emissions test procedures, and provisions for warranty and production compliance programs. In March of 1998, the ARB amended the standards to be implemented with the 2000 model year (ARB 1998a). Table 3 illustrates how the standards compare with uncontrolled engines for leaf blower engines. Note that there was no particulate 14 Leaf blowers Leaf blowers All Lawn & All Small Off - 2000 2010 . _Garden, 2000 Road 2000 Hydrocarbons, 7.1 4.2 50.24 80.07 reactive Carbon Monoxide 16.6 9.8 434.99 1046.19 CO Fine Particulate 0.2 0.02 1.05 3.17 Matter (PM10) 3. Regulating Exhaust Emissions a. State Regulations The California Clean Air Act, codified in the Health and Safety Code Sections 43013 and 43018, was passed in 1988 and grants the ARB authority to regulate off -road mobile source categories, including leaf blowers. The federal Clean Air Act requires states to meet national ambient air quality standards (Appendix C) under a schedule established in the Clean Air Act Amendments of 1990. Because many air basins in California do not meet some of these standards, the State regularly prepares and submits to the U.S. EPA a plan that specifies measures it will adopt into law to meet the national standards. Other feasible measures not specified in the state implementation plan may also be adopted as needed. In December 1990, the Board approved emission control regulations for new small off -road engines used in leaf blowers and other applications. The regulations took effect in 1995, and include exhaust emission standards, emissions test procedures, and provisions for warranty and production compliance programs. In March of 1998, the ARB amended the standards to be implemented with the 2000 model year (ARB 1998a). Table 3 illustrates how the standards compare with uncontrolled engines for leaf blower engines. Note that there was no particulate 14 matter standard for 1995 -1999 model year leaf blowers, but that a standard will be imposed beginning with the 2000 model year. Among other features of the small off -road engine regulations is a requirement that production engines be tested to ensure compliance. Examination of the certification data confirms that manufacturers have been complying with the emissions regulations; in fact, engines that have been identified as being used in blowers tend to emit hydrocarbons at levels that are 10 to 40 percent below the existing limits. This performance is consistent with engines used in string trimmers, edgers, and other handheld -type equipment, which are, in many cases, the same engine models used in leaf blowers. Table 3 Exhaust Emissions Per Engine for Leaf Blowers (grams per brake - horsepower -hour, g /bhp -hr) b. Federal Regulations Although the federal regulations for mobile sources have traditionally followed the ARB's efforts, the U.S. EPA has taken advantage of some recent developments in two- stroke engine technology. Specifically, compression wave technology has been applied to two- stroke engines, making possible much lower engine emissions. Bolstered by this information, the U.S. EPA (1999a) has proposed standards for blowers and other similar equipment that would be more stringent than the ARB standards. ARB plans a general review of off -road engine technology by 2001, and will consider the implications of this new technology in more detail then. A short description is included in Appendix I. c. South Coast AOMD Emissions Credit Program 2Applicable to engines of 20 -50 cc displacement, used by the vast majority of leaf blowers. 3For yr 2000, the HC + NOx standards have been combined. 4There was no particulate standard for this time period. 15 Uncontrolled Emissions 1995 -1999 StandardS2 2000 and later Standards HC +NOx 283+1.0 180+4.0 543 CO 908 600 400 PM 3.6 --- 1.5 b. Federal Regulations Although the federal regulations for mobile sources have traditionally followed the ARB's efforts, the U.S. EPA has taken advantage of some recent developments in two- stroke engine technology. Specifically, compression wave technology has been applied to two- stroke engines, making possible much lower engine emissions. Bolstered by this information, the U.S. EPA (1999a) has proposed standards for blowers and other similar equipment that would be more stringent than the ARB standards. ARB plans a general review of off -road engine technology by 2001, and will consider the implications of this new technology in more detail then. A short description is included in Appendix I. c. South Coast AOMD Emissions Credit Program 2Applicable to engines of 20 -50 cc displacement, used by the vast majority of leaf blowers. 3For yr 2000, the HC + NOx standards have been combined. 4There was no particulate standard for this time period. 15 The South Coast Air Quality Management District (SCAQMD), an extreme non - attainment area for ozone, has promulgated Rule 1623 - Credits for Clean Lawn and Garden Equipment. Rule 1623 provides mobile source emission reduction credits for those who voluntarily replace old high- polluting lawn and garden equipment with new low- or zero- emission equipment or who sell new low- or zero - emission equipment without replacement. The intent of the rule is to accelerate the retirement of old high - polluting equipment and increase the use of new low- or zero - emission equipment. In 1990, volatile organic carbon emissions from lawn and garden equipment in the South Coast Air Basin were 22 tons per day (SCAQMD 1996). To date, no entity has applied for or received credits cinder Rule 1623 (V. Yardemian, pers. com.) 4. Summary Exhaust emissions fiom leaf blowers consist of the following specific pollutants of concern: hydrocarbons from both burned and unburned Riel, and which combine with other gases in the atmosphere to form ozone; carbon monoxide; fine particulate matter; and other toxic air contaminants, including benzene, 1,3- butadiene, acetaldehyde, and formaldehyde. Exhaust emissions from these engines, while high compared to on -road mobile sources on a per engine basis, are a small part of the overall emission inventory. Emissions have only been controlled since 1995, with more stringent standards taking effect in 2000. The exhaust emissions from leaf blowers are consistent with the exhaust emissions of other, similar off -road equipment powered by small, two- stroke engines, such as string trimmers. Manufacturers have developed several different methods to comply with the standards and have done an acceptable job certifying and producing engines that are below the regulated limits. Electric- powered models that are exhaust - free are also available. B. Fugitive Dust Emissions "Blown dust" is the second of the hazards from leaf blowers specified in SCR 19. For the purposes of this report, we will use the term "fugitive dust," which is consistent with the terminology used by the ARB. This section, in addition to defining fugitive dust emissions, characterizes fugitive dust resuspended by leaf blowers by comparing previous estimates of emission factors (amount emitted per hour per leaf blower) and emissions inventory (amount resuspended per day by all leaf blowers statewide) to a current estimate, developed for this report. In addition, the potential composition of leaf blower dust and fugitive dust controls at the state and local levels are described. 16 1. Definition of Fugitive Dust Emissions From the Glossary of Air Pollution Terms, available on the ARB's website,s the following definitions are useful: Fugitive Dust: Dust particles that are introduced into the air through certain activities such as soil cultivation, or vehicles operating on open fields or dirt roadways; a subset of fugitive emissions. Fugitive Emissions: Emissions not caught by a capture system (often due to equipment leaks, evaporative processes, and windblown disturbances). Particulate Matter (PM): Any material, except uncombined water, that exists in the solid or liquid state in the atmosphere. The size of particulate matter can vary from coarse, wind -blown dust particles to fine particle combustion products. Fugitive dust is a subset of particulate matter, which is a complex mixture of large to small particles-that are directly emitted-or formed in the-air. Current control efforts focus on PM small enough to be inhaled, generally those particles smaller than 10 micrometers (um). So- called coarse particles are those larger than 15 um in diameter, and are directly emitted from activities that disturb the soil, including construction, mining, agriculture, travel on roads, and landfill operations, plus windblown dust, pollen, spores, sea salts, and rubber from brake and tire wear. Those with diameters smaller than 2.5 ,um are called fine particles. Fine particles remain suspended in the air for long periods and can travel great distances. They are formed mostly from combustion sources, such as vehicles, boilers, furnaces, and fires, with a small dust component. Fine particles can be directly emitted as soot or formed in the atmosphere as combustion products react with gases from other sources (Finlayson -Pitts & Pitts 1986). - Dust emissions from leaf blowers are not part of the inventory of fugitive dust sources. ARB, therefore, does not have official data on the quantity of fugitive dust resuspended by leaf blowers. No data on the amount and size distributions of resuspended dust from leaf blower activities have been collected, although estimates have been made. ARB evaluated three previous estimates (McGuire 1991, Botsford et al. 1996, Covell 1998) and developed a proposed methodology for estimating fugitive dust emissions from leaf blowers. The estimate presented below begins with the assumptions and calculations contained in the study conducted for the SCAQMD by AeroViromnent (Botsford et al. 1996)..Additional methodologies and data have been reviewed and derived from the U.S. EPA document commonly termed AP -42, and reports by the Midwest Research Institute; University of California, Riverside; and the Desert Research Institute. 'http://arbis.arb.ca.gov/html/gloss.htn-i 17 2. Calculating Leaf Blower Emissions There are more than 400,000 gasoline- powered leaf blowers, plus approximately 600,000 electric leaf blowers, that are operated an estimated 114,000 hours per day in California. The fundarnental premise in the calculations below is that leaf blowers are designed to move relatively large materials such as leaves and other debris, and hence can also be expected to entrain into the air much smaller particles, especially those below 30 ,um diameter, which are termed total suspended particulate (PMtsp). Subsets of PMtsp include PM10, particulates with diameters less than or equal to 10 gm, and PM2.5, particulates with diameters less than or equal to 2.5 µm. Particles below 30 gm are not visible to the naked eye. Note that PM 10 includes PM2.5 particles, and PMtsp includes PM 10 and PM2.5 particles. a. Generation of Fugitive Dust by Leaf Blowers The leaf blower moves debris such as leaves by pushing relatively large volumes of air, typically between 300 -700 cubic feet per minute, at a high wind speed, typically 150 to 280 miles per hour (hurricane wind speed is >117 mph). A typical surface is covered with a layer of dust that is spread, probably non - uniformly, along the surface being cleaned. While the intent of a leaf blower operator may not be to move dust, the high wind speed and volume result in small particles being blown into the air. In order to calculate how much fugitive dust is generated by the action of a blower, we assume that this layer of dust can be represented by a single average number, the silt loading. This silt loading value, when combined with the amount of ground cleaned per unit time and the estimated PM weight fractions, produces estimates of fugitive dust emissions from leaf blowers. Staff have located no fugitive dust measurement studies on leaf blowers, but have found previous calculations of fugitive dust estimates from leaf blowers. Based on a review of those estimates, staff applied the latest knowledge and research in related fields in order to derive a second -order approximation. This section presents the best estimates using existing data, while recognizing that estimates are only approximations. Variables that would affect fugitive dust emissions, and for which ARB has little or no empirical data, include, for example: (1) the specific surface types on which leaf blowers are used; (2) the percentage of use on each specific surface type; (3) effects of moisture, humidity, and temperature; (4) silt loading values for surfaces other than paved roadways, shoulders, curbs, and gutters and in different areas of the state; and (5) measurements of the amount of surface cleaned per unit time by the average operator. Other variables are not expected to greatly influence fugitive dust emissions; the hurricane -force winds generated by leaf blowers are expected to overcome such influences, for example, as the roughness of relatively flat surfaces and the effect of particle static charge. 18 b. Size Segregation of Particulate Matter PM emissions can be subdivided into the following three categories, operator emissions, local emissions, and regional emissions. They are differentiated as follows: 1) Operator emissions. PMtsp emissions approximate emissions to which the operator is exposed. The larger of these particles, between approximately 10 and 30 gm, have relatively short settling times, on the order of minutes to a couple of hours, maximum (Finlayson -Pitts & Pitts 1986, Gillies et al. 1996, Seinfeld & Pandis 1998). These would be emissions to which both the leaf blower operator and passersby would be exposed. 2) Local emissions. PM10 emissions will be used to estimate "local" PM emissions. PM10, which includes particles at or below 10 µm, may remain suspended for hours to days in the atmosphere (Finlayson -Pitts & Pitts 1986, Gillies et al. 1996, Seinfeld & Pandis 1998). These are emissions to which persons in the near- downwind- vicinity would be exposed, for example, residents whose lawns are being serviced and their neighbors, persons in commercial buildings whose landscapes are being maintained or serviced, and persons within a few blocks of the source. 3) Regional emissions. PM2.5 emissions may remain suspended for as long as a week or more (Finlayson -Pitts & Pitts 1986, Gillies, et al. 1996, Seinfeld & Pandis 1998). These particles are sized at or below 2.5 µm, and hence can be considered as contributors to regional PM emissions over a county or air basin because of their long residence time. c. Calculation Assumptions and Limitations The method presented uses the following assumptions. 1) Methods used for estimating wind blown dust for paved roads can be applied to estimating fugitive dust emissions from leaf blowers. That is, one can use an "AP -42" type (U.S. EPA 1997) of approach that calculates dust emissions based on the silt loading of the surfaces in question. 2) The typical leaf blower generates sufficient wind speed to cause sidewalk/roadway dust, in particular, particles 30 µm or less in aerodynamic diameter, to become airborne. The AeroViromnent study (Botsford et al. 1996) assumed that nozzle air velocities ranged from 120 to 180 mph, and calculated that wind speed at the ground would range from 24 mph to 90 mph, sufficient to raise dust and equivalent, at the middle to high end speeds, to gale -force winds. 3) Currently available paved road, roadside shoulder, and gutter silt loadings (Venkatram & Fitz 1998) can be used to calculate emissions from leaf blowers, as there are no data on silt loadings on other surfaces. Observations and communications with landscapers indicate that leaf blowers are most commonly used to clean hardscape surfaces, such as sidewalks, after lawns and 19 flower beds have been trimmed and cuttings left on hardscapes. Debris is then frequently blown into the roadway before being collected for disposal. 4) The size fractions for particles for paved road dust can be used to calculate emissions from leaf blowers (G. Muleski, pegs. comm.). The ratios of particle size multipliers, or "k" factors, are used to estimate the weight fraction of windblown dust for leaf blower usage. The "lc" factor is a dimensionless value that represents the percentage of the total dust loading that is of a certain size fraction (MRI 1997). 5) Silt loading values and usage are assumed to be the same for residential and commercial leaf blower use. In an earlier draft, ARB staff had proposed different silt loading values for residential and commercial leaf blowers; comments were received that indicated that heavier -duty commercial leaf blowers were used in the same way in both residential and commercial settings. In addition, data on nozzle air speeds indicate that most electric leaf blowers, targeted at homeowners, have air speeds at or above 120 mph, the lowest air speed considered in the AeroVironment report (Botsford et al. 1996) as capable of raising dust. 6) The weight of total suspended particulates is equivalent to 100% of the silt loading, the weight fraction that comprises PM10 is 19% of the total, and the weight fraction comprising PM2.5 is 9% of the total (U.S. EPA 1997, MRI 1997, G. Muleski, pers. com). A recent study, however, found that 50 -70% of the mass of PMtsp of paved road dust at three southern California locations is present in the PM10 fraction (Miguel et al. 1999), so more data would be helpful. A final limitation is the recognition that emissions inventories are estimates of the unknown and unknowable actual emissions inventory. An earlier draft of this report was criticized as providing only estimates of emissions, and not actual emissions, when hi fact all emissions inventories are based on models developed through scientific research on how the chemicals behave in the atmosphere, limited testing to determine emission factors, and industry- provided data on the population and usage of each particular source of air pollution. Each generation of emission inventories is an improvement over the one previous as assumptions are examined, tested, and modified. As discussed earlier, the estimate in this report builds on previous estimates. d. Calculation Methodoloiy The proposed emissions estimation methodology uses measured silt loadings (Venkatram & Fitz 1998) and size fraction multipliers for PM10 and PM2.5 (U.S. EPA 1997, MRI 1997, G. Muleski, pers. com.). EFsize = (sL) (Q) (fsize) where: EFs;Ze = PM30, or PM10, or PM2.5 emission factors; sL = silt loading fraction, from ARB (1998b); 20 Q = amount of ground cleaned per unit time, estimated to be 1,600 m2/hr, corresponding to a forward speed of 1 mph, with the operator sweeping the blower in a one meter arc; f,i,e fraction of PMtsp dust loading that comprises PM10 (0.19) or PM2.5 (0.09). Silt loading values are the critical parameter in the calculation. ARB has chosen, for this emissions estimate, to use recent data from a study conducted for the ARB by a team at the University of California, Riverside (Venkatram & Fitz 1998) (Table 4). As data were collected only in Riverside County, it is not known how representative they are of other areas of the state or of substrates cleaned by leaf blowers. The data are, however, the most complete we have to date. Because the data are not normally distributed, the median and 95% percentile samples for silt loading are used to represent the data set in calculations. Table 4 Silt Loading Values, Riverside County (grams per square meter, g /m2) Roadway Type Material Loading, Median Silt Loading, Median (95 %) Range of Silt Loading Values Paved Road 108.44 0.16 (6.34) 0.003 - 107.596 Roadway Shoulders 481.08 3.33 (15.73) 0.107- 23.804 Curbs and Gutters 144:92 3.39 (132.94) 0.97 - 556.65 3. Characterization of Fugitive Dust Emissions This section includes results from this present analysis, as well as results from previous estimates prepared by the ARB and others for comparison. a. Emission Factors - This Study Possible emission factors have been calculated for leaf blower use on paved roadways, roadway shoulders, and curbs and gutters (Table 5). Two emission factors are presented for each surface and particle size, based on the median and 95t" percentile of the empirical silt loading data. The resulting range for PM10 is from 48.6 to 1030.6 g/hr for PM10, for example, depending on the surface cleaned. Cleaning of curbs and gutters generates the highest emission factors, whereas paved roadways and shoulders are lower. As discussed before, staff have no data on which to base emission factors for sidewalks, driveways, lawns, or flower beds. 21 Table 5. Leaf Blower Estimated Emission Factors, This Study (grams per hour, g/hr) Emission Factor Paved Roadway, Median 95% Shoulders, Median 95% Curbs /Gutters, Median 95% Total Suspended Particulate 256.0 (10,144.0) 5,328 (25,168) 5,424 (212,704). PM10 48.6 1,927.4 1,012.3 (4,781.9 ) 1,030.6 (40,413.8 PM2.5 23.0 (913.0) 479.5 (2,265.0) 488.2 (19,143.4) b. Statewide Emissions Inventory - This Study Three potential statewide emissions inventory values (Table 6), in tons per day (tpd), have been calculated by multiplying the median emissions factors, shown above, by the hours of operation for each of three different substrates: paved roadways, paved shoulders, and paved curbs /gutters, based on the Riverside data. From the statewide emissions inventory, the total number of hours of operation in the year 2000 are estimated to be 113,740 hr /day, or 97,302 hr /day for gasoline- powered leaf blowers plus 16,438 hr /day for electric leaf blowers.6 Table 6. Leaf Blower Emissions, Possible Statewide Values, This Study (tons per day, tpd) Emissions Inventory Paved Roadway, Median Shoulders, Median Curbs /Gutters, Median Total Suspended Particulates 32.1 667.4 679.4 PM10 6.1 126.8 129.1 PM2.5 2.9 60.1 61:2 The goal in developing an emissions inventory is to derive one statewide emissions inventory number for each category of particulate sizes, which can then be subdivided by air basin or air district. Ideally, ARB would have developed emissions factors for each surface cleaned by leaf blowers, and apportioned the emissions based on the percentage of hours spent cleaning each surface annually. Table 6, however, presents an array of values because staff have no data on the percentage of time spent cleaning various surfaces. For comparison, the 1996 statewide PM10 6 O a per -unit basis, electric blowers are assumed to be used 10 hr /yr. 22 estimated emission inventory was 2,400 tpd; estimates for paved road dust, unpaved road dust, and fugitive windblown dust were 400, 610, and 310 tpd, respectively. Based on the estimates in Table 6, then, PM10 emissions impacts from leaf blower use could range from insignificant (0.25 %) to significant (5.4 %), on a statewide basis. Additional study is required to refine the analysis and develop a statewide emission inventory. c. Previous Emissions Estimates: ARB, 1991 The ARB's Technical Support Division, in a July 9, 1991 response to a request from Richard G. Johnson, Chief of the Air Quality Management Division at the Sacramento Metropolitan Air Quality Management District, prepared a leaf blower emissions estimate in grams per hour of dust (McGuire 1991). PM10 emissions were reported as being 1,180 g/hr, or 2.6 lb/hr, which is the same order of magnitude as the present study's calculated emission factors for roadway shoulders and curbs /gutters (Table 5). If this emission factor is combined with current statewide hours -of- operation data of 113,740 hr /day of leaf blower usage, this would produce an emission inventory of 147.8 tpd of PM10, similar to the present study's inventory for shoulders and curbs /gutters (Table 6). d. Previous Emissions Estimates: SMAQMD Sacramento Metropolitan Air Quality Metropolitan District ( SMAQMD) staff (Covell 1998) estimated that "Dust Emissions (leaf blowers only)" are 3.2 tpd in Sacramento County. The memo included commercial and residential leaf blower populations (1,750 commercial and 15,750 residential), and hours of use (275 hr /yr for commercial and 10 hr /yr for residential). Using these values one can calculate the assumed g/hr emission factor for particulate matter. The resulting emission factor is 1,680 g/hr, or 3.7 lb /hr. The resulting statewide emission inventory is 210.4 tpd, higher than this study's estimates (Tables 5 & 6). e. Previous Emissions Estimates: AeroVironment .The South Coast AQMD commissioned AeroVironment to determine emission factors and preliminary emission inventories for sources of fugitive dust previously uninventoried; leaf blowers were one of the categories examined (Botsford et al. 1996). The study focused on PM10, and did not include field measurements. The study assumed that each leaf blower was used, at most, one day per week to clean 92.9 m2 (1000 ft?) of ground. Silt loading was assumed to be 1.42 g /m2 Combining these two values yields an emission factor of 5.5 g /hr. With an estimated 60,000 leaf blowers in the South Coast Air Basin, AeroViromment calculated an emission inventory of 8.6 tpd, just for the South Coast AQMD, more than double the basin -wide inventory calculated for the Sacramento Metropolitan AQMD (above). The obvious difference between this estimate and the others summarized herein is the assumption that each leaf blower is used for no more than one day per week and is used to clean an area equivalent to only one front yard (20 ft by 50 ft); as commercial gardeners could not make a living cleaning one front yard once per week, this figure is obviously much too low. It is, however, coincidentally similar to the present study's estimate for paved roadways (Table 6). 23 4. Particulate Composition Substances such as fecal material, fertilizers, fungal spores, pesticides, herbicides, pollen, and other biological substances have been alleged to make up the dust resuspended by leaf blower usage (Orange County Grand Jury 1999), and thus staff looked for data on the composition of particulate matter. Little information is available. Suspended paved road dust is a major contributor to airborne particulate matter in Los Angeles and other cities (Miguel et al. 1999). Staff considered, therefore, size - segregated chemical speciation profiles for paved road dust to chemically characterize leaf blower PM emissions. The chemical speciation profiles for paved road dust show small percentages of the toxic metals arsenic, chromium, lead, and mercury. In addition to soil particles, paved road dust emissions may contain contributions from tire and brake wear particles. Paved road dust chemical speciation, however, characterizes the dust by elemental composition, and was not useful in estimating health impacts for this assessment. ARB's chemical speciation profile for paved road dust is presented in Appendix D for information. Recently, however, researchers published a study on alleigans in paved road dust and airborne particles (Miguel et al. 1999). The authors found that biologic materials from at least 20 different source materials known to be capable of causing or exacerbating allergenic disease in humans are found in paved road dust, including pollens and pollen fragments, animal dander, and molds. Allergen concentrations in the air are increased above the levels that would otherwise occur in the absence of suspension by passing traffic. The authors conclude that paved road dust is a ubiquitous mixed source of allergenic material, resuspended by passing traffic, and to which virtually the entire population is exposed. The applicability of this study to particulate matter resuspension by leaf blower usage is unknown, but it is likely that leaf blowers would be as effective at resuspending paved road dust as automobiles. Information on the characteristics of other sources of resuspended particulates, for example lawns and gardens, is unfortunately lacking. 5. Regulating Fugitive Dust Emissions Fugitive dust emissions are generally regulated as a nuisance, although PM10 and PM2.5 are specifically addressed through the state planning process as criteria air pollutants. There are no explicit federal, state, or local regulations governing leaf blower fugitive dust emissions. 24 a. State and Federal PM10 and PM2.5 Standards The California and Federal ambient air quality standards for PM10 and PM2.5 are located in Appendix C. Any state that has air basins not in attainment with the standards must submit a plan to U.S. EPA on how they will achieve compliance. For California, most of the state violates the PM10 standard; attaimnent status has not yet been determined for the new PM2.5 standard (promulgated July 18, 1997 and under challenge in the courts). California, and its air districts, is therefore required to control sources of PM10, including fugitive dust. b. Local District Regulations Many air districts have a fugitive dust control rule that prohibits activities that generate dust beyond the property line of an operation. For example, the SCAQMD Rule 403 states: "A person shall not cause or allow the emissions of fugitive dust from any active operation, open storage pile, or undisturbed_surface area such.:that_the presence of such dust remains visible in the atmosphere beyond the property line of the emission source." In addition, rules may place limits on the amount of PM10 that can be detected downwind of an operation that generates fugitive dust; for SCAQMD that limit is 50 gghn3 [ SCAQMD Rule 403]. The Mojave AQMD limits PM emissions to 100 dig /m3 [Mojave AQMD Rule 403]. Others, such as the San Joaquin Unified APCD, define and limit visible emissions (40% opacity) from activities that generate fugitive dust emissions [SJUAPCD Rule 8020]. Finally, another approach is to simply request individuals take reasonable precautions to prevent visible particulate matter emissions from moving beyond the property from which the emissions originate [Great Basin Unified APCD Rule 401 ]. 6. Summary Data on fugitive dust indicate that the PM10 emissions impacts from dust suspended by leaf blowers are small, but probably significant. Previous emission estimates range from less than 1% to 5% of the statewide PM10 inventory. The ARB previously estimated statewide fugitive dust emissions to be about 5 percent of the total, the Sacramento Metropolitan AQMD estimated leaf blower fugitive dust emissions to be about 2 percent of the Sacramento county PM10 air burden, and AeroVironment estimated dust attributed to leaf blowers in the South Coast Air Basin to be less than 1% of all fugitive dust sources. Dust emissions attributable to leaf blowers are not part of the inventory of fugitive dust sources. ARB, therefore, does not have official data on the quantity of fugitive dust resuspended by leaf blowers. A more definitive estimate of leaf blower fugitive dust emissions will require research to verify appropriate calculation parameters, determine representative silt loadings, measure actual fugitive dust emissions through source testing, and identify the chemical composition of leaf blower - generated fugitive dust. 25 C. Noise Emissions The third of the hazards from leaf blowers identified in SCR 19 is noise. This section defines noise, describes the physical properties of sound and how sound loudness is measured, discusses noise sources, the numbers of Californians potentially exposed to noise, and how noise is regulated at the federal, state, and local levels, and addresses specific sound loudness and quality fiom leaf blowers. In addition, the incidence of the use of hearing protection, and other personal protective equipment, by leaf blower operators is described. 1. Defining Noise Noise is the general term for any loud, unmusical, disagreeable, or unwanted sound. In addition to damaging hearing, noise causes other adverse health impacts, including interference with communication, rest and sleep disturbance, changes in performance and behavior, annoyance, and other psychological and physiological changes that may lead to poor health (Berglund & Lindvall 1995). In this report, noise will be used to refer both to unwanted sounds and sounds that damage hearing. The two characteristics, although related, do not always occur together. The effects of sound on the ear are determined by its quality, which consists of the duration, intensity, frequency, and overtone structure, and the psychoacoustic variables of pitch, loudness, and tone quality or timbre, of the sound. Long duration, high intensity sounds are the most damaging and usually perceived as the most annoying. High frequency sounds, up to the limit of hearing, tend to be more annoying and potentially more hazardous than low frequency sounds. Intermittent sounds appear to be less damaging than continuous noise because the ear appears to be able to recover, or heal, during intervening quiet periods. Random, intermittent sounds, however, may be more annoying, although not necessarily hazardous, because of their unpredictability (Suter 1991). The context of the sound is also important. While certain sounds may be desirable to some people, for example, music at an outdoor party, others may consider them noise, for example, those trying to sleep. Even desirable sounds, such as loud music, may cause damage to hearing and would be considered noise in this context. Thus, not only do loudness, pitch, and impulsiveness of sound determine whether the sound is noise, but also the time of day, duration, . control (or lack thereof), and even one's personality determine whether sounds are unwanted or not. The physical and psychoacoustic characteristics of sound, and thus noise, are described in more detail in Appendix E. The discussion is focused on information necessary for the reader to understand how sound is measured, and clarify measures of leaf blower sound. The interested reader is referred for more information to any physics or acoustic reference book, or the works referred to herein. 26 2. Measuring the Loudness of Sound The weakest intensity of sound a health human ear can detect has an amplitude of 20 millionths of a Pascal' (20 µPa). The loudest sound the human ear can tolerate, the threshold of pain, has an amplitude ten million times larger, or 200,000,000 µPa. The range of sound intensity between the faintest and the loudest audible sounds is so large that sound pressures are expressed using a logarithmically compressed scale, termed the decibel (dB) scale. The decibel is simply a unit of comparison between two sound pressures. In most cases, the reference sound pressure is the acoustical zero, or the lower limit of hearing. The decibel scale converts sound pressure levels (SPL) to a logarithmic scale, relative to 20 gPa (Figure 1). SPL, dB = 10 loglo (p2/p"2) Where P is the pressure fluctuation in Pascals, P, is the reference pressure; usually 20 /tPa. Thus, from this relationship, each doubling of sound pressure levels results in an increase of 6 dB. From the relationship between sound intensity and distance (Appendix E), we find also that doubling the distance between the speaker (source) and listener (receiver), drops the level of the sound by approximately 6 dB. Sound pressure levels are not directly additive, however, but must first be expressed as mean square pressures before adding (Berglund & Lindvall 1995). The equation is as follows: SPL = 10 loglo [10SP1,1110 + ioSPL2iio + .... + loSPLXnoi For example, if two sound sources have SPLs of 80 dB and 90 dB, then the resulting sound pressure is 90.4 dB. Adding two sounds with the same SPL, for example 90 dB, increases the total SPL by 3 dB, to 93 dB. a. Loudness Description Sound pressure level, however, does not completely describe loudness, which is a subjective perception of sound intensity. Loudness increases with intensity, but is also dependent on frequency. Thus the human ear may not perceive a six dB increase as twice as loud. In general, people are more sensitive to sounds in the middle of the range of hearing, from around 200 Hz to 5000 Hz. Fletcher and Munson (1933) first established the 1000 -Hz tone as the standard sound against which other tones would be judged for loudness. Later, Stevens (1955) proposed that the unit of loudness be termed the sone, and that one sone be ascribed to a 1000 -Hz tone set at a SPL 7Other units used to represent an equivalent sound pressure include 0.0002 ,ubar, 0.0002 dyne /cm2, and 20 ,uN /m2. 27 of 40 dB under specified listening conditions. On the sone scale, a sound twice as loud as one sone would be two cones, four times as loud would be four sones, and so on. Equal loudness contours, identified in units of phons, demonstrate how the SPL, in dB, of a tone must be varied to maintain the perception of constant loudness. Ideally, sound measurement meters would give a reading equal to loudness in phons, but because phons are based on human perception, and perception process will vary from individual to individual, this has not been practical until recently (Berglund & Lindvall 1995). Loudness is still measured in decibels, however, following past practices. Various filters have been devised to approximate the frequency characteristics of the human ear, by weighting sound pressure level measurements as a function of frequency. Several weighting systems have been developed, but the one in most common use is the A- weighted filter, with sound pressure levels commonly expressed as dBA. Loudness levels range from about 20 dB (24 -hr average) in very quiet rural areas, to between 50 and 70 dB during the daytime in cities. Additional examples of typical loudness measures are illustrated in Figure 1. Perceived Sound Level Sound Level Examples Leaf Blower Reference Fig. I. Comparison of sound levels in the environment dB= decibels pPa= micro Pascals dB µPa 160 2x108 fireworks at 3 feet • • 50 r t ' jet at takeoff 140 2X108 threshold of pain : 38 t " power drill _ 120 2x107 thunder • ® " s,f auto horn at 1 meter 100 i 2x106 snowmobile 90 diesel truck, food blender a r • ly 80 2X105 garbage disposal 70 j vacuum cleaner v ©DF113�p►i1Ll( 60 2x104 ordinary conversation s� 50 t .. .; average home 40 2x103 library QUIET t quiet conversation VERY QUIET 20 2x102 soft whisper 10 rustling leaves BARELY AUDIBLE 0 2x101 threshold of hearing Fig. I. Comparison of sound levels in the environment dB= decibels pPa= micro Pascals b. Sound Level Measurement The ANSI B 175 Accredited Standard Committee, a group that includes government officials, Underwriters Laboratories, leaf blower manufacturers, and trade associations, and which is accredited by the American National Standards Institute, Inc. (ANSI), developed a method for measuring the sound levels from leaf blowers (Appendix F). The purpose of the standard method is to establish sound level labeling requirements for leaf blowers applicable to noise received by bystanders. The standard also includes requirements for safety precautions to be included in manuals for use by operators. The ANSI standard specifies a test area in a field in which natural ground cover does not exceed three inches in height and which is free of any large reflecting surfaces for a minimum of 100 ft from the blower. The sound level meter must be set for slow response and the A- weighting network. Once the blower is adjusted and running properly, the receiver (microphone) is set up 50 ft from the operator and 4 ft above ground. Sound level readings are taken in a circle every 45 degrees for a total of eight readings, as either the operator rotates or the microphone is moved. The eight readings are then averaged and reported to the nearest decibel. In wide use, the method has been criticized as sometimes generating unreproducible results. Typical comments expressed in meetings with ARB staff were to the effect that the manufacturer- reported sound levels for leaf blowers can be significantly different than those obtained by some third party testers. The standard has been revised (Dunaway 1999) and approved February 11, 2000, which may address the issue of reproducibility. Other comments about the method criticize the fundamental requirements for testing in an open field, with no reflecting surface for 100 ft, and the receiver 50 ft away, as being unrealistic and unrepresentative of real -world use on residential properties (Allen 1999a). A standardized method, however, usually does not reflect real -world conditions, but rather is useful for comparing sound levels from different blowers tested under the same conditions. The complexity and precision required by the method does appear to render it unsuitable as a field enforcement standard (Zwerling 1999). While the ANSI method yields sound level exposures for a bystander, the noise level exposure for the operator is measured using an audiodosimeter. For occupational exposures, a dosimeter can report the noise dose as a percentage relative to the permissible exposure level of 90 dBA (8 CCR General Industry Safety Orders, Article 105, Appendix A; 29 CFR 1910.25). The eight -hour time- weighted- average sound level experienced by the worker is then calculated fiom the dose, using a formula specified in regulations. Additional details can be found in the OSHA and Cal/OSHA Technical Manuals.g 80SHA's Technical Manual is available on then website (www.osha.gov) and noise measurement is in Section III, Chapter 5. Cal/OSHA'S manual is available from Cal/OSHA. WE 3. Noise in California a. Noise Sources By all accounts, noise exposure is increasing both as the number of sources increases and as existing sources get noisier (Berglund & Lindvall 1995). We drive our cars more and take more airplane trips, increasing noise from what have been the two major sources of noise for at least the last two decades; sales of engine - powered lawn and garden equipment continue to increase; and movie theaters and video arcades use noise to increase excitement (Consumer Reports 1999, PPEMA 1999, U.S. EPA 1981). The major sources of noise are transportation, from road, air, and rail traffic, which impact the most people of all noise sources; industrial machinery and facilities; construction; building services and maintenance activities; domestic noise from one's neighbors; and self - inflicted noise fiorn leisure activities, which may quality as domestic noise to one's neighbors (Berglund & Lindvall 1995). b. Numbers of People Potentially posed: the Public It is not possible to state with any certainty how many people in California are exposed to noise from leaf blowers. Indeed, the most recent nationwide estimate of the number of people exposed to noise from various sources dates from 1981. In that study, the U.S. EPA estimated that 730,000 people were exposed to noise from leaf blowers above the day -night average sound level of 45 dBA (U.S. EPA 1981). The use of leaf blowers has grown tremendously since 1980, however, and thus these numbers cannot be reliably scaled for an estimate of the number of Californians exposed to leaf blower noise today. As California's population has grown almost 41% since 1970 (CDF 1998, CDF 1999), population density, and thus noise exposure, has increased. California classifies counties as being metropolitan or non - metropolitan, based on the Bureau of the Census categorization of standard metropolitan statistical areas as containing or being close to a large city. As of January 1, 1999, the thirty -four metropolitan counties comprise 96.7% of California's population, or about 32.67 million people. The population of Californians who live in non - metropolitan counties, while small at 3.3% of the total, or 1.11 million people, has increased faster than the population in metropolitan counties (47.1 % increase versus 40.5% increase, 1970 -1999) and thus even noise exposures in the lowest populated counties have likely increased over the past thirty years. Unfortunately, without a comprehensive and current survey of noise exposures in California, it is not possible to determine, from available data, how many Californians are exposed to noise, and in particular exposed to noise from leaf blowers. The only conclusion is that the number of people affected by noise is likely increasing as population density increases even in non- metropolitan areas of the state. How many people are exposed to, and annoyed by, noise from leaf blowers is a question for future research. 30 c. Numbers of People Potentially Exposed: the Operator In southern California, about 80% of lawn and landscape contracting firms use leaf blowers (Anon 1999), thus one can assume that most gardeners are exposed to the noise from leaf blowers, either as an operator or from working in close proximity to the operator. From the California database of employees covered by unemployment insurance, in the fourth quarter of 1998 there were 59,489 workers reported by 6790 firms, in the SIC Code 0782, Lawn and Garden Services (M. Rippey, pers. com). This number is assumed to be the lower bound of those exposed, as there are an unknown number of self - employed gardeners, who may not report their earnings or be covered by unemployment insurance. Future research could test the hypothesis that all lawn and garden service workers are exposed, as operators or from working in close proximity, to the noise from leaf blowers. 4. Regulating Noise a. Federal Law The Noise Control Act of 1972 established a statutory mandated national policy "to promote an environment for all Americans free from noise that jeopardizes their public health and welfare." The Office of Noise Abatement and Control was established within the U.S. EPA to carry out the mandates of the Noise Control Act. The Office of Noise Abatement and Control published public health and welfare criteria; sponsored an international conference; examined dose - response relationships for noise and its effects; identified safe levels of noise; promulgated noise regulations; funded research; and assisted state and local offices of noise control; until funding for the office was removed in 1981 -1982 (Suter 1991; Shapiro 1991). In its almost ten years of operation, U.S. EPA produced several documents that are still relevant and were consulted from this report. The hearing of workers is protected by regulations promulgated under the Occupational Safety and Health Act of 1970. As California employers fall under California's equivalent program, hearing protection law will be covered below understate law. b. State Law California enacted the Noise Control Act of 1973 to "establish a means for effective coordination of state activities in noise control and to take such action as will be necessary..." [HSC 46000(g)]; the office was established within the California Department of Health Services. One of the primary functions of the office was to provide assistance to local governmental entities that develop and implement noise abatement procedures, and several guidelines were written. Funding for the office, however, ended beginning in the 1993 -1994 fiscal year; no relevant reports or guidelines were located for this report. California's counterpart to OSHA, the Cal/OSHA, has a General Industry Safety Order [8 CCR Article 105 5095 -5100] for the control of noise exposure that is very similar to the federal 31 OSHA regulations. When sound level exposure exceeds 85 dBA for an 8 -hour time - weighted average, employers are required to provide a hearing conservation program at no cost to employees. The hearing conservation program includes audiometric testing of hearing, provision of hearing protectors, training, and record keeping. Employers are required to provide employees with hearing protection when noise exposure exceeds 90 dBA in an eight -hour work day; as noise levels increase, the allowable exposure duration also decreases. The permitted duration for an employee exposed to 103 dBA, for example, is one hour and nineteen minutes in a work day [8 CCR 5096 (a)(b)]. Employers are allowed to use personal protective equipment to reduce sound level exposures if administrative or engineering controls are not feasible or fail to reduce sound levels within permissible levels. c. Local Ordinances In contrast to the low level of activity on noise control at the federal and state levels, local California cities and counties have been very active in regulating and enforcing noise standards. About twenty cities have banned the use of gasoline- powered, or gasoline- and electric - powered leaf blowers, from use within their city limits (City of Palo Alto 1999a). Including the recent Los Angeles ban on use within 500 ft of residences, about 13 %0 of Californians live in cities that ban the use of leaf blowers, and six of the ten largest California cities have ordinances that restrict or ban leaf blowers. All together, about one hundred California cities have ordinances that restrict either leaf blowers specifically or all gardening equipment generally, including the cities with bans on leaf blower use (IME 1999). The restrictions on leaf blowers fall into four basic categories, with many cities employing a combination of approaches: time of day /day of week, noise levels, specific areas, and educational (City of Palo Alto 1999a). Time of day /day of week ordinances are the most common and are used to control when leaf blowers can be operated. Typically, hours of use are restricted to times between 7:00 a.m. and 7:00 p.m., and days of use are either Monday through Friday or Monday through Saturday, and sometimes including Sunday, with shorter hours on the weekend, based on the assumption that leaf blower noise is most offensive during the evening and night time hours, and on the weekend. There may be exceptions for homeowners doing their own yard work and for work in commercial areas. Time of day /day of week ordinances are relatively easy to enforce. A problem with these ordinances, however, is that they ignore the needs for quiet during the day of babies, young children, and their caretakers; day- sleepers; the ill; the retired; and a growing population of those who work in a home office. Some cities regulate leaf blower use based on noise levels recorded at a specified distance from the operator. Palos Verdes Estates and Davis, for example, set the noise level at 70 dBA at 50 ft, and Newport Beach and San Diego have a 65 dBA at 50 ft restriction. Davis allows single - family homeowners to avoid the restriction if the leaf blower is operated for less than ten minutes. Palos Verdes Estates requires blowers to be tested and certified by the city. Otherwise, a noise level restriction is very difficult to enforce as the enforcement officer must be trained in the use of sound level meters, carry the meter, and record the sound level before the operator turns off the 32 leaf blower or moves on. These rules target the control of noise from blowers, and could protect those who are home during the day, if they could be effectively enforced. Recognizing that leaf blowers are often perceived as most offensive when used in residential areas, many cities stipulate usage restrictions only in residential areas, or within a certain distance of residential areas. The residential use distance restrictions prohibiting the use of leaf blowers range from 100 ft, in Foster City, to 500 ft, in Los Angeles. This type of ordinance protects those who are at home and in need of quiet during the day, but does not address issues of those who work and recreate in commercial or other non - residential areas. Cities sometimes couple area restrictions with user guidelines, such as prohibitions on blowing debris onto adjacent properties, and require operators be educated on the proper use of leaf blowers so as to minimize noise levels and environmental issues. These educational approaches are generally not oriented towards enforcement, but seek to change operator behavior. Educational -approaches are often endorsed by landscapers and manufacturers, who believe that much of the discord over leaf blower usage originates with the few gardeners who use them incorrectly or inconsiderately. For example, an organization calling itself LINK, or Landscapers Involved With Neighborhoods and Kids, promotes educating operators to use their leaf blowers at half - throttle within 150 ft of homes (LINK 1999). 5. Noise From Leaf Blowers In a survey of Southern Californian gardeners by a consumer products manufacturer (Anon 1999), the top two ranked attributes of a desirable leaf blower were, in order, "powerful" and "quiet." Important features were identified as "backpack mounted," "noise below legal limits," and "variable speed." When asked what they dislike about their leaf blowers, the most commonly cited problem was "noise." Taken together, these answers suggest that loud noise from leaf blowers is not only an issue for the public, but is also a major issue of concern for the gardeners who use them, at least in Southern California. On the other hand, a major manufacturer has indicated that low noise does not even show up in their survey of desirable leaf blower features (Will 1999b), so perhaps low noise is only a concern of California gardeners. a. Bystander noise exposure Manufacturer - reported noise levels from leaf blowers are summarized in Appendix G; all reported noise levels are assumed to represent bystander exposure, with the receiver 50 ft from the blower, unless otherwise noted. The reported levels are based on statements in promotional literature or personal communications with manufacturers; some manufacturers did not report the sound levels of most of their models in materials available to the ARB. For backpack and hand held blowers, sound levels range from 62 dBA to 75 dBA, with more than half registering between 69 and 70 dBA (Figure 2). Bearing in mind the logarithmic decibel scale, the difference in a leaf blower at 62 dBA and one at 75 dBA, a 13 dBA range, represents more than a quadrupling of the sound pressure level, and would be perceived by a listener as two to three 33 tunes as loud. The rule of thumb is that when a sound level increases by ten dB, the subjective perception is that loudness has doubled (MPCA 1987). Fig. 2. Loudness Levels of Leaf Blowers (50 ft) 20 N 0 15 0 10 0 as .c E 5 z 0 62 63 64 65 66 67 68 69 70 71 72 73 74 75 Loudness (dB) There are presently two gasoline- powered backpack and three hand held electric leaf blowers that are reported by their manufacturers to be very quiet. Maruyama and Toro have the two quietest backpack blowers, and Poulan/Weedeater, Stihl, and Toro have produced the quietest hand held blowers. Echo, Inc., which sells slightly under one -third of the total number of backpack blowers, has a model rated at 65 dB, the PB -46LN. In 1996, the most popular Echo backpack leaf blower, based on sales, was the Echo PB -400E, which is also one of the noisiest at 74 dBA. By 1999, however, the quieter PB -46LN had surpassed the PB -400E in sales (Will, L., pers. com.). b. Operator Noise Exposure Data on noise levels at the leaf blower operator, s ear are limited. The League for the Hard of Hearing (1999) publishes a fact sheet in which the noise level of a leaf blower is listed as 110 dBA. Clark (1991) reported that one model by Weedeater emitted a maximum level of 110- 112 dBA and an equivalent A- weighted sound level (L ,q) of 103.6 dBA. This leaf blower model, however, is no longer available and these data may not be comparable to today's leaf blowers. Other than Clark's report, no other published report could be located, but unpublished data were found. Schulze and Lucchesi (1997), in an unpublished conference presentation, reported the range and average sound pressure level from four leaf blowers. The four leaf blowers were 34 unidentified models from Craftsman, Weedeater, and Shop Vac.9 The authors reported that 3 ft from the leaf blower the sound pressure levels ranged from 80 to 96 dBA, with an average value of 88 dBA, and concluded that leaf blower noise did not violate the OSHA permissible noise exposure limit. Sound pressure levels, however, were not measured at the operator's ear, and thus usefulness of the data is limited. In addition, whether or not the OSHA noise exposure limits are violated depends on the amount of time the listener is exposed, as the action level is an eight -hour time- weighted average. At least one of the leaf blowers had an SPL above the Permissible Exposure Limit of 90; at 96 dBA, the operator would be restricted to a 3 hr, 29. minute daily exposure without hearing protection. The Portable Power Equipment Manufacturers Association (Hall 1999) conveyed limited, blinded data to the ARB on operator exposures. With no information as to data collection methods (some pages were marked "ISO 7182 "), manufacturers, models, or maximum and minimum sound levels, these data are of limited quality. Reported operator sound levels, some of which were identified as "full open throttle" or "full load," ranged from 91.5 dBA to 106 dBA. A consultant with James, Anderson & Associates, Inc. (Hager 1999), provided ARB with data collected as a part of comprehensive noise exposure studies by the firm (Table 7). As with the PPEMA data, ARB was not given the make or models of leaf blowers tested. Sound levels were recorded in the hearing zone of groundskeepers while they were operating leaf blowers, along with the amount of time the groundskeeper operated the leaf blower in an 8 -hr day. Sound levels were measured in dBA per federal OSHA requirements. As shown, duration of use ranged from 15 minutes to 7.6 hours (average 2.1 hr) during the day. Operator exposure ranged from 88.6 to 101.3 dBA. In this data set, only one of the six individuals monitored would have exceeded the protective levels, based on leaf blower use for 7.6 hrs. blower. 9ARB was not able to obtain the specific models tested or actual SPLs for each model leaf 35 Table 7. Leaf Blower Operator Noise Exposures and Duration of Use (MHaga r 1999 Average SPL, dBA Minimum SPL, dBA Maximum SPL, dBA Duration of Leaf Blower use hr 99.5 96.4 101.3 0.75 92.0 N/R N/R 1.0 101.2 N/R 101.9 2.3 101.3 98.3 105.7 7.6 95.9 92.0 97.0 0.25 88.6 85.0 90.4 0.5 N/R = not reported Eric Zwerling of the Rutgers Noise Technical Assistance Center, along with Les Blomberg, Executive Director of the Noise Pollution Clearinghouse, recently conducted studies of operator exposure and the sound quality of leaf blowers (Zwerling 1999). While the data are still being analyzed, preliminary results were made available to the ARB. Three backpack and one handheld leaf blowers were tested using ANSI B 175.2 -1996 test method for the bystander exposure and using personal dosimetry for operator exposures (Table 8). All equipment used for tests was certified and calibrated. Zwerling and Blomberg used a 3 dB exchange rate for the operator dosimetry, as recommended by NIOSH, but noted that the data can be reasonably compared to data derived with the OSHA mandated 5 dB exchange rate because of the steady sound emissions of the leaf blowers. Because of this, the OSHA permissible exposure durations, which are based on the 5 dB exchange rate, are noted in Table 8. The difference is most important for the worker, who is allowed, for example, a 1 hr exposure (unprotected) at 105 dB by OSHA, but only 4 min, 43 sec exposure (unprotected) under the more conservative NIOSH- recommended 3 dB exchange rate. 79n Table 8. Sound Levels of Some Leaf Blowers, E. Zwerling & L. Blomberg *Samples ranged from 5 -10 minutes; each reported value is a distinct sample. The microphone was attached to the cap above the operator's ear. Finally, the Echo Power Blower Operator's Manual advises operators to wear hearing protection whenever the unit is used. The user is instructed that "OSHA requires the use of hearing protection if this unit is used 2 hours per day or more." This statement indicates that the operator may be exposed to an SPL of 100 dBA or more during use. 6. Use of Hearing Protectors and Other Personal Protection Gear When this study was initiated, there were no studies found that documented the incidence of personal protective equipment usage among operators of leaf blowers. Hearing protectors are widely available, and some manufacturers provide an inexpensive foam ear plug set with the purchase. More expensive custom molded ear plugs and ear muffs provide better protection than the moldable foam ear plugs, but again no data were available on usage. Two studies did examine the incidence of usage of hearing protection in other industries. In one study of 524 industrial workers, although 80.5% were provided with hearing protection devices, only 5.1 % wore them regularly (Maisarah & Said 1993). In another study of metal assembly workers who worked in a plant where the average noise level was 89 dBA, only 39% of the men reported wearing hearing protection always or almost always (Talbott et al. 1990). By the end of September 1999, however, three studies were delivered to the ARB that included information on the use of hearing protection by leaf blower operators. Two of the studies consisted of direct observations of operators; the third was a survey that asked people who hire gardeners to recall the use of personal protection gear by their gardeners. Following are summaries of each of the studies. 37 OSHA Permissible Bystander Operator Exposure Exposure, Exposure,* Duration MakelModel Type Condition dB Leq (approx) Stihl BR 400 Backpack New 73.89 105.7, 105.8, 52 min 105.5 Stihl BR 400 Backpack Used 74.5, 74.63 103.3, 102.9 1 hr, 19 min Kioritz DM9 Backpack Used 76.0 102.0 1 hr, 31 min Stihl BR 75 Handheld New 68.4 98.4, 97.9 2 lrr, 38 min *Samples ranged from 5 -10 minutes; each reported value is a distinct sample. The microphone was attached to the cap above the operator's ear. Finally, the Echo Power Blower Operator's Manual advises operators to wear hearing protection whenever the unit is used. The user is instructed that "OSHA requires the use of hearing protection if this unit is used 2 hours per day or more." This statement indicates that the operator may be exposed to an SPL of 100 dBA or more during use. 6. Use of Hearing Protectors and Other Personal Protection Gear When this study was initiated, there were no studies found that documented the incidence of personal protective equipment usage among operators of leaf blowers. Hearing protectors are widely available, and some manufacturers provide an inexpensive foam ear plug set with the purchase. More expensive custom molded ear plugs and ear muffs provide better protection than the moldable foam ear plugs, but again no data were available on usage. Two studies did examine the incidence of usage of hearing protection in other industries. In one study of 524 industrial workers, although 80.5% were provided with hearing protection devices, only 5.1 % wore them regularly (Maisarah & Said 1993). In another study of metal assembly workers who worked in a plant where the average noise level was 89 dBA, only 39% of the men reported wearing hearing protection always or almost always (Talbott et al. 1990). By the end of September 1999, however, three studies were delivered to the ARB that included information on the use of hearing protection by leaf blower operators. Two of the studies consisted of direct observations of operators; the third was a survey that asked people who hire gardeners to recall the use of personal protection gear by their gardeners. Following are summaries of each of the studies. 37 a. Zero Air Pollution Study (1 99) The goal of this study was to `observe 100 yard maintenance workers to determine the percentage of workers who followed the safety instruction while operating gas powered leaf blowers. Workers were observed from August to October, 1997 in the western portions of the City of Los Angeles, including the San Fernando Valley. Of 100 leaf blower operators observed, none wore hearing protection, one (1 %) wore breathing protection (dust mask), and 22 (22 %) wore eye protection of some kind. Of the workers observed, 27 (27 %) were interviewed; seven of those claimed hearing impairment as a result of using leaf blowers and two claimed to have breathing problems which they attributed to using leaf blowers. Ten of those interviewed (37 %) said they were aware of manufacturers' safety instruction but did not feel it was necessary to follow the instructions. The remaining 17 (63 %) were unaware of manufacturers' safety instructions. b. Citizens for a (quieter Sacramento Study (1999b) The goal of this study, as for the Zero Air Pollution study, was to determine the percentage of leaf blower operators who wear personal protective equipment when using blowers. A total of 64 observations were made during August and September 1999; 12 in Sacramento, 47 in the Los Angeles area, and 5 in other cities. Most (88 %) of the observations were of blowers being used on residential properties. Of the 64 observations, there were four (6 %) individuals observed wearing hearing protection, 41 (64 %) were not wearing hearing protection, and in the remaining cases the observer could not tell whether or not hearing protection was used. Eye protection use was lower, only 3 (5 %) operators were wearing glasses, but breathing protection incidence was higher, seven (11 %) wore dusk masks. Observations were also made of the incidence of personal protection of other workers, when the crew was larger than one person. Of the 38 observations of other workers, two (5 %) were using hearing protection, two (5 %) were using eye protection, and two (5 %) wore dusk masks. c. Surve, 9y 9 Report (Wolfberg g 999) The third study provided to the ARB was authored by Mrs. Diane Wolfberg, Chair of the Zero Air Pollution Education Committee and Mr. George Wolfberg. Although the authors are members of Zero Air Pollution, the study was distinct from the 1997 study summarized above. The goal of this study was to determine "opinions and perceptions of California residents regarding the use of leaf blowers ... for residential landscape maintenance." Mainly residents of Los Angeles were surveyed. Survey takers asked residents a variety of questions related to the use of leaf blowers on residential properties; in addition, respondents were asked about the incidence of personal protective equipment use by leaf blower operators. Because the data are based on recall rather than direct observations, their usefulness is limited. Data are summarized here, nevertheless, for completeness. Of respondents who have had leaf blowers used on their properties in the previous 12 months, 53% reported that leaf blower operators never use a face mask, 62% never use eye protection, and 69% never wear hearing protection. On the positive side, however, respondents reported that 13 % of operators always wear a face mask, 19% always wear eye protection, and 9% always wear hearing protection. These percentages are much higher than found in the two direct observation studies. 7. Sound Quality As discussed earlier, the perceived loudness of noise is dependent on both sound pressure level and frequency, which is termed the sound quality. One study examined sound quality from leaf blowers (Zwerling 1999). While this study is unpublished and data are still being analyzed, the authors have made data and preliminary fmdings available to the ARB. Figures 3 and 4 illustrate sample sound spectra from a leaf blower and ambient sound, respectively. As shown in Figure 3, the sound spectrum of the gasoline- powered leaf blower contains a significant amount of high intensity and high frequency emissions. In a quiet residential neighborhood (Figure 4), there are few or no natural sources of sound at these high frequencies. Therefore, the sound emissions of gasoline- powered leaf blowers are not only more intense than the ambient sound levels, their spectra are noticeably different than the spectrum for ambient sounds. The high frequency emissions are, therefore, not masked by other sounds and are more noticeable, perhaps accounting for the high level of annoyance reported by bystanders. These data and their implications for annoyance should be confirmed by further study. 80.0 70.0 60.0 Co 50.0 40.0 30.0 Fig. 3. Sound Quality Spectrum of a Representative Leaf Blower Stihl BR -400 1/3 Octave Spectrum 12 25 50 100 200 400 800 1k6 3k15 6k3 12k5 Hertz 39 80.0 70.0 60.0 m 50.0 40.0 30.0 Fig. 4. Sound Quality Spectrum of a Representative Neighborhood 1/3 Octave Spectrum 12 25 50 100 200 400 800 1k6 3k15 6k3 12k5 Hertz 8. Summary Noise is the general term for any loud, unmusical, disagreeable, or unwanted sound, which has the potential of causing hearing loss and other adverse health impacts. While millions of Californians are likely exposed to noise from leaf blowers as bystanders, given the ubiquity of their use and the increasing density of California cities and towns, there is presently no way of knowing for certain how many are actually exposed, because of the lack of studies. In contrast, it is likely that at least 60,000 lawn and garden workers are daily exposed to the noise from leaf blowers. Many gardeners and landscapers in souther California are aware that noise is an issue and apparently would prefer quieter leaf blowers. Purchases of quieter leaf blowers, based on manufacturer data, are increasing. While little data exist on the noise dose received on an 8 -hr tune - weighted- average by operators of leaf blowers, data indicate that some operators may be exposed above the OSHA permissible exposure limit. It is unlikely that more than 10% of leaf blower operators, and probably a much lower percentage, regularly wear hearing protective gear, thus exposing them to an increased risk of hearing loss. The sound quality of gasoline- powered leaf blowers may account for the high level of annoyance reported by bystanders. :1 III. REVIEW OF HEALTH EFFECTS Leaf blower noise, exhaust and fugitive dust emissions, as discussed in previous sections of this report, are health concerns. The goal of this section is to present information on health effects of identified hazards from leaf blowers; this section does not present exposure information or data tying identified hazards to specific health effects in leaf blower operators or bystanders. The following discussion addresses the health effects of particulate matter, carbon monoxide, unburned fuel, and noise. Particulate matter, carbon monoxide, and unburned fuel are components of exhaust emissions; particulate matter is also the major constituent of fugitive dust. Ozone is a pollutant that is formed in the atmosphere through chemical reactions of hydrocarbons (unburned fuel) and nitrogen oxides in the presence of ultraviolet light. Although not directly emitted, ozone is a pollutant of concern because leaf blowers emit hydrocarbons, which react to form ozone. The health effects of nitrogen oxides_are not discussed as these emissions from leaf blowers are relatively low, and any health effects would be negligible. National Ambient Air Quality Standards have been set by the federal government to protect public health and welfare. In addition, California has State ambient air quality standards. These standards include a margin of safety to protect the population from adverse effects of chronic pollutant exposure. The National Ambient Air Quality Standards and California standards are intended to protect certain sensitive and probable risk groups of the general population (Appendix C). A. Particulate Matter Fugitive dust is not a single pollutant, but rather is a mixture of many subclasses of pollutants, collectively termed particulate matter (PM), each containing many different chemical species (U.S. EPA 1996). Particles of 10 /gym and smaller are inhalable and able to deposit and remain on airway surfaces. The smaller particles (2.5 gm or less) are able to penetrate deep into the lungs and move into intercellular spaces. The respirable particles owe their negative health impacts, in part, to their long residence time in the lung, which allows chemicals time to interact with body tissues. ARB staff could not locate data on the specific chemical and physical make -up of leaf blower dust, although some data are available on paved road dust, thus only generic effects from the respirable fraction (particles 10 gm and smaller) are addressed. Many epidemiological studies have shown statistically significant associations of ambient PM levels with a variety of negative human health endpoints, including mortality, hospital admissions, respiratory symptoms and illness measured in community surveys, and changes in pulmonary mechanical function. Associations of both short-term, usually days, and long -term, usually years, PM exposure with most of these endpoints have been consistently observed. Thus, the public health community has a great deal of confidence that PM is significantly associated with negative health outcomes, based on the findings of many studies. 41 There remains uncertainty, however, regarding the magnitude and variability of risk estimates for PM. Additional areas of tuncertainty include the ability to attribute observed health effects to specific PM constituents, the time intervals over which PM health effects are manifested, the extent to which findings in one location can be generalized to other locations, and the nature and magnitude of the overall public health risk imposed by ambient PM exposure. While the existing epidemiology data provide support for the associations mentioned above, understanding of underlying biologic mechanisms is incomplete (U.S. EPA 1996). B. Carbon Monoxide A component of exhaust, carbon monoxide (CO) is a colorless, tasteless, odorless, and nonirritating gas that is a product of incomplete combustion of carbon - containing fuels. With exposure to CO, subtle health effects can begin to occur, and exposure to very high levels can result in death. The public health significance of CO in the air largely results from CO being absorbed readily from the lungs into the bloodstream, forming a slowly reversible complex with hemoglobin, known as carboxyhemoglobin. The presence of significant levels of carboxyhemoglobin in the blood reduces availability of oxygen to body tissues (U.S. EPA 1999b). Symptoms of acute CO poisoning cover a wide range depending on severity of exposure, from headache, dizziness, weakness, and nausea, to vomiting, disorientation, confusion, collapse, coma, and at very high concentrations, death. At lower doses, central nervous system effects, such as decreases in hand -eye coordination and in attention or vigilance in healthy individuals, have been noted (Horvath et al. 1971, Fodor and Winneki 1972, Putz et al. 1976, 1979, as cited in U.S. EPA 1999b). These neurological effects can develop up to three weeks after exposure and can be especially serious in children. National Ambient Air Quality Standards have been set to protect public health and welfare and are intended to protect certain sensitive and probable risk groups of the general population. The sensitive-and probable risk groups for CO include anemics, the elderly, pregnant women, fetuses, young infants, and those suffering from certain blood, cardiovascular, or respiratory diseases. People currently thought to be at greatest risk from exposure to ambient CO levels are those with ischemic heart disease who have stable exercise - induced angina pectoris (cardiac chest pain) (ARB 1992, U.S. EPA 1999b). In one study, high short-term exposures to CO were found in people operating small gas - powered garden equipment (ARB 1992). C. Unburned Fuel Some toxic compounds are present in gasoline and are emitted to the air when gasoline evaporates or passes through the engine as unburned fuel (ARB 1997). Benzene, for example, is a component of gasoline. Benzene is a human carcinogen and central nervous system depressant. The major sources of benzene emissions in the atmosphere are from both unburned and burned gasoline. The amount of benzene in gasoline has been reduced in recent years through the 42 mandated use of California Reformulated Gasoline (ARB undated fact sheet10). Other toxic compounds that are emitted from vehicle exhaust include formaldehyde, acetaldehyde, and 1,3- butadiene. Acetaldehyde is a probable human carcinogen (Group 132) and acute exposures lead to eye, skin, and respiratory tract irritation. 1,3- Butadiene is classified as a probable human carcinogen, is mildly irritating to the eyes and mucous membranes, and can cause neurological effects at very high levels. Formaldehyde is highly irritating to the eyes and respiratory tract and can induce or exacerbate asthma. It is classified as a probable human carcinogen (Group B1). D. Ozone Ozone is a colorless, odorless gas and is the chief component of urban smog. It is by far the state's most persistent and widespread air quality problem. Ozone is formed from the chemical reactions of hydrocarbons and nitrogen dioxide in the presence of sunlight. Leaf blowers emit substantial quantities of hydrocarbons, primarily from unburned fuel, which can react to form ozone. Ozone is a strong irritant and short-term exposures over an hour or two can cause constriction of the airways, coughing, sore throat, and shortness of breath. Ozone exposure may aggravate or worsen existing respiratory diseases, such as emphysema, bronchitis, and asthma. Chronic exposure to ozone can damage deep portions of the lung even after symptoms, such as coughing, disappear. Over time, permanent damage can occur in the lung, leading to reduced lung capacity. E. Noise The literature on health effects of noise is extensive. Exposure of adults to excessive noise results in noise - induced hearing loss that shows a dose - response relationship between its incidence, the intensity of exposure, and duration of exposure. Noise - induced stimulation of the autonomic nervous system reportedly results in high blood pressure and cardiovascular disease (AAP 1997). In addition there are psychological effects. The following subsections will first discuss noise - induced hearing loss and physiological stress- related effects. Adverse impacts on sleep and communication, effects of performance and behavior, annoyance, and effects on wildlife and farm animals are also described. These are not perfect divisions between discreet affects: nighttime noises can cause sleep - deprivation, for example, which can lead to stress, elevated blood pressure, and behavioral changes, especially if the effect is repeated and uncontrollable.-But first, before discussing effects, the reader should have an understanding of how the car functions. 'Ohttp://arbis.arb.ca.gov/cbg/pub/cbgbkgri.litm 43 1. Hearing and the Ear A detailed discussion of the ear's anatomy and the mechanism by which we hear is beyond the scope of this report, but a basic level of understanding is necessary so that later discussions of damage to hearing will be better understood. For further information, the reader is referred to any basic acoustics or biology text. The ears are paired sensory organs that serve two functions, to detect sound and to maintain equilibrium; only sound detection will be addressed in this report. The ears are composed of the external ear, middle ear, and the inner ear. With the assistance of the external ear in collecting and focusing sound, vibrations are transmitted to the middle ear via the ear canal and the eardrum. The vibrations of the eardrum are transmitted by the bones of the middle ear to the fluid - filled sensory organ of the inner ear, the cochlea. As the fluid of the inner ear vibrates, the hair cells located in the cochlea bend, stimulating sensory receptors, and leading to nerve impulses being transmitted to the brain via the auditory nerve. The greater the hair cell displacement, the more sensory receptors and neurons are stimulated, resulting in the perception of an increase in sound intensity. Hearing loss can result from damage or growths in any portion of the ear and the part of the brain that processes the nerve impulses. Damage to the outer and middle ear result in conductive hearing loss, in which case the vibrations can still be perceived and processed if they can be transmitted by another means to the inner ear. Damage to the inner ear and auditory nerve result in sensorineural hearing loss. Sensorineural hearing loss can be temporary, if the body's mechanisms can repair the damage, but cumulative inner ear damage will result in permanent hearing loss. Aging, diseases, certain medications, and noise cause the majority of sensorineural hearing loss, which is not reversible by surgery or medication, and is only partially restored by hearing aids. 2. Noise - Induced Hearing Loss Roughly 25% of all Americans aged 65 and older suffer from hearing loss. Contrary to common belief, hearing loss is not part of the natural aging process, but is caused by preventable, noise - induced wear and tear on the auditory system (Clark & Bohne 1999). Noise - induced hearing loss develops gradually over years and results from damage to the inner ear. Sensory cells within the cochlea are killed by exposure to excessive noise. These cells do not regenerate but are replaced with scar tissue. After weeks to years of excessive noise, the damage progresses to the point where hearing loss occurs in the high - frequency range and is detectable audiometrically; speech comprehension is not usually affected and so at this level hearing loss is goes unnoticed by the individual. Eventually, with continued exposure, the hearing loss spreads to the lower pitches necessary to understand speech. At this point, the impairment has proceeded to the level of a handicap and is quite noticeable. The damage is not reversible and is only poorly compensated for by hearing aids. .. There is considerable variability among individuals in susceptibility to hearing loss. Based on major field studies conducted in the late 1960s and early 1970s, the U.S. EPA suggested that a 24 -hour equivalent sound level of 70 dBA would protect 96% of the population, with a slight margin of safety, from a hearing loss of less than five dBA at 4000 Hz (U.S. EPA 1974). This 24- hour, year -round equivalent sound level is based on a forty-year work -place noise level exposure (250 working days per year) of 73 dBA for eight hours and 60 dBA for the remaining 16 hours. The National Institute for Occupational Safety and Health reviewed the recommended occupational noise standard recently ( NIOSH 1996) and reaffirmed its recommended exposure limit of 85 dBA for occupational noise exposure. The report concluded that the excess risk of developing occupational noise - induced hearing loss fora 40 -hr lifetime exposure at 85 dBA is 8 %. In comparison, the OSHA regulation [29 CFR 1910.95] allowing a 90 dBA permissible exposure limit results in a 25% excess risk of developing hearing loss. The OSHA regulation, however, has not been changed to reflect the recommendation of the National Institute for Occupational Safety and Health.- NIOSH also recommended changing the exchange rate, which is the increment of decibels that requires the halving or doubling of exposure time, from the OSHA mandated 5 dBA to 3 dBA. This would mean that if the worker was permitted to be exposed to 85 dBA unprotected for 8 hr, then a noise exposure level of 88 dBA would be limited to 4 hr per day. The 3 -dBA exchange rate is supported by acoustics theory, and by national and international consensus. OSHA, however, continues to mandate a 5 dBA exchange rate in its regulations. In addition, the American Academy of Pediatrics (1997) has asked the National Institute of Occupational Safety and Health to conduct research on exposure of the fetus to noise during pregnancy and recommends that the OSHA consider effects on the fetus when setting occupational noise standards. 3. Non - Auditory Physiological Response In addition to hearing loss, other physiologic and psychological responses resulting from noise have been noted and are termed non - auditory effects. Noise is assumed to act as a non- specific biological stressor, eliciting a "fight or flight" response that prepares the body for action (Suter 1991). Research has focused on effects of noise on blood pressure and changes in blood chemistry indicative of stress. Despite decades of research, however, the data on effects are inconclusive. While many studies have shown a positive correlation between hearing loss, as a surrogate for noise exposure, and high blood pressure, others have shown no correlation (Suter 1991; Kryter 1994). The National Institutes of Occupational Safety and Health (1996) has called for further research to define a dose - response relationship between noise and non - auditory effects, such as hypertension and psychological stress. 45 4. Interference with Communication The inability to communicate can degrade the quality of living directly, by disturbing social and work - related activities, and indirectly, by causing annoyance and stress. The U.S. EPA (1974), in developing its environmental noise levels, determined that prolonged interference with speech was inconsistent with public health and welfare. Noise that interferes with speech can cause effects ranging from slight irritation to a serious safety hazard (Suter 1991), and has been shown to reduce academic performance in children in noisy schools, as reviewed by Kryter (1994). The U.S. EPA, therefore, developed recommended noise levels that are aimed at preventing interference with speech and reduced academic performance. An outdoor yearly average day -night sound level of 55 dBA permits adequate speech communication at about 9 -10 ft, and also assures that outdoor noise levels will not cause indoor levels to exceed the recommended level of 45 dBA. 5. Interference with Sleep It is common experience that sound rouses sleepers. Noise that occurs when one is trying to sleep not only results in repeated awakenings and an inadequate amount of sleep, but is also annoying and can increase stress. Noise that is below the level that awakens, however, also changes the sleep cycle, reduces the amount of "rapid eye movement" sleep, increases body movements, causes cardiovascular responses, and can cause mood changes and performance decreases the next day (Suter 1991). The U.S. EPA recommended an indoor average yearly day - night level of 45 dBA, which translates into a night time average sound level of 35 dBA, to protect most people from sleep disturbance. An average sound level, however, does not adequately account for peak sound events that can awaken and disturb sleep. Continuous noise has a significantly smaller sleep disturbance effect than intermittent noise. Research has found that subjects in sleep laboratory experiments will gradually reduce the number of awakenings throughout the night in response to noise, but other physiological changes, including a momentary increase in heart rate, indicative of arousal do not change. The question is whether physiological arousal, short of awakening, has a negative health effect. While study results are inconclusive on this issue, it is clear that noise above a certain level, about 55 dBA Leg according to Kryter (1994), will awaken people, even after long periods of repeated exposures. Repeated awakenings reduce feelings of restedness and cause feelings of annoyance, leading to stress responses and associated health disorders. 6. Effects on Performance and Behavior The working hypothesis in this area has been that noise can cause adverse effects on task performance and behavior at work, in both occupational and non - occupational settings. Results of studies, however, have not always been as predicted. Sometimes noise actually improves performance, and sometimes there are no measurable differences in performance between noisy and quiet conditions (Suter 1991). Kryter (1994) concluded that masking by noise of other .o auditory signals is the only inherent auditory variable responsible for observed effects of noise on mental and psychomotor tasks. The effect of noise on "helping behavior" in the presence and absence of noise is more clear. Mathews and Canon (1975) tested the hypothesis that high noise levels may lead to inattention to the social cues that structure and guide interpersonal behavior. In a laboratory study in which subjects did not know they were being studied, they found that fewer persons were willing to help someone who had "accidentally" dropped materials when background noise levels were 85 dB than when they were 65 dB or 48 dB. In a subsequent field study, similar results were demonstrated with background noise from a lawn mower. Initially, subjects were tested as to their willingness to help a man who had dropped books and papers while walking from his car to a house; in this test, helping behavior was low both in ambient (50 dB) and high (87 dB) noise conditions. When the test was repeated with a cast on the arm of the man who dropped the books, helping behavior was high under ambient noise (80 %) and low under high noise (15 %) conditions. These and other studies lead to the conclusion (Suter 1991) that even moderate noise levels can increase anxiety, decrease the incidence of helping behavior, and increase the likelihood of hostile behavior. 7. Annoyance and Community Response Annoyance is a response to noise that has been extensively studied for years. Various U.S. government agencies began investigating the relationships between aircraft noise and its effect on people in the early 1950's. Annoyance is measured as an individual response to survey questions on various environmental factors, including as noise (Suter 1991). The consequences of noise- induced annoyance are privately held dissatisfaction, publicly expressed complaints, and possibly adverse health effects. Fidell et al. (1991) reviewed and synthesized the relationship between transportation noise and the prevalence of annoyance in communities based on over 30 studies. The relationship is an exponentially increasing function, with less than 10% of respondents reporting themselves to be highly annoyed at noises under an average day -night sound level of 56 dB. Fifty percent responded they were highly annoyed at sound levels approaching 79 dB, and nearly every person was highly annoyed at sound levels above 90 dB. Suter (199 1) concluded that throughout decades of study, community annoyance -has been positively correlated with noise exposure level, and that although variables such as ambient noise level, time of day, time of year, location, and socioeconomic status are important, the most important variable is the attitude of the affected residents. Kryter (1994) further elaborates that interference by noise, and the associated annoyance, depends on the activity of an individual when the noise event occurs, and the intensity and duration of the noise. People have different beliefs about noise, which are also important. Those most annoyed share similar beliefs that the noise may be dangerous, is probably preventable, are aware that non - auditory effects are associated with the noise source, state they are sensitive to noise, and believe that the economic benefit represented by the source is not important for the community (Fields 1990). 8. Effects of Noise on Animals 47 Kryter (1994) reviewed studies on the effects of noise both on wildlife and farm animals. None of these studies examine noise - induced hearing loss, but rather looked at effects of noise on litter size, prevalence of wildlife, and milk production. Most of the studies were conducted to examine the effects of airport noise, including noise from landings and takeoffs and sonic booms near commercial and military airports, and noise from construction activities during laying of pipelines across wilderness areas. Negative impacts on wildlife and farm animals, due to noise, were not supported by the studies. In the airport studies, the absence of human activities in the areas surrounding the high noise exposure zones appeared to be more important than noise, resulting in abundant wildlife. Fann animals exposed to frequent sonic booms showed little or no negative effects, again using such criteria as reproduction, milk production, and growth rate. No study, however, has examined the effects of leaf blower noise on animals. W. IV. POTENTIAL HEALTH AND ENVIRONMENTAL IMPACTS OF LEAF BLOWERS This section of the report synthesizes the information presented in the two previous sections, hazard identification and health effects, and characterizes the potential health impacts of leaf blowers on operators and bystanders. As discussed previously, there are no studies of the health impacts of leaf blowers, and essential information is missing that prevents ARB from preparing a quantitative risk characterization. There is, for example, no information on the , quantitative relationship between exposure to hazards from leaf blowers and adverse effects. The size of the exposed population and the magnitude and duration of exposures are also unknown. The goal of this section, then, is to point the discussion in directions dictated by the findings of the two previous sections, and to raise questions about the nature of health impacts that may be experienced by those exposed to the exhaust emissions, fugitive dust, and noise from leaf blowers in both occupational and non - occupational settings. Leaf - blower operators and bystanders have two different types of exposures to exhaust and fugitive dust emissions: exposures that occur on a regional basis and exposures that occur when one is within a short distance of the leaf blower. Regional exposures are those exposures to air pollution that occur as a result of leaf blowers contributing to the basin -wide inventory of ozone, carbon monoxide, particulates, and toxic air pollutants. While leaf blowers contribute a small percentage to the basin -wide air pollution, they are nonetheless a source of air pollution that can be, and is, controlled through exhaust emission standards. The second type of exposure is of greater concern. Lawn and landscape contractors, homeowners using a leaf blower, and those in the immediate vicinity of a leaf blower during and shortly after operation, are exposed to potentially high exhaust, fugitive dust, and noise emissions from leaf blowers on a routine basis. While ARB staff have not located conclusive data on how often, how long, and at what concentrations exposures occur, the ARB off -road model assumes that each commercial leaf blower is used for 275 hr /yr, and each residential leaf blower is used for 10 hr /yr. These figures do not tell us, however, how long each leaf blower operator is exposed. Because of the highly speculative nature of the data on operator and bystander exposure time, staff have been unable to develop estimates of the quantities of chemicals individuals could be exposed to per amount of time. Instead, impacts are presented somewhat qualitatively, with recommendations for appropriate personal protection or controls from hazards that staff have found to be significant. A. The Leaf Blower Operator In this section, data are presented that apply to the commercial leaf blower operator, a person who regularly uses the leaf blower in the course of a landscaping or gardening job. Staff assume that a commercial leaf blower operator will use equipment with a higher horsepower than a residential, or homeowner, operator. .. 1. Exhaust Emissions The typical leaf blower owned and operated by commercial lawn and landscape contractors, with an average horsepower of three and a load factor of 50% based on the ARB off - road emissions model, produces the estimated average emissions for a one hour usage as shown in Table 9. Actual operator usage apparently ranges frorh 15 minutes to a Rill work day (Table 7). To illustrate the magnitude of potential exhaust and fugitive dust emissions, staff have compared the estimated leaf blower emissions to the emissions from one hour of operation of two different types of light duty vehicles, one new and one old. A comparison of emissions from leaf blowers to vehicle engines is relevant to provide some sense of the relative quantities of pollutants. Table 9. Commercial Leaf Blower Emissions Compared to Light Duty Vehicle Emissions 3 hp average, 50% load factor, 1999 emissions data *New light duty vehicle represents vehicles one year old, 1999 or 2000 model year, driven for one hour at 30 mph. * *Older light duty vehicle represents vehicles 1975 model year and older, pre- catalytic vehicle, driven for one hour at 30 mph. For CO (Table 9), the estimated 423 g emitted by one hour of leaf blower use is approximately 26 times the amount emitted by a new vehicle, but approximately one -third of the CO emissions of an older vehicle. While not implying that the operator will inhale this amount of CO, these data do suggest concern about the relatively large amount of CO emitted directly into the air space surrounding the operator. For particulate matter exhaust emissions, the leaf blower emits eight to 49 times the particulates of a light duty vehicle, primarily because of the large amount of unburned fuel directly released by the two- stroke engine. Another way to visualize the data is to compare emissions for a given amount of leaf blower operation to miles traveled by cat. The Air Resources Board regularly publishes such emissions benchmarks. Thus, for the average 1999 leaf blower and car data presented in Table 9, we calculate that hydrocarbon emissions from one -half hour of leaf blower operation equal about 7,700 miles of driving, at 30 miles per hour average speed. The carbon monoxide emission benchmark is signficantly different. For carbon monoxide, one -half hour of leaf blower useage 50 Exhaust Emissions, g/hr Exhaust Emissions, new light duty vehicle,* g /hr Exhaust Emissions, older light duty vehicle, ** g /hr Hydrocarbons 199.26 0.39 201.9 Carbon Monoxide 423.53 15.97 1310 Particulate Matter 6.43 0.13 0.78 Fugitive Dust 48.6 -1031 N/A N/A *New light duty vehicle represents vehicles one year old, 1999 or 2000 model year, driven for one hour at 30 mph. * *Older light duty vehicle represents vehicles 1975 model year and older, pre- catalytic vehicle, driven for one hour at 30 mph. For CO (Table 9), the estimated 423 g emitted by one hour of leaf blower use is approximately 26 times the amount emitted by a new vehicle, but approximately one -third of the CO emissions of an older vehicle. While not implying that the operator will inhale this amount of CO, these data do suggest concern about the relatively large amount of CO emitted directly into the air space surrounding the operator. For particulate matter exhaust emissions, the leaf blower emits eight to 49 times the particulates of a light duty vehicle, primarily because of the large amount of unburned fuel directly released by the two- stroke engine. Another way to visualize the data is to compare emissions for a given amount of leaf blower operation to miles traveled by cat. The Air Resources Board regularly publishes such emissions benchmarks. Thus, for the average 1999 leaf blower and car data presented in Table 9, we calculate that hydrocarbon emissions from one -half hour of leaf blower operation equal about 7,700 miles of driving, at 30 miles per hour average speed. The carbon monoxide emission benchmark is signficantly different. For carbon monoxide, one -half hour of leaf blower useage 50 (Table 9) would be equivalent to about 440 miles of automobile travel at 30 miles per hour average speed. Exposure data are necessary to determine potential health impacts of the pollutants. Since few exposure data exist, staff have developed a model that estimates potential exposures based on 10 minutes of leaf blower operation and compares those emissions to the amount of still air in which emissions would need to be mixed to avoid a transitory, local exceedance of the ambient air quality standards, which are health -based standards. Details of the model and results are presented in Appendix J. The exposure scenario suggests that 10 minutes of leaf blower usage could expose the operator to a significant, potentially harmful dose of CO, assuming a worst case exposure, in which there is no dispersion of pollutants out of the immediate area. In this case, the operator could be exposed to potentially harmful amounts of carbon monoxide. The best case would be that all emissions and fugitive dust from the leaf blower would be blown out of the immediate area, resulting in little or no exposure to the operator. Actual exposures would most likely be somewhere in between these two assumptions and would vary greatly with weather conditions, wind, use or nonuse of protective gear, walking speed of the operator, and type of machine used. In addition, for carbon monoxide exposures, whether or not the operator has heart disease would be important in determining potential risk. Exposure studies would need to be conducted to obtain more reliable estimates of operator exposure, and staff recommend further research. On December 27, 1999, ARB was mailed a redacted copy of a 1995 report on operator exposure levels for several chemicals that are present in handheld gasoline - powere equipment exhaust emissions. The report summarized breathing zone measurements during operation of chain saws, a string trimmer, and a leaf blower, but all data pertaining to equipment other than the leaf blower was blacked -out. The study and its limitations are discussed in some detail in Appendix H, but it is relevant to note here that ARB has received two measurements from one leaf blower of breathing zone concentrations of carbon monoxide, toluene, benzene, 1,3- butadiene, acetaldehyde, and formaldehyde. As reported in the study, concentrations of carbon monoxide, benzene, and 1,3- butadiene were high enough as to reinforce concern over operator exosures for the commercial leaf blower operator. 2. Fugitive Dust Estimated fugitive dust emissions cannot be compared to light duty vehicle exhaust. The worst case exposure scenario, however, suggests that ten nninutes of use of a commercial blower would exposure the operator to signiificant amounts of PM (Appendix J). While leaf blower operators would not be expected to spend significant amounts of time within such a particulate cloud, the day -in- day -out exposure to this much PM10 could result in.serious, chronic health consequences in the long -term. Short-term exposures of one to two days to high levels of PM can lead to coughing and minor throat irritation. Long -term exposures have shown statistically significant associations of ambient PM levels with a variety of negative human health outcomes, as discussed previously. These data strongly suggest that professional leaf blowers operators, and 51 those regularly working within the envelope described above, should wear a face mask effective at filtering PM from the air, and further research is warranted. 3. Noise The potential health impacts of leaf blowers on workers from noise center on noise- induced hearing loss. Two factors contribute to an increased risk of hearing loss in typical career gardeners: the high sound pressure levels emitted by leaf blowers at the level of the operator's ear, and the infrequent use of hearing protection. While we cannot estimate the percentage of workers who will experience noise- induced hearing loss without additional data, these two factors are likely to be responsible for hearing loss in an unknown percentage of workers, although individuals may not notice any hearing loss until many years have passed. In order to reduce potential hearing loss, employers should ensure that employees use hearing protection. State and local health and enforcement agencies should promote hearing protection in campaigns targeted at professional landscapers and gardeners. Hearing loss is gradual, and may become obvious only years after the exposure has ceased. B. The Public -at -Large Those who are not working in landscaping and gardening fall into two categories: homeowners doing their own gardening and bystanders. Homeowners who chose to use a leaf blower likely experience relatively low -level exposures which they control. Bystanders may experience low or high exposures, depending on the nature of the exposure. Bystanders, however, almost never have chosen to be exposed to the exhaust, dust, and noise emissions of the leaf blower. Thus their attitude toward the leaf blower is likely very negative and they may be highly annoyed by the exposure. in addition, staff have received letters, and read testimonials on Internet web- sites, concerning acute symptoms, such as asthma and' allergies, exhibited by sensitive individuals to relatively limited exposures. These symptoms have not been evaluated in this report as they are anecdotal and unable to be substantiated. The recent study by Miguel et al. (1999), however, lends support to those who claim that exposure to leaf blower- generated dust causes allergic and asthmatic symptoms. It is also important to acknowledge that some individuals may be very sensitive to the emissions from leaf blowers and .unable to tolerate exposures that do not seem to bother other individuals. In addition to homeowner -leaf blower operators and bystanders who are in the vicinity of leaf blower operation, everyone is exposed to a small degree to air pollution that results from exhaust and dust emissions from leaf blowers. This report does not quantify those exposures, but the ARB does regulate exhaust emissions from leaf blowers, as from most other sources of air pollution. All sources of air pollution need to be reduced in order that Californians can breathe clean air. 52 1. Exhaust Emissions The typical leaf blower owned and operated by a homeowner for private residential use is assumed to have an average horsepower of 0.8 and a load factor of 50 %, based on the ARB off - road emissions model. Emissions from one hour of operation are compared to exhaust emissions from two different age light duty vehicles (Table 10). There are few data available on the length of time a homeowner runs a leaf blower, but it is likely that the homeowner uses a leaf blower for less than one hour, which would reduce the potential exposures and impacts. Table 10. Homeowner Leaf Blower Emissions Compared to Light Duty Vehicle Emissions 0.8 hp average, 50% load factor, 1999 emissions data *New light duty vehicle represents vehicles one year old, 1999 or 2000 model year, driven for one hour at 30 mph. * *Older light duty vehicle represents vehicles 1975 model year and older, pre - catalytic vehicle, driven for one hour at 30 mph. As with the heavier -duty commercial leaf blower, CO and particulate matter emissions from the lighter -duty leaf blower are many times higher than emissions of the same pollutants from vehicles (Table 10). CO emissions from a leaf blower that might be used by a typical homeowner are significantly lower than those from a commercial leaf blower (Table 9) and it is likely that homeowners use leaf blowers for much less than one hour at a time. The exposure scenario for homeowner usage (Appendix J) estimates a correspondingly lower potential exposure. The homeowner is, therefore, less likely to be exposed to potentially harmful amounts of carbon monoxide, although sensitive individuals should be cautioned. For all exhaust emissions, exposures are considerably lower in a residential setting than in a commercial setting. In the best case, all emissions and fugitive dust from the leaf blower would be blown out of the operator's immediate area, resulting in little or no exposure. Actual exposures would most likely be somewhere in between these two assumptions and would vary greatly with weather conditions, wind, use or nonuse of protective gear, walking speed of the operator, and type of machine used. Exposure studies would need to be conducted to obtain more reliable estimates of operator exposure, and staff recommend further research. 53 Exhaust Emissions, g/hr Exhaust Emissions, new light duty vehicle,* g /hr Exhaust Emissions, older light duty vehicle, ** g /hr Hydrocarbons 56.73 0.39 201.9 Carbon Monoxide 119.2 15.97 1310 Particulate Matter 1.44 0.13 0.78 Fugitive Dust 48.6 -1031 N/A N/A *New light duty vehicle represents vehicles one year old, 1999 or 2000 model year, driven for one hour at 30 mph. * *Older light duty vehicle represents vehicles 1975 model year and older, pre - catalytic vehicle, driven for one hour at 30 mph. As with the heavier -duty commercial leaf blower, CO and particulate matter emissions from the lighter -duty leaf blower are many times higher than emissions of the same pollutants from vehicles (Table 10). CO emissions from a leaf blower that might be used by a typical homeowner are significantly lower than those from a commercial leaf blower (Table 9) and it is likely that homeowners use leaf blowers for much less than one hour at a time. The exposure scenario for homeowner usage (Appendix J) estimates a correspondingly lower potential exposure. The homeowner is, therefore, less likely to be exposed to potentially harmful amounts of carbon monoxide, although sensitive individuals should be cautioned. For all exhaust emissions, exposures are considerably lower in a residential setting than in a commercial setting. In the best case, all emissions and fugitive dust from the leaf blower would be blown out of the operator's immediate area, resulting in little or no exposure. Actual exposures would most likely be somewhere in between these two assumptions and would vary greatly with weather conditions, wind, use or nonuse of protective gear, walking speed of the operator, and type of machine used. Exposure studies would need to be conducted to obtain more reliable estimates of operator exposure, and staff recommend further research. 53 As,discussed in Section IV. A. 1., another way to visualize the data is to compare emissions for a given amount of leaf blower operation to nines traveled by car. The Air Resources Board regularly publishes such emissions benchmarks. Thus, for the average 1999 homeowner - type leaf blower and car data presented in Table 10, we calculate that hydrocarbon emissions from one -half hour of leaf blower operation equal about 2,200 miles of driving, at 30 miles per hour average speed. The carbon monoxide emission benclunark is signficantly different. For carbon monoxide, one -half hour of a homeowner -type leaf blower useage (Table 10) would be equivalent to about 110 miles of automobile travel at 30 miles per hour average speed. 2. Fugitive Dust Emissions For fugitive dust, because the homeowner is likely using leaf blowers for a very short time each week, the potential risk from exposure is much lower than for commercial gardeners. Still, based on estimates in the exposure scenario (Appendix J), staff recommends that even homeowners wear a dust filtering mask when using a leaf blower. 3. Noise The homeowner who uses a leaf blower for a brief amount of time each week or two is unlikely to experience noise - induced hearing loss. The cumulative exposure to many recreational sources of noise, such as recreational power tool use, lawn care, shooting, boating, concert - going, and other activities that expose one to loud noises, however, is likely to be great enough to impact hearing (Clark 1991). Those who regularly use noisy power equipment should be in the habit of using hearing protection to reduce their overall exposure to potentially damaging noise. The likelihood of a bystander exposed to leaf blower noise on an irregular basis experiencing hearing loss is low. The potential health impacts from leaf blowers on bystanders that are likely more important include interference with communication, sleep interruption, and annoyance. Each of these impacts may in turn lead to stress responses, although research has not conclusively tied chronic exposures with any particular adverse health outcome. Although interference with communication, sleep interruption, and annoyance may not seem to be serious impacts, they are important health and quality of life issues for many people. At least 100 municipalities in California have restricted or banned the use of leaf blowers within city limits in response to people who object to the loud noise of leaf blowers interrupting their lives. 54 C. Summary of Potential Health Impacts Health effects from hazards identified as being generated by leaf blowers ranging from mild to serious, but the appearance of those effects depends on exposures: the dose; or how much of the hazard is received by a person, and the exposure time. Without reasonable estimates of exposures, ARB cannot conclusively determine the health impacts from leaf blowers; the discussion herein clearly is about potential health impacts. The goal is to direct the discussion and raise questions about the nature of potential health impacts for those exposed to the exhaust emissions, fugitive dust, and noise from leaf blowers in both occupational and non - occupational settings. For the worker, the analysis suggests concern. Bearing in mind that the worker population is most likely young and healthy, and that these workers may not work in this business for all of their working lives, we nonetheless are cautioned by our research. Leaf blower operators may be exposed to potentially hazardous. concentrations of CO and PM intermittently throughout their work day, and noise exposures maybe high enough that operators are at increased risk of developing hearing loss. While exposures to CO, PM, and noise may not have immediate, acute effects, the potential health impacts are potentially greater for chronic effects. In addition, evidence of significantly elevated concentrations of benzene and 1,3- butadiene in the breathing zone of workers leads to concern about exposures to these two toxic air contaminants. Potential noise and PM effects should be reduced by the use of appropriate breathing and hearing protective equipment. Employers should be more vigilant in requiring and ensuring their employees wear breathing and hearing protection. Regulatory agencies should conduct educational and enforcement campaigns, in addition to exploring the extent of the use of protective gear. Exposures to CO and other air toxics are more problematic because there is no effective air filter for these air pollutants. More study of CO and other air toxics exposures to leaf blower operators is warranted to determine whether the potential health effects discussed herein are actual effects or not. Describing the impacts on the public -at -large is more difficult than for workers because people's exposures, and reactions to those exposures, are much more variable. Bystanders are clearly annoyed and stressed by the noise and dust from leaf blowers. They can be interrupted, awakened, and may feel harassed, to the point of taking the time to contact public officials, complain, write letters and set up web sites, form associations, and attend city council meetings. These are actions taken by highly annoyed individuals who believe their health is being negatively impacted. In addition, some sensitive individuals may experience extreme physical reactions, mostly respiratory symptoms, from exposure to the kicked up dust. On the other hand, others voluntarily purchase and use leaf blowers in their own homes, seemingly unnnune to the effects that cause other people such problems. While these owner- operators are likely not concerned about the noise and dust, they are should still wear protective equipment, for example, eye protection, dust masks, and ear plugs, and their exposures to CO are a potential problem and warrant more study. W V. RECOMMENDATIONS The Legislature asked ARB to include recommendations for alternatives in the report, if ARB determines alternatives are necessary. This report makes no recommendations for alternatives. Based on the lack of available data, such conclusions are premature at this time. Exhaust standards already in place have significantly reduced exhaust emissions from the engines used on leaf blowers, and manufacturers have reduced CO emissions further than required by the standards. Ultra -low or zero exhaust emitting leaf blowers could further reduce public and worker exposures. At its January 27, 2000, public hearing, the Air Resources Board directed its staff to explore the potential for technological advancement in this area. For noise, the ARB has no Legislative mandate to control noise emissions, but the evidence seems clear that quieter leaf blowers would reduce worker exposures and protect hearing, and reduce negative impacts on bystanders. In connection with this report, the Air Resources Board received several letters urging that ARB or another state agency set health - based standards for noise and control noise pollution. A more complete understanding of the noise and the amount and nature of dust . resuspended by leaf blower use and alternative cleaning equipment is suggested to guide decision - making. Costs and benefits of cleaning methods have not been adequately quantified. Staff estimates that a study of fugitive dust generation and exposures to exhaust emissions and dust could cost $1.1 million, require two additional staff, and take two to three years. Adding a study of noise exposures and a comparison of leaf blowers to other cleaning equipment could increase study costs to $1.5 million or more (Appendix H). Fugitive dust emissions are problematic. The leaf blower is designed to move relatively large materials, which requires enough force to also blow up dust particles. Banning or restricting the use of leaf blowers would reduce fugitive dust emissions, but there are no data on fugitive dust emissions from alternatives, such as vacuums, brooms, and rakes. In addition, without a more complete analysis of potential health impacts, costs and benefits of leaf blower use, and potential health impacts of alternatives, such a recommendation is not warranted. Some have suggested that part of the problem lies in how leaf blower operators use the tool, that leaf blower operators need to show more courtesy to passersby, shutting off the blower when people are walking by. Often, operators blow dust and debris into the streets, leaving the dust to be resuspended by passing vehicles. Interested stakeholders, including those opposed to leaf blower use, could join together to propose methods for leaf blower use that reduce noise and dust generation, and develop and promote codes of conduct by workers who operate leaf blowers. Those who use leaf blowers professionally would then need to be trained in methods of use that reduce pollution and potential health impacts both for others and for themselves. 56 VI. REFERENCES CITED Air Resources Board, Staff report: Initial Statement of Reasons (ISOR) for the public hearing to consider amendments to the 1999 small off -road engine regulations. Mailout MSC #98 -02, January 1998a; ,[online at: http: // arbis. arb .ca.gov /regact/sore /sore.htm]. Air Resource Board. Notice of public meeting to consider the approval of California's 1990 small off -road engine emission inventory. Mailout MSC #98 -04, March 1998b. Air Resources Board. Compound summaries, Toxic Air Contaminant identification list. Acetaldehyde, pp 1 -5; Benzene, pp 91 -96; 1,3- Butadiene, pp 141 -145; Formaldehyde, pp 513 -517. [Online at http: / /arbis. arb ,ca.gov /toxicx /tac /toetbl.htm] September 1997. Air Resources Board, Research Division. Cardiac response to carbon monoxide in the natural environment. Contract no. A3- 138 -33. 1992. Allen, Jack; Legislative Liaison for Zero Air Pollution, letter to Nancy Steele, Air Resources Board, July 29, 1999a. Allen, Jack; Coalition to Ban Leafblowers, letter to Dr. Nancy Steele, Air Resources Board, October 5, 1999b. AAP (American Academy of Pediatrics), Committee on Environmental Health. Noise: A Hazard for the Fetus and Newborn (RE9728). Pediatrics, 100(4), 1997; [online at: http: / /www.aap.org /policy /re9728.html, 07/08/99]. Anonymous (confidential), Research & Development Laboratory, Leafblower Usage Survey, Commercial Contractors /So. California, February 1999. Barnthouse, L.; Fava, J.; Humphreys, K.; Hunt, R.; Laibson, L.; Noesen, S.; Norris, G.; Owens, J.; Todd, J.; Vigon, B.; Weitz, K.; & Young, J.; Life -cycle Impact Assessment: the State - of -the -art, 2nd ed. Report of the SETAC Life -Cycle Assessment Impact Assessment Workgroup. 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Letter to Dr. Nancy Steele, ARB, October 8, 1999, 12 pp plus attaclunents. IME (International Marketing Exchange, hie.). City list of noise activity as of July 16, 1999. Inventory of documents, July 1999. 59 Kryter, KD. The Handbook of Hearing and the Effects of Noise: Physiology, Psychology, and Public Health. Academic Press: San Diego, 1994. League for the Hard of Hearing. Noise Levels in our Environment Fact Sheet, March 19, 1999; [online at: http: / /www.lhh.org /noise /decibel.htm, 06/15/99]. LINK (Landscapers Involved With Neighborhoods and Kids). Website, 1999; [online at: www.concentric.net/ — Wrigfam, 7/23/1999]. Maisarah, SZ; Said, H. The noise exposed factory workers: the prevalence of sensori - neural hearing loss and their use of personal hearing protection devices. Med. J Malaysia, 48: 280 -285, 1993. Mathews, KE, Jr.; Canon, LK. Environmental noise level as a determinant of helping behavior. J of Personality and Social Psychology, 32: 571 -577, 1975. McGuire, T. Air Pollution from Leaf Blowers, letter to RG Johnson, Sacramento Metropolitan Air Quality District. Air Resources Board, Technical Support Division; July 9, 1991. Miguel, AG; Cass, GR; Glovsky, MM; Weiss, J. Allergens in paved road dust and airborne particles. Environ. Sci. & Technol , 33: 4159 -4168, 1999. MRI (Midwest Research Institute). Fugitive Particulate Matter Emissions, Final Report for U.S EPA; MRI Project No. 4604 -06. Kansas City, Missouri, April 15, 1997. MPCA (Minnesota Pollution Control Agency). An Introduction to Sound Basics. St. Paul, MN, 1987; [online at: littp: / /www.nonoise.org/ library /sndbasic /sndbasic.htm, 07/08/991. Muleski, Gregory E., Midwest Research Institute. Personal communication with Hector Maldonado, Air Resources Board, August 1999. Nakamura, Douglas, Northwest Landscape Maintenance, in a letter to Dr. Nancy Steele, ARB; October 8, 1999, 2 pp. NIOSH (National Institute for Occupational Safety and Health). Criteria for a recommended standard occupational noise exposure, revised criteria. Draft document; August 12, 1996; [online at: http: / /www.nonoise.org /library /`nosh/criteria.htm,. 8/12/99]. NRC (National Research Council). Risk Assessment in the Federal Government: Managing the Process. National Academy Press: Washington, D.C., 1983. Omenn, GS; Kessler, AC; Anderson, NT; Chin, PY; Doull, J; Goldstein, B; Lederberg, J; McGuire, SM; Rall, D; Weldon, W; Charnley, G. Risk Assessment and Risk Management no in Regulatory Decision Making, Vol. 2. Presidential/Congressional Commission on Risk Assessment and Risk Management, Washington, D.C., 1997. Orange County Grand Jury. Leaf Blower Pollution Hazards in Orange County. Orange County Council of Governments, February 17, 1999. PPEMA (Portable Power Equipment Manufacturers Association). Hand held gasoline powered equipment 1998 U.S. shipments and 1999 outlook. Press release. March 8, 1999. Rippey, Mary, Labor Market Information Division, California Employment Development Department. Personal communication with Nancy Steele, August 4, 1999. SCAQMD.(South Coast Air Quality Management District). Final staff report, proposed rule 1623 - credits for clean lawn and garden equipment. Diamond Bar, CA, May 1996. Schulze, LJH; Lucchesi, J. Sound pressure levels of common lawn equipment used in the industrial and non - industrial work environment. Presented at American Industrial Hygiene Conference and Exposition, Dallas, TX, 1997. Seinfeld, JH, and Pandis, SN. Atmospheric Chemistry and Physics - From Air Pollution to Climate Change. Wiley & Sons: New York, 1998. Shapiro, SA. The Dormant Noise Control Act and Options to Abate Noise Pollution. Administrative Conference of the United States, November 1991; [online at: http: / /www.nonoise.org /library /shapiro /shapiro.litm, 06/15/99]. Smaus, R. Leaf blowers make for barren earth. Los Angeles Times, K10, K15., July 13, 1997. Stevens, SS. The measurement of loudness. J. Acoust. Soc. 4m., 27: 815 -829, 1955. Suter, AH. Noise and its effects. Administrative Conference of the United States, November 1991; [online at: http: / /www.nonoise.org /library /suter /suter.htm, 06/15/99]. Talbott, EO; Rindlay, RC; Kuller, LH; Lenkner, LA; Matthews, KA; Day, RD; Ishii, EK. Noise - induced hearing loss: a possible marker for high blood pressure in older noise - exposed populations. J. Occup. Med., 32: 690 -697, 1990. U.S. EPA, Office of Air and Radiation. Phase 2 emission standard for new nonroad spark - ignitiion handheld engines at or below 19 kilowatts; proposed rule. 64 Federal Register 40940 - 40972; July 28, 1999a. U.S. EPA, Office of Research and Development. Air quality criteria for carbon monoxide. External review draft. EPA/600/P- 99/001. Washington, D.C., 1999b. 61 U.S. EPA, Office of Air and Radiation. Compilation of Air Pollutant Emission Factors, Volume II, Mobile Sources, Section IL, Nonroad Mobile Sources; 4P -42, 4th Edition, Washington, D.C., 1997. U.S. EPA, Office of Research and Development. Air quality criteria for particulate matter. EPA /600/P- 95 /00laF. Washington, D.C., 1996, U.S. EPA, Office of Noise Abatement and Control. Noise in America; the extent of the noise problem. EPA 550/9 -81 -101. Washington, D.C., September 1981. U.S. EPA, Office of Noise Abatement and Control. Information of levels of environmental noise requisite to protect public health and welfare with can adequate margin of safety. EPA/ONAC 55019 -74 -004, Washington, DC, March 1974; [online at; www.nonoise.org /library /levels74 /levels74.htm, 7/15/1999]. Venkatram, A; Fitz, DR. Measurement and modeling of-PM10 and PM2.5 emissions from paved roads in California. Phase I Final Report, ARB #94 -336. Prepared for the Air Resources Board. November 1998. Will, Larry, Vice President, Engineering, Echo Incorporated. Personal communication with Nancy Steele, August 1999a. Will, Larry, Vice President, Engineering, Echo Incorporated, in a letter to Dr. Nancy Steele, ARB, September 23, 1999b. Wolfberg, D; Wolfberg, G. Survey 99 Report. ZAP Education Committee, Los Angeles, CA. September 28, 1999. Yardemiam, Vasken, Transportation Specialist, SCAQMD, Diamond Bar, CA. Personal communications with Nancy Steele, ARB, July 1999. Zero Air Pollution. A study of operator observance of safety instructions for gas powered leaf blowers and of time of use of blowers. Prepared by Jack Allen, Chairman, Research Committee, Pacific Palisades, CA. August 30, 1999. Zinko, C. Leaf - blower showdown on way in Palo Alto. San Francisco Chronicle, A22, February 2, 2000. Zwerling, E. Electronic communications with Nancy Steele, October 1999, 8 pp. 62 115:111 RESEARCH NEEDS Exhaust Emissions The ARB has an active research program to determine exhaust emissions from engines that it regulates. Existing and future exhaust emission control standards will continue to require that manufacturers reduce emissions from the small off -road engines found in leaf blowers. Staff conducts periodic reviews of technology to determine whether further emission reductions are possible. For example, the ARB has recently awarded a contract to the Southwest Research Institute to conduct research entitled "Particulate Emissions from Marine Outboard Engines, Personal Watercraft and Small Off -Road Equipment." The objectives relevant to leaf blower technology are (1) to measure the emissions from two - stroke engines used in small off -road equipment, with an emphasis on PM emissions and polycyclic aromatic hydrocarbon levels; and (2) to determine particle size distribution and mutagenic toxicity of the PM. The contractor will obtain and test five engines typically used in leaf blowers or similar off -road equipment, and staff have recommended that engines used in leaf blowers be among those chosen. In addition to this study, staff has identified investigation into small off -road engine deterioration as an area for future research; engine deterioration causes emissions to increase with engine usage. In general, research into annual usage data, both for the leaf blower equipment and for the operator, would be helpful. The estimated annual usage in the inventory may be lower than actual usage, and may not correlate well with how long an operator, commercial or residential, uses the equipment throughout the year. Fugitive Dust ARB staff found a fundamental lack of information on the nature and quantity of fugitive dust blown, or resuspended, by leaf blowers. Empirical data are needed, however, as calculations only go so far. Any study would need to consider a large number of variables, such as substrate, humidity, seasonality, and type of materials being moved by the leaf blower. Ideally, as part of a future research project, one would want to first quantify the emissions in actual use by: (1) inventorying the types of surfaces cleaned by leaf blowers statewide, and by air district, (2) determining the silt loading for surfaces that are cleaned, and (3) performing source testing to determine the amount of PM30, PM 10 and PM2.5 entrained in the air, and to determine the "exposure envelope" associated with leaf blower usage. This information could then be used to calculate more accurate estimates of dust associated with leaf blower usage. In addition to quantifying emissions, it would also be important to determine what is in the dust. This information would not be applicable only to leaf blowers, but would reflect what is in dust that is resuspended by wind from any source. Presently, chemical speciation data are available for sources such as paved and unpaved roadways. For leaf blowers, we should also examine the make -up of dust from lawns, sidewalks, parking lots, and flower beds. In addition to chemical speciation, it would also be useful to analyze the dust for the presence of herbicides, pesticides, bacterial endotoxins, and other toxins. Noise Emissions The investigation and reduction of noise emissions is not part of the ARB's authority or mission. Traditionally, noise control and abatement has been a local function, although a state Office of Noise Control did exist for a short time; the Office was housed within the Department of Health Services. Quantifying noise exposures of landscape and gardening workers might be conducted as a part of a larger ARB effort aimed at better understanding the leaf blower population and annual hours of use. Otherwise, most noise related research would be better conducted by other state agencies. Quantify the number of Californians affected by noise and noise exposure levels. The purposes of this study would be two - fold: First, to assess the number of workers who are exposed to leaf blower noise, the number of hours they are exposed daily, and their daily noise dose and exposures. Second, to determine the number of people exposed non- occupationally to leaf blower noise, average noise exposures, frequency of exposure (e.g., daily, weekly), and how they are affected (e.g., annoyed, interference with sleep or communication). Agencies potentially responsible for this study would include ARB; the Office of Environmental Health Hazard Assessment; and the California Department of Health Services Occupational Health Branch. Evaluate hearing loss in gardeners, emphasizing those who use leaf blowers as a part of their work. The purpose of this study would be to evaluate, more specifically, the incidence of noise - induced hearing loss in occupationally exposed gardeners. Non - occupational exposure to noise would also need to be assessed. Agencies potentially responsible would include the California Department of Health Services Occupational Health Branch. Exposure Data and Potential Health Impacts Exposure data are needed to determine potential health effects, particularly from CO, particulates, and noise. On December 27, 1999, ARB was mailed a redacted copy of a 1995 report entitled "Evaluation of Chemical Emissions From White Consolidated Industries Products "1 (WCI). The WCI report was prepared for Poulan /Weed Eater to determine operator exposure levels for several chemicals that are present in handheld gasoline - powered 1 Batelle. Evaluation of chemical emissions from Wlute Consolidated Industries products, final report. Prepared for Poulan/Weed Eater, Division of WCI Outdoor Products, Inc. Batelle: Columbus Operations. October 1995. equipment exhaust emissions, specifically chemicals that are listed under California's "Proposition 65" law as either carcinogens or reproductive or developmental toxins. Batelle, which prepared the WCI report, measured breathing zone concentrations during operation of a leaf blower, three chain saws, and a string trimmer and calculated user exposures. Before sending the report to ARB, however, all data relating to the chain saws and string trimmer were blacked -out. The WCI report presents the only data on operator exposures from leaf blowers known to ARB at this time. As noted, exposure data are crucial for determining health impacts. Although the WCI report was received too late for discussion in the body of the leaf blower report, the following summary and analysis of the results of the WCI report are included in this appendix. The WCI study measured breathing zone exposures of operators of certain power equipment to six toxic chemicals: formaldehyde, acetaldehyde, benzene, 1,3- butadiene, toluene, and carbon monoxide. The leaf blower tested was a consumer model with an engine displacement of 32 cc and engine horsepower of 0.9; the blower was run at full throttle for 30 minutes in each of two tests. Concentrations of the six toxic chemicals were measured and user exposures were calculated based on specified assumptions. The WCI report concludes that "[m]easured concentrations and calculated user exposures are below all existing concentration standards and Prop 65 allowable exposures.... Consequently, operator exposures to the target chemicals from normal use of WCI power equipment do not convey significant health risks as established under Prop 65." Study limitations include a small sample size and potential bias towards conditions that could minimize risk calculations. As only one leaf blower was tested, the results cannot be assumed to represent all leaf blowers. As only two samples were collected from the leaf blower, the results are likely not representative of breathing zone concentrations that would be experienced by a variety of operators. Conditions during the test that could minimize measured concentrations, and thus underestimate risk, include 10 mph winds, one start -up per test (emissions are higher during start -up), and the use of a new, properly tuned leaf blower. Typically, older equipment emits more pollutants. In addition, the user exposure is calculated by assuming that 30- minutes is the maximum time of exposure for all users, and Batelle represents this as a "worst case" exposure. It is more likely that this represents a "best case" scenario for exposure, however, and that 8 -hours of exposure would more likely represent a "worst case" scenario. Given these limitations, the WCI report supports ARB's conclusion that additional research is needed to better understand operator exposures to hazards and provides further evidence for concern regarding operator exposures to exhaust emissions. Table 1. WCI Report Calculated Daily Exposure Levels Weed Eater Measured Ambient Air WCI WCI Standards model GBI -30V, Conc. Conc. Adjusted Calculated (pg /day) 0.9 hp engine (pg /m3) (pg /m3) Conc. User Exposure p /m3 /da Formaldehyde 33.1, 28.1 22.6, 23.4 7.6 0.31 40* Acetaldehyde 23.0, 22.2 12.3, 17.5 7.7 0.31 90* Toluene 265, 144 2.0, 1.7 55.3 84 13,000+ Benzene 67.2, 45.2 0.84, 1.02 203 2.25 7* 1,3- Butadiene 0.92, <0.15 <0.15, 0.39 0.02 0.4* <0.15 Carbon 3435,6870 1145, 4010 20051 40000# Monoxide, ave. <1145 Carbon 29800, 3435, 1145 34400 34400T 458000 ** Monoxide, peak 43500 j-Assumes 30 minute exposure averaged over one -hour, in pg /m3; an 8 -hour exposure is assumed to be 250 pg /m3, or 2005 pg /m3 divided by 8 hours. $Measured peak in units of pg /m3 *Prop 65 No Significant Risk Level +Prop 65 Acceptable Daily Intake Level #U.S. EPA One Hour Ambient Air Quality Standard (The California one hour standard is 23,000 pg /m3) * *ACGIH Workplace Short Term Exposure Limit (15 min) A draft research plan to begin assessment of potential health impacts of leaf blowers on operators and the public -at -large is included herein as a starting point to assess tasks and costs: Assessing Potential Health Impacts of Leaf Blowers on Operators and the Public -at -Large This draft, proposed research plan would address two issues related to leaf blower usage in California: First, what is the nature and quantity of fugitive dust resuspended by leaf blower usage; and second, what are the exposures to carbon monoxide, other exhaust emissions, and fugitive dust experienced by leaf blower operators? The proposed research does not include research into noise exposure, although the study could be expanded with outside expert assistance, as ARB does not have a mandate to study noise. The study also would not directly assess exposures experienced by bystanders in the vicinity of someone else using a leaf blower, although the data gathered could be used to make some preliminary estimates regarding these exposures. The estimated cost of the study is $1,100,000. Task 1 - Population and activity survey. $50,000. Determine the population of leaf blowers, by type (backpack engine- powered, wheeled engine- powered, handheld engine - powered, handheld electric), by air district. Determine usage patterns, how many are used by homeowners and how often, and how many by professional gardeners and how often. Also determine the amount of time each leaf blower is used versus the amount of time each person (including non - operators on a gardening crew) are exposed to leaf blower use. This task would involve the development of a survey instrument and may involve the use of data loggers. Task 2 - Methodology development for measuring and calculating fugitive dust (particulate matter) emissions and exposure assessment. $50,000. This task would build on previous data on measuring and calculating emissions, but would involve some new methodology as no previous studies have measured fugitive dust resuspended by leaf blowers. As leaf blowers are often used at the same time as other lawn and garden equipment, this task will include differentiating between emissions from leaf blowers and other equipment. Task 3 - Field study to collect data on exhaust and fugitive dust generation and exposures by operators. $800,000. The study has several facets: Task 3a - Dosimetry of operators to measure CO and other exhaust emissions exposures. Could also include audiodosimeters if noise dose is being measured. Operators participating in the study would keep journal records of activities while working with lawn and garden equipment. Task 3b - Measure silt loadings for representative sites based on where leaf blowers are used, during different climate conditions and /or seasons, and in different regions of the state. Task 3c - Perform fugitive dust emissions sampling and sample collection at selected sites, during selected seasons; data are to be used to estimate both personal exposures, emissions factors, and aggregate daily emission rates. Task 4 - Sample chemical analysis. $100,000. Actual cost depends on number of samples and chemical species analyzed. Cost assumes 50 samples at $2,000 /sample. Study would analyze samples for elements and ions and organic species, such as vegetative detritus, fecal matter, pollen, mold spores, and endotoxins. Task 5 - Data analysis. $30,000. Analyze data and prepare emissions estimates. Include size - segregated PM emissions for emissions inventory and for personal exposure assessment. Task 6 - Quality assurance. $30,000. Determine accuracy of subjects in recording leaf blower usage in daily journals, proper use of dosimetry equipment, and chemical and data analyses. Task 7 - Reporting and final report. $30,000. PARTICULATE MATTER EMISSIONS FACTORS AND EMISSIONS INVENTORY FROM LEAF BLOWERS IN USE IN THE SAN JOAQUIN VALLEY FINAL REPORT Prepared for: San Joaquin Valley Unified Air Pollution Control District 1990 Gettysburg Avenue Fresno, CA 93726 Principal Investigator: Mr. Dennis R. Fitz College of Engineering Center for Environmental Research and Technology University of California, Riverside Riverside, CA 92507 Participating Researchers: David Pankratz, Mark Chitjian, James Bristow and Sally Pederson College of Engineering Center for Environmental Research and Technology University of California Riverside, CA 92521 January 27, 2006 ATTACHMENT 2 Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT DISCLAMER Revision: 2 January 27, 2006 The statement and conclusions in the Report are those of the contractor and not necessarily those of the San Joaquin Valley Unified Air Pollution Control District. The mention of commercial products, their source, or their use in connection with material reported herein is not to be construed as actual or implied endorsement of such products. Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT ACKNOWLEDGEMENTS Revision: 2 January 27, 2006 This research study was made possible by a group of individuals and organizations whose valuable contributions are greatly appreciated. We wish to thank the following organizations and individuals for their time and resources in contributing to the success of the measurement program: 1. The UC Kearney Research and Extension Center for allowing the use of their site in the San Joaquin Valley for some of measurements and particular thanks to Kearney staff members Laura Van der Staay, Bob Ray and Andy Padilla for being helpful and accommodating to the needs of the study. 2. Bob Giese and the staff of the UCR Physical Plant Building Services and Grounds Maintenance for allowing us to follow around the grounds maintenance crew and coordinating with -us- for the collection of samples from areas about to be leaf blown. 3. Joe Patricko, Paul Giering and Russell Vernon with the UCR Environmental Health and Safety Department for reviewing our planned activities, identifying the appropriate personal protective gear (PPG) and loaning us those PPGs. 4. Bourns, Inc. for allowing us to setup our sampling chamber in their parking lot. 5. Professor Mark Matsumoto in the UCR Chemical and Environmental Engineering Department for allowing us to use his sieve shaker. 6. Professor Arthur Winer with the UCLA School of Public Health for loaning his photoionization detector to the project. 7. Professor Marko Princevac in the UCR Mechanical Engineering Department for the loan of two DustTraks for use in the project. iii Final Report PM Emission Faetors and Inventories from Leaf Blowers University of California, Riverside CE -CERT TABLE OF CONTENTS Revision: 2 January 27, 2006 DISCLAIMER................................................................................................. ............................... ACKNOWLEDGEMENTS................................................. ............................... ............................ iii 1.0 EXECUTIVE SUMMARY ....................................................................... ............................... 1 2.0 INTRODUCTION ..................................................................................... ............................... 3 2.1 Background ..................................................................................... ..............................4 2.2 Project Objectives .......................................................................... ............................... 4 2.3 Scope of Work ............................................................................... ............................... 4 3.0 EXPERIMENTAL METHODS AND STUDY DESIGN ......................... ............................... 5 3.1 Instrumentation ............................................................................... ............................... 5 3. 1.1 Real -Time PM Monitors — DustTraks ............................ ............................... 6 3.1.2 Time- Integrated PM Measurements using Filter Samplers ........................... 6 3.1.3 Wind Speed and Wind Direction .................................... ............................... 7 3.1.4 Propene Tracer Gas Measurements ................................ ............................... 8 3.1.5 Data Acquisition System .............................................. ............................... 10 3.1.6 Leaf Blowers ................................................................. ............................... 10 3.1.7 Rakes and Brooms ...................................... . ................. I ........................... ... 13 3.1.8 Surrogate Material Spreading ....................................... ............................... 14 3.1.9 Triple Beam Balance ...................................................... ............................... 14 3.1.10 Sieve Shaker ............................................................... ............................... 14 3.2 Design and Evaluation of Test Chambers .................................... .............................1. 14 3.2.1 Twenty Meter Long Test Chamber ............................... ............................... 15 3.2.2 Initial Evaluation of the 20m Chamber ......................... ............................... 16 3.2.3 Dust Plume Characterization ........................................ ............................... 19 3.2.4 Ten Meter Long Test Chamber ..................................... ............................... 24 3.2.5 Sweeping Patterns in Test Chamber ............................. ............................... 25 3.3 Surrogate and Actual Debris Selection, Preparation and Evaluation ......................... 27 3.3.1 Soil Silt Content ............................................................ ............................... 30 3.4 Data Processing and Validation ................................................... ...............:............... 31 3.4.1 Data Handling ................................................................ ............................... 31 34.2 Data Validation ............................................................. ............................... 32 3.4.3 Data Analysis ................................................................ ............................... 32 3.4.4 Data Precision, Accuracy and Completeness ...........:... ............................... 33 4.0 MEASUREMENTS AND RESULTS ..................................................... ............................... 34 4.1 Study Dates and Conditions ......................................................... ............................... 34 4.2 Test Chamber Characteristics ...................................................... ............................... 35 4.2.1 Twenty Meter Test Chamber Horizontal Characteristics ............................ 35 4.2.2 Twenty Meter Test Chamber Vertical Characteristics . ............................... 37 4,2.3 Ten Meter Test Chamber Horizontal and Vertical Characteristics ............. 39 4.3 DustTrak Calibration Factors ........................:.............................. ............................... 41 4.4 Determination of the Composition of Debris for Leaf Blower Testing ...................... 43 4.5 Emission Factor Measurements ................................................... ............................... 45 4.5.1 Measurement Locations ................................................ ............................... 50 IV Final Report PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 4.6 Data Accuracy, Precision and Completeness .............................. ............................... 55 5.0 EMISSION FACTORS ............................................................................ ............................... 56 6.0 EMISSION INVENTORY ...................................................................... ............................... 58 7.0 REFERENCES ........................................................................................ ............................... 62 APPENDIX A: Quality Integrated Work Plan APPENDIX B: Audit of Filter Sampling Measurement System TABLES Table1. Summary of emission factors ........................................................... ............................... 2 Table 2. Annual emissions in the San Joaquin Valley from leaf blowing activities ....................: 3 Table 3. Particle size analysis of various soil types used .............................. ............................... 30 Table 4. Sieve analysis of the five soils used ................................................ ............................... 31 Table 5. Summary of study activities and meteorological conditions ........... ............................... 34 Table 6. Concentration data (mg /m3) from tests to determine horizontal gradient in 20m .......... " "............. chamber ......................................................................................... ..................... 37 Table 7. Concentration data (mg /m3) from tests to determine vertical gradient in 20m chamber.39 Table 8. Vertical and horizontal concentration gradient data (mg /m3) averaged between 6.0 and 6.5 minutes for I Om chamber . .............................................................................. ......................... 41 Table 9. Collocated DustTrak mean response ratios ..................................... ............................... 42 Table 10. Mass per sieve size for samples collected from area to be leaf blown ......................... 43 Table 11. Percent mass per sieve size for samples collected from area to be leaf blown ............. 44 Table 12 (part 1 of 4). Summary of test run conditions and equipment ........ ............................... 46 Table 12 (part 2 of 4). Summary of test run conditions and equipment ........ ............................... 47 Table 12 (part 3 of 4). Sununary of test run conditions and equipment ........ ............................... 48 Table 12 (part 4' of 4). Summary of test run conditions and equipment ........ ............................... 49 Table 13 (part 1 of 2). Emission test airborne particulate matter concentrations ......................... 51 Table 13 (part 2 of 2). Emission test airborne particulate matter concentrations ........................... 52 Table 14. Leaf blowing emission factors for various soils tested .................. ............................... 53 Table 15. Emission factors for blowing, vacuuming,, raking and sweeping on asphalt surfaces. 54 Table 16. Emission factors for blowing, vacuuming, raking and sweeping on concrete surfaces. ........................................................................................................................ ............................... 54 Table 17. Emission factors for leaf blowing natural /indigenous surfaces ..... ............................... 55 Table 18. Collocated DustTrak data .............................................................. ............................... 55 Table 19. Summary of emission factors ........................................................ ............................... 57 Table 20. Area cleaned per week, non - winter months .................................. ............................... 58 Table 21. Area cleaned per week, winter months .......................................... ............................... 59 Table 22. Emission factors by task ................................................................ ............................... 60 Table 23. Emissions by housing type, non - winter months ............................ ............................... 60 Table 24. Emissions by housing type, winter months ................................... ............................... 60 Table 25. Number of units by housing type ................................................... ............................... 61 v Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Revision: 2 January 27, 2006 Table 26. Leaf blower emissions by county, non - winter months ................. ............................... 61 Table 27. Leaf blower emissions by county, winter months ...................... Table 28. Annual emissions in the San Joaquin Valley from leaf blowing activities .................. 62 FIGURES Figure 1. Project wind system at CE- CERT .................................................... ............................... 7 Figure 2. SJVUAPCD wind system at UC Kearney facility ........................... ............................... 8 Figure 3. Propene tracer gas preparation . ........................................................... :........................... 9 Figure 4. Photoionization analyzer in chamber used to measure propene tracer gas concentration. ........................................................................................................................ ............................... 10 Figure 5. Electric powered hand held blower / vacuum .................................. ............................... 11 Figure 6. Gas powered Band held blower/ vacuum ............................................ ............................... 12 Figure 7. Gas powered backpack blower ....................................................... ............................... 12 Figure 8. Push broom used for study . ..................................... :..................................................... 13 Figure9. Rake used for study ........................................................................ ............................... 13 Figure 10.20m test chamber .......................................................................... ............................... 15 Figure 11. Photographs of 20m test chamber ................................................ ............................... 16 Figure 12. Top view of test chamber showing test material .......................... ............................... 16 Figure 13. Addition of pipe and sandbags along base of chamber to eliminate leaks .................. 17 Figure 14. Respiratory protection equipment used for chamber tests ........... ............................... 18 Figure15. l Om test charnber .......................................................................... ............................... 19 Figure 16. Photographs showing surrogate material laid out in the l Om test chamber ................ 20 Figure 17. DustTrak locations in 20in test chamber for determining horizontal particulate matter distribution..................................................................................................... ............................... 21 Figure 18. Collocated DustTraks at l Om and 16m for horizontal gradient tests .......................... 22 Figure 19. Blowing operation for horizontal gradient tests ........................... ............................... 22 Figure 20. DustTrak locations in 20m test chamber for determining vertical particulate matter distribution..................................................................................................... ............................... 23 Figure 21. DustTrak locations in l Om test chamber for determining horizontal and vertical particulate matter concentration gradients ..................................................... ............................... 24 Figure 22. Drawing of l Om chamber ............................................................. ............................... 25 Figure 23, Photographs of l Om chamber ....................................................... ............................... 25 Figure 24. Surrogate material deployment pattern in l Om chamber ............. ............................... 26 Figure 25. Cleaning patterns for natural /indigenous material with 1 Om chamber ....................... 27 Figure 26. Square meter areas, vacuumed and analyzed just prior to leaf blowing....... ............... 29 Figure 27. Time series of DustTrak TSP responses for horizontal distribution characterization. 36 Figure 28. Time series of DustTrak, responses for vertical distribution characterization ............. 38 Figure 29. Time series of DustTrak responses for horizontal and vertical distribution characterization in I Om chamber .................................................................... ............................... 40 Figure 30. Correlation (all three tests) and time- series plots for eight DustTraks collocated in IOm charnber .................................................................................................. ............................... 42 Figure 31. Collocated DustTrak and filter sampler comparisons .................. ............................... 42 ►ZI Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Figure 32. Photographs showing 20m chamber for surrogate tests........ Figure 33. Photographs showing inside of 20m chamber during testing Figure 34. Photographs showing lawns with lush and lean foliage........ Vii Revision: 2 January 27, 2006 .................. 50 .................. 50 .................. 56 Draft Final Report Page 1 of 63 PM Emission factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 1.0 EXECUTIVE SUMMARY Particulate matter (PM) has been implicated as being responsible for a wide variety of adverse health effects that have been shown in epidemiological studies to contribute to premature deaths (Pope et al. 1995). To formulate effective mitigation approaches, the sources of the PM must be accurately known. Leaf blowers are an obvious source of particulate emissions. The emission rates, however, have never been quantitatively measured and there is no default emission factor in AP -42 for this source. The San Joaquin Valley Unified Air Pollution Control District (District) funded the University of California A Riverside - College of Engineering Center for Environmental Technology (CE- CERT) to design a study and perform measurements and data analysis to determine particulate matter. emissions from leaf blowers and to obtain a PM emission inventory from their operation in the District. This report presents a description of the PM measurement program and the study findings. This - report does not address emissions from the blower motor itself or noise produced by the blower motor. The approach used to measure emissions from leaf blowers and alternative devices (vacuums, rakes, and brooms) was to operate the devices over a measured area in a tent -like enclosure. In this enclosure the leaf blower (or other device) could be used in a normal manner while allowing the PM emissions to be confined for quantification. PM concentrations were measured with real - time sensors. Measurements were made for total suspended particulate matter (TSP), particulate matter (PM) with an aerodynamic diameter less than ten microns (PMIO) and particulate matter with an aerodynamic diameter less than 2.5 microns (PM2,5). The amount of PM produced per unit area was then calculated by multiplying the concentration once it stabilized (when it became uniformly mixed) by the volume of the enclosure and dividing by the area treated. To directly compare the PM emission characteristics of blowing, vacuuming, raking, and sweeping, the surface to be treated in the enclosure was loaded with surrogate debris. To develop the composition of this surrogate material, bulk samples were collected from areas on the University of California, Riverside (UCR) campus where leaf blowing was about to be conducted to determine the mass of soil and vegetative matter present where these cleaning activities are conducted. The test system was then used to measure emissions from leaf blowing over surfaces where leaf blowing is typically conducted and over surfaces where a- surrogate mixture of soil (obtained from the San Joaquin Valley) and vegetative matter was deposited by our staff. A more limited number of emission tests were performed using the natural /indigenous material at the CE -CERT facility in Riverside and at the UC Kearney Agricultural Center in Parlier, CA. Emission factors were developed for the following four categories: 1. Soil origin Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 2 of 63 Revision: 2 January 27, 2006 2. Cleaning tool (i.e. leaf blower, leaf vacuum, rake and broom) on asphalt surfaces 3. Cleaning tool on concrete surfaces 4. Leaf blowing, raking or sweeping for specific grounds maintenance activities (i.e. cleaning grass clipping from along concrete path, gutter cleaning, asphalt parking lot and driveway cleaning, leaf blowing /raking on lawns and leaf blowing packed dirt parking lots) Table 1 is a summary of the emission factors found from these measurements. These emission factors are provided in terms of mass emitted per square meter of surface cleaned. Several significant aspects of leaf blowing operations were observed: There was little difference between blowing and vacuuming with the model that was tested. m Sweeping with a broom on concrete created significant PM emissions whereas sweeping asphalt did not. ® Raking leaves did not generate significant amounts of PM. Table 1. Summary of emission factors. Draft Final Report Page 3 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision, 2 University of California, Riverside CE -CERT January 27, 2006 A leaf blower fugitive dust emission inventory was prepared for the San Joaquin Valley (SJV) by multiplying emission factors by the estimated area subject to leaf blowing per unit of time. Census data was used to estimate the area over which leaf blowers were operated at residences; the emissions at commercial facilities were estimated to be one third of the residential emissions. A survey of leaf blowing operations was made to determine the area and frequency subject to leaf blowing by surface type for each of the ten census categories. The survey also indicated that weekly blower operation was typical except for the winter months when it was generally biweekly. Table 2 presents these annual PM emissions from leaf blowing operations. Please note that only those portions of Kern County within the boundaries of the District are included in the inventory. Table 2. Annual emissions in the San. Joaquin Valley from leaf blowing activities. 2.0 INTRODUCTION Particulate matter (PM) has been implicated as being responsible for a wide variety of adverse health effects that have been shown in epidemiological studies to contribute to premature deaths (Pope et al. 1995). To formulate effective mitigation approaches, the sources of-the PM must be accurately known. Receptor modeling has shown that PM1,0 of geologic origin is often a significant contributor to the concentrations in areas that are in non - attainment (Chow et _al., 1992). Leaf blowers are an obvious source of particulate emissions. The emission rates, however, have never been quantitatively measured and there is no default emission factor in AP -42 for this source. The San Joaquin Valley Air Pollution Control District (District) funded the University of California at Riverside - College of Engineering. Center for Environmental Technology (CE- CERT) to design a study and perform measurements and data analysis to determine particulate matter emissions from leaf blowers and to obtain an emission inventory from their operation in the District. This report presents a description of the measurement program and the study findings. ern - (SJVAPCD _ Fresno portion) Kings' Madera:. Merced i. S.Joaquin Stanislaus Tulare Total PM 2.5 tons /da Y) r (.. ,.... 0.07 _ 0.05 0.01 - 0.01 = 0.02 r 0.05 0.04 i 0.03 0.26 ......... PM 10 tons /day1 .....:......:...::":..,,,.......,,:.:,,:::w:: 0.13 0.09 0 02 0 02 0.03 - 4 0 09 0.08 0 06 0.52 TSP (tons /day) .................. ... ........ ..,.. 0.17 0.12 0; 02 � 0.03 . ,.....,,,,,......... 0.04 . , ,,,,._ 0.12 ... :...............:: .. 0.10 i 0.08 1 0.69 Table 2. Annual emissions in the San. Joaquin Valley from leaf blowing activities. 2.0 INTRODUCTION Particulate matter (PM) has been implicated as being responsible for a wide variety of adverse health effects that have been shown in epidemiological studies to contribute to premature deaths (Pope et al. 1995). To formulate effective mitigation approaches, the sources of-the PM must be accurately known. Receptor modeling has shown that PM1,0 of geologic origin is often a significant contributor to the concentrations in areas that are in non - attainment (Chow et _al., 1992). Leaf blowers are an obvious source of particulate emissions. The emission rates, however, have never been quantitatively measured and there is no default emission factor in AP -42 for this source. The San Joaquin Valley Air Pollution Control District (District) funded the University of California at Riverside - College of Engineering. Center for Environmental Technology (CE- CERT) to design a study and perform measurements and data analysis to determine particulate matter emissions from leaf blowers and to obtain an emission inventory from their operation in the District. This report presents a description of the measurement program and the study findings. Draft Final Report Page 4 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 2.1 Background Receptor modeling has shown that PMIO of geologic origin is often a significant contributor to the concentrations in areas that are in non - attainment for federal PM10 air quality standards (Chow et al., 1992). These geologic sources are generally fugitive in nature and come from a wide variety of activities that disturb soil or re- entrain soil that has been deposited. Botsford et al. (1996) estimated an emission rate for leaf blowers by making assumptions and applying engineering principles. These emission rate estimations have never been validated with actual measurements. Staff at the California Air Resources Board (California Air Resources Board, 2000) estimated leaf blower emission factors using the Botsford approach and the silt loadings determined by Venkatram and Fitz (1998). These silt loadings, however, were measured in gutters of paved roads, which is not a typical substrate that leaf blowers are used to clean. The ARB estimates have also not been validated by experimental measurements. 2.2 Project Objectives The objective of this study is to develop an emission inventory for these sources using measured emission rates. The PM emission rates from typical leaf blowers and potentially lower emitting alternatives under typical actual and simulated conditions were quantified. These emission rates were then used to develop emission inventories for counties in the San Joaquin Valley. 2.3 Scope of Work This study included the following tasks: ® Develop a measurement system for quantifying airborne particulate matter emissions produced during the process of sweeping, raking, blowing or vacuuming the ground from leaf blowing /vacuuming, raking or sweeping activities ® Determine.the range of emissions and particle size (total suspended particulate matter (TSP), PM10 and PM2.5) from leaf blowing /vacuuming, raking and s «7eeping operations over multiple surfaces and cleaning tasks Determine the types and amount of leaf blowing activities in the counties within the SJVUAPCD ® Use the emission factors and activity data to develop an emission inventory of airborne particulate matter from leaf blowing operation within the SJVUAPCD ® Include appropriate quality control and quality assurance activities in the project to obtain a viable set of data and results with known limits on the uncertainties A quality integrated work plan (QIWP) was prepared for this program (Fitz, 2005) and is attached as Appendix A. This QWIP describes the project goals, approach and QC /QA steps to assure that viable results, meeting the project objectives, would be obtained. Draft Final Report Page 5 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 3.0 EXPERIMENTAL METHODS AND STUD' DESIGN The overall approach to measuring the PM emissions from leaf blowers involved operating the devices in a tunnel or enclosed space to confine the emissions while measuring the PM concentrations in real -time with an optical scattering sensor. Development of a suitable test chamber was a key component since no similar type of testing has been reported in the literature. The chamber needed to be large enough to operate the leaf blower for a representative amount of time and yet of manageable size and weight to easily move to various locations. The chamber was operated in a closed mode in which the test device was operated over defined area. Because we needed to determine the total amount of PM generated, we needed to characterize the vertical and horizontal homogeneity of the PM concentrations in the chamber as a function of time to determine when the PM was adequately mixed, but before significant settling occurred. This was accomplished by separate tests in which the PM monitors were either placed along the horizontal or vertical extents of the test chamber. In addition, we needed to characterize the loss of PM from the test chamber since an absolute seal was impractical. To do this we released ethylene gas as a surrogate tracer for the PM and monitored its decay with a real -time analyzer. Once the full - length 20m test chamber was evaluated, we constructed and tested a half - length version that would be more easily moved to determine emission rates under actual use conditions. In order to determine potential differences between various leaf removal practices on different surfaces, it was necessary to develop a surrogate mixture of soil and vegetative debris that would be representative of that found in actual practice. This was necessary so that the test device was the only variable. To characterize the debris we worked with grounds maintenance people at UCR and vacuumed up aliquots of debris that that were'going to use a leaf blower to remove. These aliquots were sieved and weighed to determine the ratio of soil to vegetative debris and the size composition characteristics of the soil. Various soils from the San Joaquin Valley were used to form the surrogate in combination with locally - derived vegetative debris. Testing was conducted primarily at the CE -CERT facility under controlled conditions using a debris surrogate. PM2.5, PMIO, and TSP filter samples were collected during one test run each day to determine the response characteristics of the real -time optical analyzer with actual PM. The remainder of this section describes the development of the approach as outlined while the following section describes the results obtained 3.1 Instrumentation A description of the measurement and data logging instrumentation is presented in this section. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT 3.1.1 Real -Time PM Monitors — DustTraks Page 6 of 63 Revision: 2 January 27, 2006 Real -time total suspended particulate matter (TSP), PMIO and PM2.5 measurements were performed using Thermo Systems Inc. Model 8520 DustTrak Aerosol Monitors. These instruments use impactors to perform the size cuts and the PM concentrations are then determined by measuring the intensity of the 90° scattering of light from a laser diode. The instruments are calibrated at the factory with Arizona road dust (KIST SRM 8632). The real - time data from this project were compared with the mass determinations from the filter collections on a daily basis to cheek their calibration factors for the specific aerosol present on this project. The- - instrument sample flow rates were set to 1.7 L /min. The instruments' time constants are adjustable from 1 to 60 seconds; they were set to one - second for this project. The instruments' zero responses were checked on a daily basis by placing a filter in line with their inlets and noting the responses. ® Real -Time PM Sampler Collocated Testing The DustTraks were collocated in the test chamber and several tests were performed to determine instrument to instrument variability and to obtain correction factors to normalize the responses of the DustTraks to a single reference instrument. These tests included placing surrogate soil material in the chamber, blowing the material to the end of the chamber and observing the instrument responses. The collocated tests were performed for TSP, PM10 and PM2.5 operation. The comparison results are presented in the Section 4. 3.1.2 Time - Integrated PM Measurements using Filter Samplers Filter samples were collected using custom sampling systems designed by UCR for the collection of total suspended particulate matter TSP, PMIO and PM2.5 samples. For the PMIO size - cuts Graseby - Andersen model 246B inlets were used, but modified such that a single filter could be directly attached to the inlet. These filter samplers operated at 16.7 L /min. For PM2.5, size -cut Sensidyne model 240 cyclones sampling at approximately 110 L /min were used to provide the cutpoint. Two sample systems, each consisting of a rotary vane pump, needle valves and rotameters for flow control and measurement and TSP, PMIO and PM2.5 inlets were used to collect samples on filter media at the same two locations that samples were collected using DustTraks. The samples were collected on 47 mm Gelman Teflo filters with a 2.0 µm pore size. A Cahn Model 34 microbalance at the CE -CERT laboratory was used to determine the weight of the filters to within 1 µg before and after sampling. All filters were equilibrated at 23 °C and 40% relative humidity for at least 24 hours prior to weighing. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 7 of 63 Revision; 2 January 27, 2006 The results of this sampling were used to determine differences between the optical DustTrak method of determining PM and the mass collected on filter reference methods. 3.1.3 Wind Speed and Wind Direction Prevailing winds for testing performed at CE -CERT were determined using a wind system located at a height of 5 meters at CE -CERT. A Climatronics F460 wind speed and wind direction monitoring system connected to a Campbell l OX data logger. This system measured and process wind's into ten minute and hourly averages, The system has an accuracy of + \ -5 degrees for wind direction and +1 -5% wind speed accuracy for winds _greater than_5 m /s. The wind - system is shown in Figure 1. For measurements performed at the UC Kearney facility, wind data were obtained from the SJVUAPCD site operated on the facility. The wind system is shown in Figure 2. Draft Final Report Page 8 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 Figure 2. SJVUAPCD wind system at UC Kearney facility. 3.1.4 Propene 'Tracer Gas Measurements The test chamber was not a completely sealed system. We were aware that there would be exchanges and losses of chamber air to the outside. Tracer gas was introduced into the chamber prior to each test run to assess the exchange amount. Approximately 3 liters of pure propene was placed in a bag (Figure 3) and released over the length of the chamber about two minutes prior to each run. Measurements for this tracer gas were performed using a RAE Systems ppbRAB hydrocarbon analyzer. The instrument determines the concentration of hydrocarbons using a 103 electron volt photo ionization detector (PID). The instrument internally records the concentration and time data with a five second resolution. The instrument has a lower detection limit for propene (C3H6) of approximately 50 ppb. The three liters of propene introduced in the chamber created a concentration of about 37.5 ppm (37,500 ppb) for the 20m long chamber and 75 ppm for the 10 m long chamber, which was readily detectable by the PID. The instrument was Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 9 of 63 Revision: 2 January 27, 2006 placed at a height of 2m. It was placed at a distance of 6m in for the 20m chamber (Figure 4) and 2m in for the l Om chamber. The objective of the tracer was to look at the rate of change in tracer concentration with time. As a consequence, it was not necessary to accurately determine the amount of propene introduced into the chamber. The rate of change (i.e. tracer concentration decrease over time) for the propene is a surrogate for the amount of I'M lost from the chamber to the outside due to incomplete sealing of the chamber. The tracer measurements were initially used to help validate the chamber method approach. The initial testing indicated that there was about a 1 -2% per minute air exchange. This exchange was sufficiently low to not impact the chamber measurements. Exchange rates for all runs are presented in Section 3. tracer gas preparation. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 10 of 63 Revision: 2 January 27, 2006 Figure 4. Photoionization analyzer in chamber used to measure propene tracer gas concentration. 3.1.5 Data Acquisition System Data from the eight DustTraks were collected using a PC with LabVIEW software and appropriate RS -232 multiplexers. The logging and averaging periods for each channel will be set to one second. Data from the ClimatrQnics WS /WD system were collected using a Campbell l OX data logger. Data from the RAE Systems ppbRAE propene analyzer were internally logged. At the conclusion of each set of tests, all data were transferred to a networked PC for storage and backup. 3.1.6 Leaf Blowers There are several categories of leaf blowers. For this project, we procured one of each of the Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 11 of 63 Revision: 2 January 27, 2006 following: gasoline powered, Hand held, gasoline powered backpack and electric powered with blower and vacuum capability. We procured these from a home, supply store, We selected the ones that are most popular and most likely of the style to be in use in the San Joaquin Valley.. The leaf blowers used were identified as the most popular from a major supply store (Home Depot, 2005): ® Black & Decker Model BV 4000 Hand Held', Electric Blower/Vacuum (Figure 5)- ® Echo Model PB: 261L Gas Backpack Blower (Figure 6) 6 Homelite Model 30 cc,Vac Attack, II Gas-- ._Hand.Held Blower. (Figure.. 7) )Figure 5. Electric powered hand held blower /vacuum. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 12 of 63 Revision: 2 January 27, 2006 Figure 7. Gas powered backpack blower. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT 3.1.7 Rakes and Brooms Page 13 of 63 Revision: 2 January 27, 2006 A rake and push broom were procured for examining alternate methods to leaf blowers for this study. We procured one new broom (Figure 8) and rake (Figure 9) from a major home supply etnra Figure 8. Push broom used for study. Figure 9. Rake used for study. Draft Final Report Page 14 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 3.1.8 Surrogate Material Spreading It was important to spread out the surrogate material, consisting of soil, grass clippings and leaves in a reasonably uniform manner prior to each leaf blowing run. Initially we tried to use a fertilizer spreader to spread our surrogate soil consisting of soil, grass clippings and leaves along ground inside the test chamber. This method did not work at all for the three items blended. It was also felt that it would tend to segregate the soil by size should we choose to use it just to disperse the soil. We switched to a bucket consisting of the soil, grass and leaves combined. The material was then shaken out of the bucket in the test area. Due to the differences in densities between the soil, grass and leaves, the material did not come out of the bucket in a uniform manner. We then switched to three buckets, one for the soil; a second for the grass clippings and a third for the leaves. This method was used to spread out the surrogate material for all runs. 3.1.9 Triple Beare Balance A model 710 -00 Ohaus triple beam balance was used to weigh soil and vegetative matter used in the tests. The balance had a resolution of 0.1 grams. 3.1.10 Sieve Shaker A model Rx -29 Ro -tar sieve shaker was used to shake the sieves containing samples that were sieved into fractions and weighed. Five sieves were used to separate the samples into six fractions. The sieves were No. 3/8 (.375 inch, 9500 µm), No. 4 (4750 µrn), No 18 (1000 µm), No. 40 (425 µm) and No. 200 (75 µm). Sieving the soil for preparation for use in surrogate soil material was done by manually shaking the sieves. The finest sieve for this task was the No. 40, 425 µm. Soil passing through this sieve was then weighed and used for the surrogate soil. 3.2 Design and Evaluation of Test Chambers Designing, constructing and testing a system for determining PM emission rates from leaf blower operations were the first tasks in the measurement program. Both an open test shelter (tunnel) and closed system (chamber) were considered for this project. The initial plan for the test chamber is shown in Figure 10. A test chamber configuration has. several advantages over the tunnel. A major advantage of the chamber is there is no need to determine the air flow rate through the test apparatus. However, characterizing PM concentration differences throughout the tunnel becomes important as it is a closed system and it is the calculations will be based on Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 15 of 63 Revision: 2 January 27, 2006 accurately knowing the total amount of mass in the air in the test chamber. We initially pursued using the chamber method for the following reasons: • We believed that we would be able to accurately quantify the entire amount of mass in the chamber • It was likely that the higher and more stable concentrations within a test chamber could be more accurately and precisely determined than using a flow - through tunnel. • The chamber method eliminates the need to quantify the air flow rate through the measurement system • The chamber method does not need winds to be present or blowing at any particular speed or in any particular direction The remainder of this section discusses the testing performed to assess the performance and operating characteristics of the chamber method. 1 2 3 4 5 6 7 8 9 1011 12 13 14 15 16 17 18 19 20 20 meters long x 2 meters tall x 2 meters wide Figure 10.20m test chamber. 3.2.1 Twenty Meter Long Test Chamber The first chamber constructed was 2m wide, 2m high and 20m long. It was constructed using 1 inch PVC pipe and aluminum modular pipe and rail fittings. The chamber was enclosed using a polyethylene tarp. Figure 10 is a drawing of the chamber and Figure 11 shows photographs of the chamber. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 16 of 63 Revision: 2 January 27, 2006 Figure 11. Photographs of 20m test chamber. 3.2.2 Initial Evaluation of the 20m Chamber Material was laid out as shown in Figure 12. A leaf blower was used to sweep the material to the end of the structure. Observations were made for the following: • Losses along the length of the structure due to using round pipe at the bottom • Losses under the length of the structure due to non flat surface — integrity between ground and pipe running along ground not maintained • Creation of a copious of dust plume leading to an unsafe work environment • Potential for High of gas powered leaf blower exhaust buildup in chamber leading to an unsafe work environment • Ability /inability to sweep soil due to shape /dimensions of test chamber 1 2 3 4 5 6 7 3 9 1011 121314151617131920 Bulk material for testing placed Leaf blowing performed from 5m to between 5m and 15m and 1 m wide 20m along chamber Figure 12. 'Top view of test chamber showing test material. We found that uneven surfaces may create a problem sealing the chamber along the base. As Draft Final Report _ Page 17 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 shown in Figure 13, this problem was resolved by placing 1.5 inch OD PVC pipe on top of the excess tarp and using sand bags to hold down the pipe and tarp. Figure 13. Addition of pipe and sandbags along base of chamber to eliminate leaks. The range of the dust plume generated within the chamber varied from about 5 ing /m3 to. about 30 mg /m3 (although one test did reach levels just over 1.00 mg /m3). This range was within the 0.001 -100 mg /11,13 range of the DustTraks. (Note: the DustTraks do continue to respond to concentrations above 100mg /m3, but it's beyond the manufacturer's specified operating range.) The ranges of PM concentrations encountered within the chamber were not comfortable for staff to work in. The OSHA. permissible exposure level (PEL) (level that a healthy individual can work in for eight hours) is 10 Mg/M3 and the CaIOSHA level short-terin exposure level (STEL) (level that a healthy individual can -work in for fifteen minutes) is 20 mg /m3. In order to provide a safe and comfortable working enviromnent, staff working in the test chamber used the respiratory protection equipment shown in Figure 14. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 18 of 63 Revision: 2 January 27, 2006 Figure 14. respiratory protection equipment used for chamber tests. The initial chamber was tin wide x 2m tall x 20m long. Most of the work performed in Riverside was done using this chamber. This length was originally chosen so that it would also be suitable for use as a tunnel. In order to have a more convenient size chamber for moving to multiple test locations in Riverside and at the UC Kearney agricultural facility near Fresno, the chamber was reduced in length to 1 Om (Figure 15). Chamber assessment tests were performed on both the 20m and l Om long chambers. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 19 of 63 Revision: 2 January 27, 2006 Figure 15. 10m test chamber. 3.2.3 Dust Plume Characterization Initial test runs were performed using soil from three UC research areas in the San Joaquin Valley, Fresno, Madera and as well as material already present on the ground in the chamber. These tests were performed to check that the.range of airborne particulate matter generated was within the range of operation of the DustTraks. As presented in Section 3.2.1, the plumes generated were well within the operating range of the DustTraks. For the 20m chamber, we laid out surrogate material in a l Om2 area (Figure 12). For the l Om chamber, we laid out half as much material and placed that material in a 5m2 area (Figure 16). Draft Final Report Page 20 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 Figure 16. Photographs showing surrogate material laid out in the 10m test chamber. Additional testing was performed on the chamber to determine its mixing characteristics. Tests were performed to assess PM characteristics along the length of the chamber (horizontal gradients), PM characteristics in the vertical (vertical gradients) and changes in PM concentration with time (time to equilibrium). Material was laid out in the 20m long chamber as shown in Figure 12. The impactors were removed from all eight DustTraks so that they were all measuring TSP. To determine the horizontal concentration gradients of PM, the DustTraks were placed at a height of 2m at the following distances in: 2m, 6m, IOm, 16m, 18m, and 20m (Figure 17). As shown in Figure 18, DustTraks were collocated -at IOm and 16m. A leaf blower was used to blow the material to the end of the.chamber (Figure 19). The DustTrak data were reviewed to determine plume characteristics across the chamber. This test was repeated several times. This test was also repeated with PMIO and PM2.5 inlets on the DustTraks. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 21 of 63 Revision: 2 January 27, 2006 Figure 17. DustTrak locations in 20m test. chamber for determining horizontal particulate matter distribution. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 22 of 63 Revision: 2 January 27, 2006 Figure 18. Collocated DustTraks at 10m and 16m for horizontal gradient tests. Figure 19. Blowing operation for horizontal gradient tests. To determine the vertical concentration gradients of the PM, three DustTraks were placed in the Draft Final Report Page 23 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 chamber at a distance of l Om at heights of 0.5m, 1. Om and 2m and three DustTraks were placed in at 16m at the same three heights (Figure 20). Two additional DustTraks were collocated at a height of 2m at the 10m distances in. The above tests were repeated with TSP, PMIO and PM2.5 inlets to obtain vertical profile data. C 1 2 3 4 5 6 7 8 9 10 11. 12 13 14 15 16 17 18 19 20 Figure 20. DustTrak locations in 20m test chamber for determining vertical particulate matter distribution. A similar set of horizontal and'vertical gradient tests were performed for the l Om long chamber. Four DustTraks were placed at a height of 2m at distances in'of 2m; 4m; 6m and 8m. Four additional DustTraks were placed in at the distances, but a height of lm. Figure 21 shows photographs of this setup. Three test runs were performed with the DustTralcs setup to monitor TSP. Three additional tests were performed with the DustTralcs setup for PMIO and an additional three tests with the DustTraks setup for PM2.5• Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 24 of 63 Revision: 2 January 27, 2006 Figure 21. DustTrak locations in 10m test chamber for determining horizontal and vertical particulate matter concentration gradients. The findings from these tests were used to determine the minimum number and placement of PM samplers in order to perform subsequent tests. These tests also provided data as to the amount of time required following the leaf blowing for equilibrium to be obtained. 3.2.4 Ten Aleter Long Test Chamber Seventy -two runs were performed using surrogate material on asphalt and concrete surfaces using the 20m long chamber. The next phase of the project involved moving the chamber over surfaces that included unswept parking lots, curbs and grass surfaces. We felt that a 20m chamber was unnecessary (the length was originally chosen so that it could be used in the tunnel mode) and that it would be difficult to find locations that could accommodate the 20m long chamber. A l Om long chamber should give results equivalent to the 20m chamber, but it would be easier to find test locations and would also be easier to maneuver from test location to test Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 25 of 63 Revision: 2 January 27, 2006 location. For the evaluation of comparability al Om chamber was constructed from using half of the 20m long chamber. It had dimensions of 2m wide, 2m high and 10m long. Figure 22 is a drawing of the chamber and Figure 23 shows photographs of the chamber. 1 2 3, 4 5 6 7 8 9 10' 3.2.5 Sweeping Patterns in Test Chamber Figure 12 shows the sweeping pattern in the 20m long chamber. Material was laid in a I Om2 area, one meter wide from 5m in to 15m in. The material was blown, raked or swept to the 20m end. For vacuuming runs, the vacuuming stopped at 15m. Figure 24 shows the sweeping pattern in the l Om long chamber for the surrogate material. Material was laid in a 5M2 area, one meter wide from 2.5m in to 7.5m in. The material was blown, raked or swept to the I Om end. For vacuuming runs, the vacuuming stopped at 7.5m. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 26 of 63 Revision: 2 January 27, 2006 1 2 3 4 5 6 7 8 9 10 Bulk material for testing placed between 2.5m and 7,5m at a width of 1m Figure 24. Surrogate material deployment pattern in 10m clamber. Figure 25 shows the cleaning patterns used for the l Om chamber on indigenous surfaces. The I Om chamber was placed along the side of a recently mowed lawn, 0.3m on the lawn and 1.7m on the concrete surface next to the lawn. A leaf blower was used to blow the concrete surface sprinkled with grass clippings over a 9m2 area from lm in the IOm end. The leaf blower was directed to blow material directly back on to the lawn. As shown in the next part of Figure 25, the l Om chamber was setup in a similar manner for cleaning a curb gutter. However, material was either raked or blown from lm in to the l Om end for gutter cleaning. The 1Om chamber was placed over lawns and packed dirt surfaces to obtain emission data from cleaning these surfaces. As shown in the last part of Figure 25, raking or blowing these surfaces was performed over the full 2m width from lm in to the IOm end of the chamber. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT 1 2 3 4 5 6 7 8 9 10 Surrogate material for testing placed between 2.5m and 7.5m at a width of 1 m. Material blown from 2.5m to 10m 0.3m of chamber widl placed on lawn 1 2 3 4 5 6 7 8 9 Concrete side of lawn testing was from 1 m to 1 Om at a width of 1 m. Material was blown directly back onto lawn. I 0.3m of chamber width placed on sidewalk or grass beyond curb 1 2 3 4 5 6 7 8 10 Gutter testing was from 1m to 1 Om. at a width of 1 m. Material was blown to end of 10m test area 1 2 3 4 5 6 7 8 9 10 Lawn testing was from 1m to 10m at a width 'of 2m. Material was blown to end of 1 Om test area Page 27 of 63 Revision: 2 Januaiy 27, 2006 Figure 25. Cleaning patterns for natural /indigenous material ivith lOm chamber. 3.3 Surrogate and Actual Debris Selection, Preparation and Evaluation Some tests were performed by placing the test chamber over a section of surface and blowing, sweeping or raking that ground. Other tests were performed by placing the chamber over a cleaned section of surface (either an asphalt or concrete surface), placing a measured' amount of surrogate material down, then blowing, sweeping or raking that surface, as appropriate. The Draft Final Report Page 28 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 latter work was performed by placing known quantities of material on cleaned surfaces was critical for comparing different types of leaf blowers, raking and sweeping. In order to determine the appropriate amount of surrogate material to be placed on the cleaned surfaces, a series of measurements were performed on soils and surfaces to determine the range of their mass per unit area and soil /vegetative matter ratios. Note: We used the terms "soil" and "vegetative matter" in this study as follows: We used dirt shoveled from near the surface of the ground for the soil material. This dirt was likely fairly rich in organic matter. We use the term "vegetative matter" to refer to leaves, grass, twigs, etc. that are on the surface of the ground (i.e. clippings from recently cut grass or leaves that have recently fallen from trees or been blown into the area). e Soil versus Vegetative Mass Ratio of 'Test Material One -meter square areas at selected locations around the UCR campus where leaf blowers are routinely used were vacuumed just prior to routine leaf blowing activities. Figure 26 shows photographs of several of these areas. The vacuumed material was separated via sieves into six size ranges from greater than about 1 cm (No. 3/8 inch sieve) to less than 75 µm (No. 200 sieve), We had expected a fairly clear distinction between soil material and vegetative matter from the sieving. The soil /vegetative distinction was not as clear between the sieve fractions as anticipated; there was a fair amount of vegetative matter in the finer sieve fractions and some soil material appeared in the larger sieve fractions. However; the sieving did provide sufficient data to determine the mass of soil material and its size (i.e. diameter based on sieving) as well as the mass of vegetative matter to use for creating surrogate samples: Details of the amount of material in each sieve fraction and the locations and types of areas samples were collected from are presented in Section 4.4. Based on the this work we prepared samples consisting of 120 grains of soil (mass after passing through a No. 40 (425 µm) sieve), 60 grains of leaves and 60 grams of grass clippings to be spread out in a 10 in area in the 20m long chamber and half that amount to be spread in a 5m2 area in the 10m long chamber. Draft Final Report Page 29 of 63 PM Emission Factors and Ifventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 Figure 26. Square meter areas vacuumed and analyzed just prior to leaf blowing. Preparation of Surrogate Material Using the soil /vegetative ratio determined above, surrogate soils were prepared using the soils from three UC agricultural experimental facilities (Kearney, Five Points, and Shafter) and that supplied by the District from the Fresno and Madera areas. Separate samples with grass and leaf material were made for each of the soil samples. The material was spread out as shown in Figure 12 and a leaf blower was used to sweep the material to the end. Comparisons of the airborne PM levels were made between'the three UC facilities and Fresno soils to identify any differences. The findings from this work are presented in Section 4.5. For the emissions testing to determine emissions related to different types of blowers, brooms and rakes, only the soil from the UC Kearney facility in the San Joaquin Valley was used as it was desired to have just a single variable, the type of sweeper, for those emission determinations. However, as part of the study to determine emission factors for different materials, we performed significant testing using only one leaf blower to sweep over different surfaces with the indigenous soil and vegetative matter. Additional runs were also performed over indigenous soil and vegetative matter using a rake or broom, as appropriate. Draft Final Report Page 30 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 3.3.1 Soil Silt Content CE -CERT had soil from three agricultural facilities located in three different areas of the San Joaquin Valley from a previous study. These soils were used in the present study. We had aliquots of all of these soils analyzed for silt content using the following two methods. ® AP -42 Soil Analysis Method The current protocol used by most agencies to estimate the amount dust entrained from agricultural tilling and from dirt roads is presented in AP -42 (EPA, 1995). Appendix C.2 of AP -42 describes a dry sieve protocol to determine the percentage of mass that passes through a No. 200 sieve (75µm) and to define this fraction the "silt content." Aliquots of soils from the three UC agricultural facilities in Shafter, Kearney, 5- Points were analyzed by this method. ® Multisize Fraction Laboratory Analysis of Soils Aliquots of the above three soils (Shafter, .Kearney, and 5 Points) were analyzed by methods to provide more comprehensive particle size information (in particular for the —75 micron and smaller size diameters) than is provided by the Method AP -42 protocol. ASTM Method D422 (ASTM, 1990) was used to determine the sand, silt and clay content in the under 75 µm size range. This is a wet sieve method that uses sedimentation of the soil (or a sieved frac tion of the soil) to determine diameter of the soil particles. Aliquots of the three UC agricultural facility soils plus the Fresno and Madera soils provided by the Shafter percent passing) Kearney percent passing) 5 Points (Westside) percent passing Method AP -42: Sieve Number .Sieve Grid Size 20 850pm 100 100 -_ 100 40 425pm 99.5 99.8 99.1 60 - 250pm 85.2 91 91 100 150pm 69.3 78.3 72.5 200 75pm 45.4 60.7 = 37.7 Method D422: - - - Gravel (percent) 0 0 0 Sand = (percent) = 55 = 39 62 Silt (percent) 31 53 28 Clay ( <0.002 mm) (percent) 14 8 10 Moisture = percent = 1.6 1.5 = 1.3 Table 3. Particle size analysis of various soil types used. Aliquots of the three UC agricultural facility soils plus the Fresno and Madera soils provided by the Draft Final Report Page 31 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 District were analyzed as part of this study. They were analyzed by the sieve method described in AP -42, except they were not baked prior to sieving. (We wanted the sieve data to reflect as -is conditions for these soils.) The findings from these analyses are presented in Table 4. To Sieve none .,,, .3/8 inch:,::,, #4 ::::.,,,,. #18 :::.::..: ` :,:,.,.,: #40 :,,::.:, ..:.., #200,,..,,.:,, :: p „j...:, Bottom Sieve" 3/8 inch E #4.,,,,.:,:, #1,8 „ " #40 #200 none ...,,,.,,,. ,....,,,,,..,..,.,.,,,,,,,,,,,, ,,,,,,,,,,,,,,,,,,,.,....,...........,...,..........:.,,,,,.,,,,.,...., ..,.,,,..................,...., i..,......,....:,.,,. .....,.,,....,..,.,............ ,,,,..........,........,.,,,,....,.,,,,,.,,.......,....,..,...,..,.....,.,:,,..,,.,..,...,............,,,..,,..,.... ............................... Bottom Sieve Mesh Size >9,500 pm 1 9,500 pm 4,750 pm 1,000 pm 425 pm 75 pm (percent) (percent) (percent) (percent) (percent) (percent) Kearne 0 1 2 18 47 32 Shafter 0 1 12 22 49 16 ..........:.:... ....... .:....:.....::... . .......:.:............. ...... a „...., ....., .......,,....., ...... Fresno 0 1 ; 18 40 29 11 ,, 5 Points 5 7 24 19 33 11 _ ............................................... ............................... .. Madera 14 7 6 14 45 14 * Sieve Range: Material passed through larger (top) sieve shown, but did not pass through smaller (bottom) sieve shown. ** Bottom Sieve Mesh Size: Value shown is grid mesh dimension of bottom sieve; the dimension that material did not pass through. * ** (percent): this is the percentage of total sample mass collected on bottom sieve except for last column where it is the percentage of sample collected after passing .through the #200,sieve. Table 4. Sieve analysis of the five soils used. 3.4 Data Processing and Validation . 3.4.1 Data Handling All testing was documented in the project logbook. A form was created to log filter data and document chain of custody. Additional forms were created to log collection of the lm2 samples from areas planned to be blown as part of routine leaf blowing operations and logging the mass determined from each sieve fraction. In addition, all periods of data collection, including the specific sampling mode and any known problems with any of the instruments, were logged at a sufficient level of detail in order to preclude misdirection of data. Data collected on the data logging PC were transferred to a networked PC for storage and backup on a daily basis. Power failures, instrument or computer failures, operator intervention for maintenance and calibration, deviation of the instrument calibration results outside the acceptable limits, deviations of the QC checks outside the acceptable ranges, problems with the sample runs, or Draft Final Report Page 32 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 other problems are all factors can potentially compromise data validity. The Project Team identified those periods during which specific data may be considered unreliable by the use of data flags. When these factors occurred it was recorded in the project logbook and communicated directly to those performing the data validation and analysis. The data were inspected graphically and all discrepancies and inconsistencies were resolved by discussion within the project team and /or by reference to the raw data and the project logbook. 3.4.2 Data Validation Data validation followed guidelines described by the U.S. Environmental Protection Agency (U.S. EPA, 1978, 1980). A-11 data were screened -for outliers that were not within the physically reasonable (normal) ranges. Next, the following steps were taken: 1. Data were flagged when deviations from measurement assumptions had occurred. 2. Computer file entries were checked for proper date and time. 3. Measurement data resulting from instrument malfunctions were invalidated. 4. Data were corrected for calibrations or interference biases. Meteorological, propene tracer and DustTrak data were reviewed as time series plots and using computer based outlier screening routines. Rapidly changing, anomalous or otherwise suspect data were examined with respect to other data. Computer based outlier programs were used to screen the data from the eight DustTraks for anomalies (e.g. PM2.5 > PMIo, etc). Data were not invalidated unless there was an identifiable problem or the measurement result was physically impossible. 3.4.3 Data Analysis The filter sampler data were used to develop correction factors between the mass concentrations reported by the DustTraks and the concentrations determined by those determined from the filter data. These correction factors were used to adjust the data measured by the DustTraks for the airborne particulate matter used in this project. Emission factors were calculated for the sweeping activities. We collected data to enable calculation of emissions in terms of airborne mass (TSP, PMIo and PM2.5) per unit area swept, airborne mass per unit time swept and airborne mass per unit mass swept. The emission factors reported here are in terms of emissions per unit area cleaned.. These findings have been tabulated in Section 4. Comparisons of the emission factors were made to better understand variables effecting emissions as well as to perform a level 2 validation of the data. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT 3.4.4 Data Precision, Accuracy and Completeness 0 Accuracy Page 33 of 63 Revision; 2 January 27, 2006 The accuracy of the filter samplers was determined from a performance audit conducted during the study. The audit consisted of determining the flow rate for each of the six samplers and comparing those flow rates to the flow rates used by the measurement team. The percent difference for each of the six filter samplers was calculated using the following equation: %Dif. = [(Y - X) /X] x 100 In this equation, X is the test value and Y is the corresponding instrument response. e Precision The precision of the DustTraks was determined from collocating two additional DustTraks. The differences between the collocated instruments were determined using the following equation: %Dif. = 2(A - B) /(A +.B) x 100 In this equation, A is the value from the instrument A and B is the corresponding instrument value reported from collocated instrument B. A series of replicate collocation checks were assimilated and an average and standard deviation from the entire set of collocated data were calculated. P Minimum Detection Limits The minimum detection limits (MDLs) are defined as a statistically determined Alalue .abo 'Ve which the reported concentration can be differentiated, at a specific probability, from a zero concentration. For this study, the gas an (PID instrument used for measuring propene) and DustTraks were all operated well above their MDLs. 0 Completeness Completeness was determined from the collected data generated during the study using the following equation: Completeness = A, - D,) /D, *100 Draft Final Report Page 34 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 Where D,; is the number of samples for which valid results were reported and D, is the number of samples that were scheduled to be collected. The provisional completeness objective for this study was 90% for each instrument for each sampling run. The data completeness are presented in Section 4. 4.0 Al EASUREMENTS AND RESULTS Measurements to determine emission factors were performed during August and September 2005. This section presents the results from those measurements. 4.1- Sandy Dates and Conditions Measurements were performed during August and September 2005. Development of the test chambers and most of the testing using surrogate soils was performed at the UCR CE -CERT facility in Riverside. Table 5 summarizes the study activities and meteorological conditions. " Indigenous Material Run: Test perofrmed by placing chamber over undesturbed surface and cleaning that surface as described. in Sections 3.2 and 3.3. Table 5. Summary of study activities and meteorological conditions. Measurements of emissions from blowing and raking on surfaces with natural /indigenous material, including asphalt parking lot, grass lawn and street gutter were performed at the Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 35 of 63 Revision: 2 January 27, 2006 CE -CERT facility September 6 -8, 2005. Additional measurements of emissions from blowing, raking or sweeping on surfaces with indigenous material, concrete walkways adjacent to a mowed lawn, grass lawns, asphalt driveways, street gutter and packed dirt parking lot were performed at the UC Kearney agricultural facility in Parlier on September 12 -14, 2005. Our staff followed grounds maintenance crews around the UCR campus between August 9 and 11 and collected 23 debris samples from areas that were about to be leaf blown. Most of the measurement work was performed between 5 am and 2 pm PDT. This working period proved to be best for the following reasons. The UCR grounds maintenance crews complete their cleaning work by about 7 am daily. For test runs we found that the stronger afternoon winds resulted in fairly high air exchanges between the chamber and outside air. Additionally, the higher afternoon temperatures and radiant heating of the test chamber created uncomfortable working conditions in the test chamber. 4.2 Test Chamber Characteristics As described in Section 3.2.2, a series of tests were performed on the 20m and 10m chambers to determine horizontal and vertical gradients and time to equilibrium. 4.2.1 Twenty Meter Test Chamber Horizontal Characteristics Figure 27 shows the responses of the eight DustTraks spaced out at the horizontal distances shown in the legend (e.g. 2M is the D.ustTrak at two meters, 16M -colt = is the collocated DustTrak at sixteen meters). All eight DustTraks were at a height of two meters. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 36 of 63 Revision: 2 January 27, 2006 Figure 27. Time series of DustTrak TSP responses for horizontal distribution characterization. As can be seen in the figure, the DustTraks show some initially high concentrations (greater than 25 mg /m3) during the leaf blowing operation. The high concentrations observed during the leaf blowing are the spikes caused as the leaf blowing kicks up short-lived plumes of dust around each DustTrak. The PM concentrations in the chamber during this period are neither uniform, nor in equilibrium The TSP concentration at all distances (the measured locations within the chamber) rapidly drop to a more common value at the end of the leaf blowing operation. The rapid drop off to similar values indicates the suspended mass within the chamber is mixing and becoming more uniform. The concentrations become fairly uniform at about three to six minutes after the end of the leaf blowing. The concentration continues to drop off at a near constant rate over the next twenty minutes to about half of their values at three minutes after the end of leaf blowing. The tracer gas concentrations, not shown here, consistently dropped off at a rate of about one percent per minute, indicating that very little of the ambient mass was lost due to leaks in the chamber. As can be seen in the figure, although the eight DustTraks do track each other, there are some differences in the concentrations observed along the length. Table 6 shows horizontal concentration profiles (averaged between 6 and 6.5 minutes after the end of leaf blowing) for additional runs with the eight DustTraks equipped with TSP, PMIO and PM2.5 inlets and located at the six horizontal locations shown. As can be seen in this table, there is some run -to -run variability. Because we only had eight DustTraks, and these needed to be divided into two with TSP, inlets, two with PMIO inlets and two with PM2.5 inlets, plus use the 25 �f 20 ®2M ®® End Leaf tM Blowing 6M 1b 1OM �e 0 3 min after x 1OM -Coll OWN 1+1 end blowing )K 16M v 40 ® >K ® 16M -Coll 6 min after end �� '' of leaf blowing + 18M f 5 20M 0 13:41 13:55 14:02 14:09 Begin Leaf Blowing Time (Hr:Mn) Figure 27. Time series of DustTrak TSP responses for horizontal distribution characterization. As can be seen in the figure, the DustTraks show some initially high concentrations (greater than 25 mg /m3) during the leaf blowing operation. The high concentrations observed during the leaf blowing are the spikes caused as the leaf blowing kicks up short-lived plumes of dust around each DustTrak. The PM concentrations in the chamber during this period are neither uniform, nor in equilibrium The TSP concentration at all distances (the measured locations within the chamber) rapidly drop to a more common value at the end of the leaf blowing operation. The rapid drop off to similar values indicates the suspended mass within the chamber is mixing and becoming more uniform. The concentrations become fairly uniform at about three to six minutes after the end of the leaf blowing. The concentration continues to drop off at a near constant rate over the next twenty minutes to about half of their values at three minutes after the end of leaf blowing. The tracer gas concentrations, not shown here, consistently dropped off at a rate of about one percent per minute, indicating that very little of the ambient mass was lost due to leaks in the chamber. As can be seen in the figure, although the eight DustTraks do track each other, there are some differences in the concentrations observed along the length. Table 6 shows horizontal concentration profiles (averaged between 6 and 6.5 minutes after the end of leaf blowing) for additional runs with the eight DustTraks equipped with TSP, PMIO and PM2.5 inlets and located at the six horizontal locations shown. As can be seen in this table, there is some run -to -run variability. Because we only had eight DustTraks, and these needed to be divided into two with TSP, inlets, two with PMIO inlets and two with PM2.5 inlets, plus use the Draft Final Report Page 37 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 remaining two for collocated quality control or as backups, as appropriate, it was necessary to determine locations and methods that would allow us to perform the requisite measurements with these instruments. We performed calculations to determine the error in the data if we placed DustTraks only at 10m and 16m and used the average of readings between those two locations to be equivalent to the average concentration along the horizontal length of the chamber. These calculations showed the error to be 12% or less for the nine test runs. We felt that these errors were within the uncertainties of our measurements; indicating that placing the DustTraks at l Om and 16m and using the average concentrations for each of the three size cuts as the average concentration along the length of the chamber would provide accurate results. Table 6. Concentration data (mg /m3) from tests to determine horizontal gradient in 20m chamber. 4.2.2 Twenty Meter Test Chamber Vertical Characteristics Figure 28 shows the responses of the eight DustTraks at heights of 0.5m, 1m and 2m. Three DustTraks were at these heights at a distance of l Om in and another three were at these heights at a distance of 16m in. The remaining two DustTraks were collocated at a height of 2m and a distance in of 10m. All DustTraks were setup to measure TSP. 21976 21975 852006741 21569 862006771 21955 21668 1 21667 Run Size 2 Meters 6 Meters 10 Meters 10 Meters 1 16 Meters 16 Meters ! 18 Meters 20 Meters 0819 1 PM2,5 1,7 € 1.9 2.4 2.6 2.8 2,2' 1 3.4 3.7 ..................,............,.,,..........,................,,..........,.. 0819 2 PM2.5 ........,.........:..........,• 2.5 .......,,,:....:..........:............,•........•,,,.................::,,...........,....._...:........,..,......,...........,.,.,..........................,:,,........,,.,.....,.,•:.....:..:.,,...............:....,..._...............,...... 1'.7 '2.3 2.6 4.1 = t._........_....,............,....._.,_.......,,,.,.......,.,.........,,.,,..:...;......................,,,...................:.......__ 3.0 j 5.1 ,............,•........,....... 5.2 ......................,......,. .....................................,.:................................._....,.................._..::...........,.........,....................:......_...,,,._................,.......... 0819_3 PM2.5 1.7 1.3 j 1.6 ............,,,.._...,..... 1.5 210 1.7 2.6 = 3.6 0817 1 TSP 2.9 i 3.7 2.5 2.4 2.8 3.7 2.0 1.6 0817 2 TSP 4.5 53 39 3.6 36 4.4 27 19 0817_3 TSP 5.6 6.8 4.4 4.2 4.3 = 4.1 3:6 2,6 0818_1 PM10 7.1 9.9..... 5.6 ..........._ 8. 9.............,. .. .. :...... ... .... .... ............. ....:..... .......6.5...... ... 4.8...... 9,4...... .. 0818 2 PM10 ........ ............................... 5.1 ..... ......,........................ 7,5 .............. . ..r.. 8.0 .?....,...........6.9,......... 6.1 = 5.2 i ............ 6.1' ...................... ....:...... 4.9 .. ................... ..... .................. _...................,........................................ 0818_3 PM10 ............................... 5.7 _................... .....................,......... 6,4 ..... 4.7 7.4 6.3 .....:...... 5.9 5.7 5.0 Table 6. Concentration data (mg /m3) from tests to determine horizontal gradient in 20m chamber. 4.2.2 Twenty Meter Test Chamber Vertical Characteristics Figure 28 shows the responses of the eight DustTraks at heights of 0.5m, 1m and 2m. Three DustTraks were at these heights at a distance of l Om in and another three were at these heights at a distance of 16m in. The remaining two DustTraks were collocated at a height of 2m and a distance in of 10m. All DustTraks were setup to measure TSP. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT 90 80 70 60 M E 50 rn E ®. 40 V) 30 20 10 0 14:02 Page 38 of 63 Revision: 2 January 27, 2006 14:09 14:16 14:24 14:31 14:38 14:45 14:52 Time (Hr:Mn) Figure 28. Time series of DustTrak responses for vertical distribution characterization. The vertical profiles shown in Figure 28 show similar responses to the horizontal profiles discussed in Section 4.2.1. Very high concentrations (greater than 25 mg /m3, up to a peals of just over 75 mg /m3 in this example) are present during the leaf blowing as short-lived plumes pass over the DustTraks. The concentrations drop off rapidly and the concentrations at the three heights and two horizontal locations approach each other at the end of the blowing, indicating that the airborne particulate matter are mixing and becoming uniform along both the horizontal and vertical axes. The vertical profile tests were performed several times in the 20m chamber with the DustTraks equipped with TSP, PMio and P1\42.5 inlets. The results for those tests are shown in Table 7. 14:05 -Begin leaf blowing surrogate — D16colH2 material. .. D16H2 D10H0.5 14:06 - End leaf blowing. D16H0.5 — D10H1 _ D10colH2 14:09 - Three minutes after end leaf — D 16H 1 blowing, —D10H2 D = Horizontal distance in 14:12 - Six minutes after end leaf blowing. H = Vertical distance up colt = Collocated sampler z 14:52 - Forty -six minutes after end leaf blowing. h 14:09 14:16 14:24 14:31 14:38 14:45 14:52 Time (Hr:Mn) Figure 28. Time series of DustTrak responses for vertical distribution characterization. The vertical profiles shown in Figure 28 show similar responses to the horizontal profiles discussed in Section 4.2.1. Very high concentrations (greater than 25 mg /m3, up to a peals of just over 75 mg /m3 in this example) are present during the leaf blowing as short-lived plumes pass over the DustTraks. The concentrations drop off rapidly and the concentrations at the three heights and two horizontal locations approach each other at the end of the blowing, indicating that the airborne particulate matter are mixing and becoming uniform along both the horizontal and vertical axes. The vertical profile tests were performed several times in the 20m chamber with the DustTraks equipped with TSP, PMio and P1\42.5 inlets. The results for those tests are shown in Table 7. Draft Final Report Page 39 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January. 27, 2006 Table 7. Concentration data (mg /m3) from tests to determine vertical gradient in 20m chamber. As can be seen in the table, there is some variations in the concentrations with height and distance in. Because of logistic concerns regarding placing the DustTraks at Heights other than 2m and because the differences in concentration along the vertical were similar to the measurement uncertainty, the DustTraks were placed at a height of 2m for subsequent tests with the 20m long chamber. 4.2.3 Ten Meter Test Chamber Horizontal and Vertical Characteristics Our understandings of the horizontal and vertical profiles in the 20m long chamber were used to simplify the setup and testing of the 10m chamber, For the 10m chamber, pairs of DustTraks were placed at horizontal distances of 2m, 4m, 6m and 8m in. One DustTrak from each pair was placed at a height of 1m and the second was placed at a height of 2m. This setup allowed us to perform vertical and horizontal gradient testing at the same time. Testing of the 10m chamber was performed on a concrete surface using surrogate material. The surrogate material was spread out and blown using the manner presented in Section 3.2.5. Separate tests were performed with the DustTraks equipped with TSP, PM1.0 and PM2.5 inlets. Figure 29 shows a time series for, one of the tests with the DustTraks equipped with PM10 inlets.. Distance 6 Distance 16 Height Height Run Size 0.5M Height 1 M Height 2M 0.5M I Height 1 M Height 2M Height 2M Height 2M 0902 1 PM1.0 6 0 6 9 ' 4.9 18 6 18.4 20 0 20.6 17.2 0902 2 PM10 4.7 5.8 4 1 22 0 22 9 ;...:: 25 T ^ 24 24 1 20 0 0903_3 ................. M10 9 5 11.1 9.0 12.6 12,0 11.1 11.1 9.9 0902 4 PM2.5 2.3 1 3.9 3.4 1.4 1.9 3,2 3.2 2.1 0902 5 PM2.5 1.6 - 3.3 2.7 1 0.9 1.8 2.5 2.9 0902_6 PM2.5 1.9 ! 2.2 1 2.3 1.9 1.9 2:D 2.5 1,8 0902 7 TSP 9.6 11 11.7 11.8 13.3' 9.1 7.5 8.1 7.9 .....................................................:................,...................._.,..................................,........;....................................,.,....,..................................:.....,,....................,,,.....................;...................,......................;..,.................:,.,,.................;.......... 0902 8 TSP 7.8 11.5 11.6 11.3 8.5 8.6 r..,.....................,..........,. 9.8- ......................._....... 9.3 ............................_...... F........................................,,.:.........,............,.......,.....................,................ 0902_9 TSP 7.7 .... ... .......... F....... = .9.6 ... ............ .... ..... ........................................................,......... 9.5 13.5 �....................... �..... 7.3 ...... i......... ... ...........,.... ...... ........ 1 8.1 - �..... s........... 9.0' ....�...................,,..... 8.9 Table 7. Concentration data (mg /m3) from tests to determine vertical gradient in 20m chamber. As can be seen in the table, there is some variations in the concentrations with height and distance in. Because of logistic concerns regarding placing the DustTraks at Heights other than 2m and because the differences in concentration along the vertical were similar to the measurement uncertainty, the DustTraks were placed at a height of 2m for subsequent tests with the 20m long chamber. 4.2.3 Ten Meter Test Chamber Horizontal and Vertical Characteristics Our understandings of the horizontal and vertical profiles in the 20m long chamber were used to simplify the setup and testing of the 10m chamber, For the 10m chamber, pairs of DustTraks were placed at horizontal distances of 2m, 4m, 6m and 8m in. One DustTrak from each pair was placed at a height of 1m and the second was placed at a height of 2m. This setup allowed us to perform vertical and horizontal gradient testing at the same time. Testing of the 10m chamber was performed on a concrete surface using surrogate material. The surrogate material was spread out and blown using the manner presented in Section 3.2.5. Separate tests were performed with the DustTraks equipped with TSP, PM1.0 and PM2.5 inlets. Figure 29 shows a time series for, one of the tests with the DustTraks equipped with PM10 inlets.. 50 45 40 35 E o. o. 30 M U 0 n 25 E m E 20 0 N 0. 15 10 5 0 6:24 6:25 6:26 6:28 6:29 6:31 6:32 Time (Hr:Mn) Figure 29. Time series of DustTrak responses for horizontal and vertical distribution characterization in 10m chamber. Draft Final Report Page 40 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 The above figure shows that the concentration differences between the sampling locations drops off substantially 3.5 minutes (6:28 am) after the end of leaf blowing. The differences continue to decrease over the following five minutes shown in the figure. Also note that the tracer gas concentration is declining more slowly, indicating that particles are settling to surfaces. Table 8 presents the results from subsequent test runs for TSP, PM 10 and PM2.5 averaging the concentration data between 6.0 and 6.5 minutes after completing the blowing operation. Although there was some variability between which DustTrak was highest or lowest for a specific run, indicating incomplete and inconsistent mixing, these data indicate that there was sufficient mixing and repeatability within our experimental error to place the DustTraks in similar locations to those selected for the 20m chamber. For the subsequent test runs, three DustTraks (one each TSP, PMIo and PM2.5) were placed at a height of 2m two meters in; three additional DustTraks (one each TSP, PMIO and PM2.5) were placed at a height of 2m six meters in; and collocated PMIo and PM2.5 DustTraks were placed at heights of 2m six meters in. Draft Final Report Page 41 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision; 2 University of California, Riverside CE -CERT January 27, 2006 Table 8. Vertical and horizontal concentration gradient data (mg /m3) averaged -between 6.0 and 6.5 - minutes for 10m chamber. The average concentrations obtained between 6 and 6.5 minutes after the end of blowing was used to calculate the emissions for subsequent runs. 4.3 DustTrak Calibration Factors As presented in Section 3.1.1, there were two parts for obtaining the DustTrak calibration factors. The first part was collocation of DustTraks. This was done to obtain calibration factors normalizing the DustTrak responses to each other. The second was collocation of filter based particulate matter samplers for one run each day to check the calibration factors for each size range against a reference mass measurement method. Figure 30 presents a time series for the eight DustTraks collocated at a height of 2m and in a distance of 6m in the l Om long chamber for three separate test runs. The DustTraks all had their inlets removed for TSP sampling for this collocated test. As shown in the figure, the test ran up to twenty minutes after the end of the leaf blowing, The first five minutes after the end of leaf blowing were excluded from the analysis to allow, time for mixing and a homogeneous ambient PM plume to be present around the collocated samplers. The average concentrations for the eight samplers between minute five and ten, ten and fifteen and fifteen and twenty were determined. One DustTrak was selected to be the reference DustTrak. The ratio of the reference DustTrak averages to the averages for the other seven were determined. This approach was performed for multiple runs with DustTraks set for TSP, PMio and PM2.5 monitoring. Table 9 presents the calibration factors obtained from these data for the three particle cut. sizes. Distance 2M Distance 4M Distance 6M Distance 8M Run Size Height 1 M Height 21\4 Height 1 M 'Height 2M Height 1 M Height 2M Height 1 M Height 2M 0906 1 PM10 12.7 15 3 11.3 1.0 5 14.9 13.5 t 17.2 12.1 0906 2 PM10 120 11 2 11 7 11 7 14 1 13 4 i 15.6 12.3 0906_3 ! PM10 6.1 7.6 9,3 9.7 12.8 11.5 0906 4 € PM2.5 2.3 1.7 2.4 ` 1.3 1.8 1.3 1.8 1 4 0906 5 PM2.5 1 7 1.9 2 8 ; . 1:4 2.1 1 6 2 5 1 2 0906_6: PM2.5 2:0 1.9 2.6 1.5 3.0 1.8 2.9... ... 1.5.... 0906 7 L TSP 5.9 6.7 5.5 7.5 9.5 8.2 11.4 6.0 :.:.........._.. ::............_...........................................................r...........:............:......_..............,.......,..........................:...{..............................................:.............:....................:.........................................._..................._......................,........... 0906_8 TSP 5.9 5.7 5.8 4.5 7.6 4.7 12.5 ............................... 4.0 0906 9 TSP 9.3 ........_ .................:..................:..................:......................:..................................................__.. a 6.6 10.8 4.4 y..._..............,......._................................._................................. 14.4 4.8 11.7 ............................... 4.2 Table 8. Vertical and horizontal concentration gradient data (mg /m3) averaged -between 6.0 and 6.5 - minutes for 10m chamber. The average concentrations obtained between 6 and 6.5 minutes after the end of blowing was used to calculate the emissions for subsequent runs. 4.3 DustTrak Calibration Factors As presented in Section 3.1.1, there were two parts for obtaining the DustTrak calibration factors. The first part was collocation of DustTraks. This was done to obtain calibration factors normalizing the DustTrak responses to each other. The second was collocation of filter based particulate matter samplers for one run each day to check the calibration factors for each size range against a reference mass measurement method. Figure 30 presents a time series for the eight DustTraks collocated at a height of 2m and in a distance of 6m in the l Om long chamber for three separate test runs. The DustTraks all had their inlets removed for TSP sampling for this collocated test. As shown in the figure, the test ran up to twenty minutes after the end of the leaf blowing, The first five minutes after the end of leaf blowing were excluded from the analysis to allow, time for mixing and a homogeneous ambient PM plume to be present around the collocated samplers. The average concentrations for the eight samplers between minute five and ten, ten and fifteen and fifteen and twenty were determined. One DustTrak was selected to be the reference DustTrak. The ratio of the reference DustTrak averages to the averages for the other seven were determined. This approach was performed for multiple runs with DustTraks set for TSP, PMio and PM2.5 monitoring. Table 9 presents the calibration factors obtained from these data for the three particle cut. sizes. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT 19 5 E q E 0 3 a 2 o' Collocated DustTraks -TSP 6 5 M 4 E E3 E a. tom- 2 1 0 Page 42 of 63 Revision: 2 January 27, 2006 Collocated TSP .v 11:55 12:23 12:52 13 :21 o 0 1 2 3 n 5 5 Time (Hr:Mn) Reference DustTrack (mglm "3) Figure 30. Correlation (all three tests) and time - series plots for eight DustTraks collocated in 10m chamber. 13:50 Table 9. Collocated DustTrak mean response ratios. The collocation of filter samplers were used to check the calibration factors for the DustTraks' optical response to a mass response for the specific soil material used on the project. Figure 31. Collocated DustTrak and filter sampler comparisons. As can be seen in Figure 31, there is significant scatter in these comparison data. The filter samplers were started at the same time that the leaf blowing was initiated. This included sampling during a period prior to homogeneous mixing in the chamber, which will enhance the Draft Final Report Page 43 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 amount of scatter. Hence these sampling numbers are used only to confirm that the DustTraks were providing data in the correct range, not to obtain calibration factors. The data indicate that the DustTraks were providing data within an acceptable range. 4.4 Determination of the Composition of Debris for Leaf Blower Testing Twenty -three samples were collected from areas that were about to be leaf blown or swept. They were collected by vacuuming 1 m2 areas in the manner described in Section 3.3. Fourteen of these were from areas around UCR that were being cleaned by the campus gardening. The remaining nine were from areas around CE -CERT (three samples) and the UC Kearney facility (six samples) that were immediately adjacent to locations where the test chamber was setup to blow, rake or sweep indigenous debris. Table 10 presents the total mass and mass for each_o.f_the six size fractions. As can be-seen in the table, the total mass ranged over two orders of magnitude, from 2 to 377 grams. The mass in each size fraction are presented as percentages in Table 11 to more readily identify the differences between the size fractions and to compare samples from one location to the next. Table 10. Mass per sieve size for samples collected from area to be leaf blown. < #40, > i > 318 _ < 3/8, > #4 <94,>#181 <#18,> ! #200 < #200 Total Mass) fraction fraction fraction #40 fraction fraction ! fraction Sampled Location_,` SampleDescriotion„ T_.,._,T - (.grams (grams) _mm (grams) (grams) ( (grams) _(grams) Grams) 1 UCR Asphalt Driveway General cleaning._ , s .377 3 2.8 24.8. 136.5 74.2 104.8 34.3 2 M Concrete Walkway.... Lawn trimmings 49.5 0.9 0.5 8.3 323 4.8 2.7 3_ UCR Textured Concrete; Walkway Lawn trlmmmgs .....,.. 10,4„ '. 0.4 .... ........ 1 1 5 0 2 5 1.1 0.2 4 UCR I ....,....... Concrete Walkway„ Generalcleaning ... 36 1 99 8.8 j 14 6 .1 9 0,8 ; 0.1 „Brinks „ General cleaning , .... 55 2 11 5 19 6 12 3 5 4 4 9 i 1.5 UCR Concrete Walkway- General,cleaning,,.. 242.. ..... .11.9 ,,., ..,., �:3..... 15...... 1 .. J. .... 0.8..... 12 _..... UCR..... ............. o re e a kwa - General cleanfn C....nc. t W.._I Y........ 9.. ............- ..,.......... 10,8 ,......................._..._....;.......,.............................:...-...........,.................;..................................... 0,5 0.5 4.4 i....................................,........-............,............ 1.3 2.5 ...................._.......... 1.4 13. ± UCR Concrete Ste s - General cleanfn P ................... ................... ...g............. .............; 16.2 6.9 2.9 3.6 .................. 1.5 ................... 1.2 .......... 0.2 ........... 14 ! UCR Concrete Walkwa - General cleanln Y 9 ... 4.6 I 1.0 ........ ......... 0.7 .......... 0.5 0.4 ........ 1.4 ...... ....... 0.6 15 i UCR ..... .., .._... Concrete Walkway -Lawn trimmings. _,..,...- .,...._. 14.6:..___., . ....2.8 _.._ 1.2.,,_.. ..... ........ ; ,,,,_,,.6.4 .,.., ..._. 3.2: 1.1 ........ ..... . 0.0 Concrete Walkway_ „ -,Lawn trimmings,,, 12.1 _. 13.0„ 4.0 ( .......... ...... 1.;5 0.1 ..,,._ 21 .... ,UCR ' F ....._. Asphalt Parking Lot Lawn trimmin s 9 ....... .. ........ 26 2 ......... 1 9 3 6 17 3 3.1 .... .......: .......... 0 2 ..... _; 0 0 ....... ... 22 _....... f UCR s. ..._ ........................... .................. Concrete Walkway -Lawn trimmin' s ' .......... ................... . ....................Y.......... .................. ,.g.........,.,...... 2.3 ....... a .................. 0,0 ................. D.2.... . ............................... i ....0.9 .. 08: 0:3 ..... i 0.1 23 I UCR a ............................... Concrete Walkwa - General cleaning ..,,,,,, ... Y.,. ., ,,, ...: 22.6 '' .... 4.3 4.3 ...,.. ,,.. 6.2.,,,,, 8.8 ... 2,3 ..... 0.7 0.2 24 , CE CERT ' « ................................ A.......................................................,......... s a Lo - General cleanln A ph It Parkin .. t 9 ............. g......... ...............:......:....._.. ............ Z5.2. . �......................................:..... 9.4 11.2 �.......-_..............,........... 13.5 ...............,............... _...........,.............,. 12.1 ......_;....................... 20.8 8 2 ... ..... .,........... 25 Leaves and debris............. '..... 109..x..........1_. 0.0 4,3 34.9 37.1 26.1 7.2 26 .. CE -CERT i .................. ..Lawn .................. Gutter... Debris............ ...... 30:9 .... 9d6....... ! 7.9 .... 7.5. .. .. . 3.5...... ..................... 27 s.....,.._......,................,.....,................................... ! Kearney .........,...........�,........ .....,....... ............ .,.,........, Concrete Walkway. Lawntrimmings._ y,........ ..,...._.... _'...........0.3.........'' ; 2 8' ........- ....r...... 0 0 .......:1 ............... ,......... ! 0 0 ......... .....�... 0 4,,, i. ...... ,....., ...... 0 5 ...................... 1 8 ..._.... ... 0.2 . 28 P Kearney Gutter Debris ....... 96 8 0 1 . 3.2 19.8 29 6 42. 2 0 29 ...................__.................... j Kearne ' Y.....:......................................._-.........................................................................................................................................._...............................................,........................................................._...........'.................................... Law - Leaves and debris n 5.0 0.0 0.0 :. 1.1 2.3 i.... 1.6 .....- ......................... i.... 0.1 ............................... 30 I Kearne ? t ..................Y, > ........ As halt Drivewa - General cleaning . ..., p., ............ y... ...... ............ ...................,.........._ l; 12.2 0.0 ..... 0.7 .....,........... .. 3.4_. ....... 2.7 ' ............ 4.3 1.1 .. 31 I Kearne Packed Dirt and Gravel Parking - General cleaning Y ? 50.0 21:6 6.5 8.0 5.4 ' 6.3 2.3 W.32 ..__t W Kearney _..._... ._.. Lawn . Leaves and �debris _.. . _35.0 .. 9..1. 4.1 1 ._.._ 7.7 ...__. 4.2 1 9.1 0.8 _. W,3 .w .......... ........ _ . ..... ... ...... ... .. Average {._ . 48... .:. .. 5 . .. 5 ........ ... ,.. 14 10 11 ..... ... ..... . ....................., E................,.......................................... Minimum .................. ..............., ... ..._ ............... :.. .......... 0 .......... ... ..... I. ...... .. 0 .. ... 0 ................ ........... i Maximum 377 22 25 136 74 105 34 ............ t ....... Median _, _,?6 2 ` 3 8 .... .. 3 2 . ... 1 Standard Deviation 77 6 6 28 17 23 7 Table 10. Mass per sieve size for samples collected from area to be leaf blown. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 44 of 63 Revision: 2 January 21, 2006 Table 11. Percent mass per sieve size for samples collected from area to be leaf blown. Our initial results from this work was used to determine the surrogate soil blend used for this project; 12 grams of soil (weighed after passing through the #40 sieve), 6 grams of grass < 3/8, > < #4, > < #18, > < #40, > > 3/8 #4 #18 #40 #200 < #200 fraction fraction fraction fraction fraction fraction Sample (percent) = (percent) (percent) (percent) (percent) (percent) 1 1 7 36 20 28 9 2 2 1 17 65 10 5 3 3 11 49 24 11 2 4 27 24 40 5 ?_ 0 5 21 35 22 10 9 3 11 49 30 6 4 7 = 3 12 5 4 41 12 24 13 13 42 18 22 9 8 1 14 22 15 11 8 31 13 15 19 8 43 22 7 0 16 33 16 35 11 4 0 21 7 14 66 12 1 0 22 0 10 38 37 13 3 23 19 27 1 39 10 3 1 24 13 15 18 = 16 28 11 25 0 4 32 34 24 7 26 1.111, 1 7 31 2G 24 11 27 0 1 14 18 62 6 28 0 3 20 31 44 ?_ 29 0 0 21 46 32 1 30 0 6 28 22 35 9 31 43 13 16 11 13 5 32 26 12 22 12 26 2 Average ............ .......... 15 ._...........1.2 29 20 19 5 Minimum 0 0 6 4 1 0 Maximum 49 35 G6 65 62 13 Median 7 11 28 16 13 3 Std. Dev. 16 10 14 15 15 4 Table 11. Percent mass per sieve size for samples collected from area to be leaf blown. Our initial results from this work was used to determine the surrogate soil blend used for this project; 12 grams of soil (weighed after passing through the #40 sieve), 6 grams of grass Draft Final Report Page 45 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 clippings and 6 grains of leaves all per meter square of surface. The mass passing through the #40 (425µm) sieve is the equivalent to the sum of the masses in the right two columns in Table 11. As can be. seen, in Table 11, the average mass that passed through the final two sieve stages was (11 +3) 14 grams. The average amount of material that did not pass through the 425µm sieve was 34 grams, considerably more than the 12 grams total of grass clippings and leaves that we deployed per square metes: for our surrogate. However, since our main purpose for this vegetative matter (which is not directly a source of TSP, PMjo or PM2,5) was to provide a target for our leaf blower, placing too little or too much of this coarse size material down does not affect our emission factor results. 4.5 Emission Factor Measurements Our test chambers were used for eighty -five tests using surrogate material and thirty-two tests over natural /indigenous material surfaces. Three different leaf blowers were used, one leaf blower was configured for vacuuming for several tests as well as for blowing mode, a push broom was used for several runs and raking was also performed for several runs. Table 5 shows the number of test runs by date and location. Table 12 presents the test run information by cleaning operation, cleaning implement and location. Draft Final Report Page 46 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 *Material: e.g.: " Shafter <425" is the fraction of soil from Shafter that passed through a sieve with 425 pin openings; "120 +60 +60" indicates 120 .-of th sieved soil, plus 60 g of grass clippings and 60 g of leaves were deployed for the cleaning; and "'/ 1 C31-16" indicates that 0,5 liter of propene tracer gas was released in the chamber ** DustTrak: e:g.: "3 sizes at D = 6, 16" indicates that DustTraks for all three size fractions (TSP, PMIO and PM2.5) were in the chamber and one set of TSP, PMl O and PM2.5 were placed at a distance of 6 meters in and a second set was placed at a distance of 16 meters in. Table 12 (part 1 of 4). Summary of test run conditions and equipment. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE-CERT Page 47 of 63 Revision: 2 January 27, 2006 Table 12 (part 2 of 4). Summary of test run conditions and equipment. lime of Run Number Material Surface I Blower DustTrak cle 1 Run=r I In 11-og a Run 0830 1 Kearney <425; 120+60+60+ 2.5C3H6 ... concrete .. . . concrete . ............. Eloc Blow . .. . 3 sizes at D=6,16 .. ........... ... ........ .. ..... .. .... .......... . ............ 33 S ... .. ...... 6:21' 0830 2 Kearney, <425 120+60+60+ 2.5C3H6 .................................. . ..... . . ............. concrete ..... . ..... .... . ..... ................. Elec Blow . ..... ..... . . ........ . ........ 3 sizes at D=6,16 . .... ..... .......... 35 2 ..... ............ 6:48:30 0830 3 Kearne <425 0+60+ 2.5C3H6 Elec Blow 3 sizes at D=6,16 35 3 1 7:11:50 06304. 4 2.5 3116 3 sizes at D=6.16 ...... .. .... .. 1 35 4 .............. 7:34:25 . . ...... .. . .. .... 0830 5 Kearne <425 120 +60 +60+ 2.5C3H6. concrete Hand Gas ............ Gas....._` 3 sizes at D=6,16 .. ........... 00 ....... ........... .......... ... 0 7:5726 .. .................. ..... ......,?, ._ concrete 1 .... .... ......... Hand Gas ......... ............ .......... 3 sizes at D=6,1 6 sizes .......... 35 6 ............ ..... 8:25:10 .... . .. ......... ..................... 08307 ........... .... .<425120 +60 +60+ 2.6C3H6 !�Y . .... ....... ........... __ ............... ........... concrete . ............ .... ........... Hand Gas .......... 3 siz ........... ........... . 36 .......... 7 9:05:38 ............ ................ I .............. ........... J 9:134:.2-81, 0+60+ 2.5C3H6 ...... .. ... concrete,;,,., . .. I . . ......... ........ ... 9 9;57:40 .... 0830 10 Kearne <425; 120+60+60+ 2.5C3H6 .......... 1.1111 .. ......... .......... ....... . ... . ............ 3 sizes at D=6,16 . ... ................ ....................... 1 _37_ 10 10:21:40 .. ........ ... ... ... 120+60+60+ 2.5C3H6 ... ... ..... ............... ....................... .......... j Backpack ........... __ .. .... . ........ ..... .. ..... 3, . ............. ..... 37 ........... ...... 11 .. ..... 10:66:24 .. ... .......... . 0830 1.2. ............ 2.5.9.3..H.6 ......_._L. concrete .. ........ ... . .. . ...Backpack.......'.. . ... 3 sizes at =6,16 ........... ... ........... .......... 37 12 11:26:05 0831 1 Kearne <425; 120+60+60+ 2.5C3H6 ......... . .................. ..... . ............. concrete 1 Broom ............ 3 ... ............. 6:01:20 . ............ 0831 2 Kearne y 0+60+ 2.5C3H6 ............ concrete 1 .......... ...... Broom ; . ............. 3 sizes at D!�, 16 .................. . . ........... 1 39 .......... 2 0831 3 ........... .. K a 120+60+60+ 2,6C3H i concrete ................. Broom ................... . ..... 3 sizes at D=6,16 ........... . ......... 41 3 . . ..... 6:55:37 .................. 0831 4 2.5C3H6 ....... .......... . ....... ..... .. ....................... . ........ . . ......... .... concrete ......... .. S� ...... ...... .... Broom ...... ............ ............. . .. . ... ............ Al ......... .. ............. .... 7:16:07 . ..... ...................... 0831 5 .... K me <425 120+60+60+ 2.5C3H6 Y ........ . ..... . . . ...... .. Rake ...... .... 3 .. . ........ 7:41:31 0831 6 2.5031-16 concrete Rake .............. 3 sizes at D=6,1 ......... .. 41 6 8;02:1,8 0831 7 ....... . .......... .............. Kearne <425; 120+60+60+ 2.5C3H6 ......... . ................... .... ...... concrete i . ........... Rake 3 sizes at D=6,16 7 i 8:22:38 0831 8 Kearney .<4 §j I2q+ 0+60+ 2.5C3H6 concrete Rake .......... ... ....... 3 sizes at D=6 16 . ....... ......... ................ ... ........... 41 . ......... 8 ......_., 8:9:68 „_ 4......... . . . .......... 0831 9 ...... 120+60+60+ 2.6C3H6 ..... n��92Y �4M .... . ....... . ..... . ................. .. . .......... .. .. .. . ..... i concrete Elec Va 3 sizes at D=6,1 ......... . . . .. ... ..... j; 9:12:44 0831 10 K concrete 3 sizes at D=6,16 .......... ................... 10..,,,,,,.,,,,`,_9;37.29 . ...... 0831 11 ........... 2.5C3H6 .......... ........... ..... . ..... ................... . . ............... . .... ....................... ..... ..... concrete .......... . ..... .............. Elec Vac .......... 3 sizes at D=6,1 6 ... . .................. .. . .... 43 ....._'_.........:..._1:1. ......,.......`..._10:01:1;1... 0831 17 Kearne <425; j��q+�9+60+ 2,5C3H6 ....... ..... ........... I f . ....... 3 sizes at D =6;16 . ...... ..... ................. 43 ............. ._I� j 10:28:43 . ..... ............ 0831 13 . ... .. . ... ....... Five Points <42 120+60+60+ 2.5C3H6 . .......... ............ .......� ... ........ _�.................. ..... ................ ...... ...... .... . . ............ ... concrete Elec Blow . ......... ....... 3 sizes at D=6,16, ......... . . ..... . _,43 13� ........... i,, 10:57:10 .... .......... 0831 14 .... . . ...... .... . ..... Five Points <426; 120+60+60+ 2.5C3H6 ..... ...... . ...................... 1.11, . .......... .......... . .......... concrete 1 .......... . . ................ Else Blow .. .. . ... ................... 3 sizes at D=6j.6 ..... .. ... ..... . _JA ........ . .... 1.1:21:33 0831_15 ............ Shatter <425; 120+60+60+ 2.15C3116 ...... ... . ....... . ............. ..... .... i concrete 1 . . .... Elec Blo w ........... 3 sizes at D=6,16 .................. 43_ 1 6 0831 16 Kearnay concrete Elec Blow j 3 sizes at D=6,16 43 16 12:65:04 0831 17 Kearney <425; 120+60+60+ 2.5C3H6 concrete. Elec Blow 3 sizes at D=6,16 43 17 12:06:31 Table 12 (part 2 of 4). Summary of test run conditions and equipment. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE-CERT Run Number 0902 3 K r ey 120+60+60+ 2.5C3H6 !�qp I ... ....... ........ 11 ......... ................... ...... 0902 4 .. . . ............... . Kearney < 425; 120 +60 +60+ 2'.6C..3,H6 .... ....... 0902 5 ...... ............. Kearney <426;.120 +60 +60+ 2.5C3H6 ............. 0902 6 ....... ....... 12, 0 6 0 69. .......... 2.. 5, _C. 3-H. 6 .... ............. . ..... <425; 120+60+60+ 2,5C3H6 ._ ... ... .... .. _ 0902 11 ................ ................... ..K rney�4?�f240 ..... . ..... .. ... ....... 0902 12 Kearne <42 ............. ............ .. ........ ... 2 0902 14 Kearney <425: 2500+ 2.5C3H6 Above runs are 20m 60+30+30+ 2.5C3H6 60+30-F30+ 2.5C3H6 ......... ... ........ .............. . ...... 47 ..IT!t Driveway ±0 jTSPatD=6,16andH=.5j,2i .... ...... . . ................... . ... ................. 47 4 Asphalt y + 2.5 C3116 ............ 11. 1 .............. 47 Asphalt Driveway + 2.5 C3116 * , - , - - *- !L_L�* Lawn at CE-CERT + 2.5 C3116 45 PM10 at D =6,16 and Elec Blow H=.5,1.2 45 ........... .......... .... .......... PM10 at D =6,16 and Elec Blow H=.5,1,2 47 .... .............. ... ................... ... ............... ...... ... PM2.6 at D=6,16 �nd Elec Blow ............. i TSP at D=6,16 and H=.6 1,2' ...... ............ ....... .! .......... 47 Elec Blow .......... jTSPatD=6,16andH=.5j,2i .... ...... . . ................... . ... ................. 47 Elec Blow D=6,16 and H= .5,1,2= 47 ... ............................ Elec Blow 3 sizes at ...... . . ....... ..... ..... . . ..... Elec Blow Filter 49 . ............... .... . .. . .. .. ................ Tg fa �i b=i6,i�d H=2 + 3 sizes at ElegBlow i Filter ... ............ PM10 at D=16 and H=2 + . Blow Filter 51 _Elec ............ 11 . ..... PM10 at , D =16 ard ............ Elec Blow Filter i 51 Pag at D =16 and H=2 Elec Blow Filter ........... ............ PM2.5atD=16andH*=0+**)... Elec Blow ........... .. Filter . . ........ . . ...... . ........ . ... ...... ........... . . ..... ........... - — ---- 51 . .. . ...... . .............. . ........... . ... ..... PM 10 at D=2,4,6,8 �6& Elec Blow H =1,2 63 .......... PM10 at D=2,4,6,8 ii�d Elec Blow H=1,2 63 ... . . .. ............... PM10 at D= 2,4,6,8 and Elec Blow H=1.2 53 Elec Blow s TSP at D= 2,4,6, Elec Blow ' .... . ......... . . ....... TSP at D=2,4,6, ... ............. . ..... . . ......... Elec iTSPatD=2,4,6, ......... ..... ............... Elec Blow 3 sizes at ........... Elec Blow J ................ 3 sizes at ....... ........... . ........ - Elec Blow 3 sizes at ...... . . ....... ..... ..... . . ..... Elec Blow .... ....... ... ........... 3 sizes at ............... Elec Blow .. . . ... ............ 1 3 sizes at ........... . . ................... i Elec Blow 3 sizes at .......... 56 55 56 and H=1,2 65 and H=1,21 56 .... . ... ... and H=1.2-1, 55 Table 12 (part 3 of 4). Summary of test run conditions and equipment. 67 Page 48 of 63 Revision: 2 January 27, 2006 3 : 7113:32 ................ ... 4 ...... ........ 7:34:27 .......... 7:62:08 6 ........ ... 8:10:44 7 8:29:07 8 8:48:10 ............. . . .... 9:07:11 10 9:48:32 ........... . . 11 10:09:43 .............. .. ........ I .... ......... 12 10:47:20 ........... 13 11:13:24 14 11:46:48 ..... ........ 15 12:11:24 3 8 8.43:17 9 9:02:18 . ........... 7:43:02 ........... . ... ................. . 2 8:27:43 5 9:53:40 Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE-CERT Page 49 of 63 Revision: 2 January 27, 2006 Lawn Lawn Run Number i Time of .9tCE-CERT+2.5C3H6 .",', ............. ...... Asphalt Log Page! In logbook Run lec Blow i gy4T ..... ... ............ . ............ . ..... Asphalt 09013 9„ .. ............. Gutter at CE -CERT + 2.5 C3H6 ouster AIM-- 12:01:07 concrete 0913 2 on con erne 2.5 C3H6 Grass cli in Crete at Ke 'concrete 0913 3 Grass cli in on concrete at K 3 sizes at D=2,6 ................... .. ....... 0.9,1.3-4-- ..-Grass clppin ..on.con rete.at..K arnev+2.5C3H6 ................... ..... ............. 1 concrete ................... 0913 6 . . ........... Gutter at Kearney + 2.5 C31-16 ... ............ . . ........................ . .... ........ ..... ...... . ......... 65 ....... ... IF ... . .. .. ........... ........... .......... . ...... ........... ............. lec Blow F 3 sizes at D=2,6 .............. ....... . . . ..... Gutter at Kearney + 2.5 C3H6 ,y asphalt 0913 8 . ...... ...... . ..... Gutter, at K rn y,±�.5.,C H ea Y� .. ............ 3 sizes at D=2,6 ..... ...... 10 .... .. ............... ............ . ............ asphalt :lec Blow ........... .......... qqt!qra! Ke m y ...... .................... asphalt ........ 4 8:19:20 concrete I .. ................ Qqj3 _12 ...... .... . Gra.ss..P#129199 on cony.re,t.e at..K.e..a.,rney.± c2fl9r.q.t.9 8:69:30 ............ Lawn at Kearne 2.5 C3H6 Lawn 65 ,,,,, „,,,,,,,,,,,,,,,,,,,,,,,,_Lawn 1331-16 ........... ...... .... . ......... LA j!. Tqy ..- Lawn...,., L,a.wn 09141 Asphalt l7riYewayat Kearney+ 2;5 C3H6 ................ asphalt PP14 As h It,Drive y.atj�Mey±.?..5 jp3l-1 .......... ....... ........... P 9-1- �..)n asphalt„ 0914 3 ....... ... J_ 8 0914 4 Kearney <425: 60+30+30+ 2.5C3H6 I asphalt Page 49 of 63 Revision: 2 January 27, 2006 Blow IT. 159_1 69 3 7: 2:00 .......... . ............ . ... ... 0914 6. .. ...... ... ... . ........... ��P412rin atK a + 2 5,(; Y ........ ..... . . ..... ......... ... ....asp 1. .1 1 Run Number i Time of Blower DustTrak Log Page! In logbook Run lec Blow 3 sizes at D=2. 6 ... . ......... . .. ...... .... :-a . . .......... . ... ........ 59 7 i 11:20:40 4 . 3 sizes at D=2,6 at D=2.6 + filters 59 i 8 12:01:07 As halt Driveway at Kearne + 2,5 C3H6_ .. ........ . .. ............ . .... ............ �73 ....... ... ............ lec Blow . ............... 3 sizes at D=2,6 ................... .. ....... I 69 .. . ...... ... 9 12:26:25 _sec Blow . ....... 3 sizes at D=2,6 . ........... 65 ....... ... IF ... . .. .. ........... 15:bU:56 lec Blow F 3 sizes at D=2,6 .............. 65 2 ........... . ........... . ...... 7:15:20 3 sizes at D=2,6 ................. ..................... ........ ........... 3 sizes at D=2,6 ..... ...... 10 .... .. ............... 3 .. ....... . —, ...... 7: 8:44 ....... . .......... . :lec Blow ........... J 1 65 .... ........ 4 8:19:20 rake 3 sizes at D=2,6 . .. .................................... 5_ 8:69:30 ............ 216 65 b j 9;21:15 .......... ............ _sec Blow 3 sizes at D=2,6 ......... . . ..... 65 i 9:40:44 Rake 3 sizes at D=2,6 ...... ................... ............ 65: J_ 8 10:28:07 ...... Packed F- 3 sizes at D=2,6 + filters ............ . ............ 67 ... ........... 9 11:07:34 Hlec Blow i 3sizes at D =2,6 67 ......... ........10 ... . . .. 11:29:11 ..... - Broom 3 siz ... . ......... 13 ... ... 1 12:07:48 ....... ... ... . ...... .. Broom sizes at D= 67........... . 1. 12 :12:26:04 ec Blow 3 sizes at D =2 67 ...... ...... .... 13 1.04'.29. 3 .......... =lec Blow ........ ........... ... 3 sizes at D=2,6 .................... .......... ....... ......... 67 14 ........ . . ... .......... I ... 13:23:26 %c Blow 3 sizes at D=2,6 69 1 1 6:42:24 Blow IT. 159_1 69 3 7: 2:00 .......... . ............ . ... ... 0914 6. .. ...... ... ... . ........... ��P412rin atK a + 2 5,(; Y ........ ..... . . ..... ......... ... ....asp 1. .1 1 Elec Blow . ......... �j sizes at u=4fj ........ ...... ........... . ..... ... .. ........... .... ...... i ti ................. ....... ....... ............. 6 �_.9:04:40 T ........... 3 sizes at D=2,6 71 1 7 ........... 09148 As halt Driveway at Kearne + 2,5 C3H6_ asphalt i _ftRT . ......... 3 sizes at D=2,6- ............... �73 ....... ... ............ . 8 ........ .... ...... i10:04:42 .......... ... MO ...... .. ....... .... Asphalt or! ew a Kear Y ay . .... . ... .... .. 't� t ......E..l. .. ec Blow I . sizes a. t D=2;6 . ....I . .. .. . ....73 .... .... . .. t ........ 9 . . 10:27:39 .. ... ... 0914 10 ............. ...... ........ 2.-5--'C'3'.H.'6'-- .............. .. Lawn 3 sizes at D=2,6 ................. ..................... ........ ........... f 73 .... ............ .... . .... . ............... 10 .... .. ............... 1,11:06:20 ..... . 0914 11 17A Lawn Elec Blow 3 sizes 6t D=2,6 . .. .. ......... ... 11 11:22!44 . .. .................................... Packed ! ........... ....... ............ ........... 0914 12 Packed Dirt Parkin Packed Dirt .......... . Ele�. �lq i 73 .......... 12 11:59:38 ..... .. .. .......... ... .... . ..... ...... Packed F- i 0914 13 ............ ” . . . ............. Packed. D Parkin Lot+2.6C3H6 . . .... 9 ...... .... ......... ... ..... ............... Dirt ec Blow 3 sizes at D=2,6 75 ............. " ... .. . .......... 13 ... ... Table 12 (part 4 of 4). Summary of test run conditions and equipment. Draft Final Report Page 50 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 4.5.1 Measurement Locations The bulls of the testing was conducted in Riverside at the UCR CE -CERT facility using the surrogate debris mixtures consisting of vegetative matter and soil from the UC facilities in the San Joaquin Valley and that supplied by the District, as discussed in the previous section. The 20m test chamber was used to perform most of this surrogate testing on asphalt and concrete surfaces.. Figure 32 shows the chamber locations for these tests. Figure 33 shows the inside of the chamber during several of the test runs. Table 13 lists the tests and the concentration data taken at six minutes after the end of blowing for these runs. Figure 32. Photographs showing 20m chamber for surrogate tests. Figure 33. Photographs showing inside of 20m chamber during testing. Draft Filial Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE-CERT Page 51 of 63 Revision: 2 January 27, 2006 Table 13 (part I of 2). Emission test airborne particulate matter concentrations. Distance A Distance Clean Clean I Clean Area Time PM 2.6 PM10 PM 2.5 PM 2.5 PM10 0 PM1�3) T P �(ma/SW3) Chamber Materlal Blower Locatlon Pattern (m'2) ( (Mg'�) ;� I Mg/M43) Mg/MA3) 3) (mg/m'3)1 (mg/m 20 M ... 0.0 1.6 1 j_ 6.6 0823 2 . ..... Al .. ........ A 10 ...............2.1..:.......x., ..... 01:10 ...... ......4:9....,....5.........0.0 1.6 5.6 .2 9.3 10.6 0824 1 A 7 At 00:48: 0,7 j 2.91 3 7.9 j IT:;I 11 9.1 0 F!_&I RM A 10 02:18 .......... .... ..... 0.7 . ....... __jl 1 2. ...... .... . 1 4:9 T 1.1 0.7 _.�! 1 ..... za� z:3:.:.... +..:......6.0........ ............ 6824 3 Al IL A . _ Al 1.11_..... A _111 1.11.11 ... 10 01:20 ... ...... 1.0 ... ...... . . ......... &.4 .... ....... . . .. 5.4 .......... . i ! 1A., ...... 1 1 ........ 8.2 _6 ..... Or4 A ..... .. 20M ........... .......... .. . . .......... .... ......... ........... . .. ......... .... 10 0624 6 i 20M J Al A h 21" 7.7 13.2 2.4 1.9 2OU J` ............. 0 I_ �2 A .... " "' ".Al ..... . ........... 1: A 10 01:10 ........ ..... 1 ...... ................. ... 1 1,43 - ....... . ....... . . ....... 72 11 129A ....... .......... ?1�§ 0825 2., . .... .... 20M Al 7i .... ....... .... . ...... ..... ... �111J_ _13 11? Ipj 6116 ... qpj?p��.,..4 .......... Ai ........ 2.2 6.7 9.8 ........ . ...... . �d ......... . ............. . ..... ...... 3.4 1.9 ..... .... ..... .......... ... ....... 1 .......... 1 ... 11.1 ... 13 "2 0 �?PM "'91:10 91�?q J J6 6 t Tg' 9-.6 12.3 0825 5' 20M' D Al A 3.8 ".". q 8.4' . ........ 1 13.6 ....... ..... ....... ..... 11 11.1.11_ 11,19& _IM JA-.�__ 0825 6 .......... OM .......... .......... I 1191109�111111 10 .. .." ...... 3. .......... ... ........ . .......... 20M - I AC D ...... . ..... 10 ... .. .. 01 ........... .. I ... ..... .... 0825 8 ..... . . ......... AC 1 ........... D . ... .... ............ Al �.�; ;� I % .......... ... . 01:20 .......... 0.7 1.7 3.3 1.0 1 6. ..... . 2.6 2.6 2.7 0825 9 ..... ..... ... 20M ... .... ... Ai A .......... 19 ... ... 1.8 .. f ........... . .............. ........... ..... 2.2 082510 .... . ..... ....... 7111.1111.�_, 20M ..... ... ...... .. ..... ........... ......... . .... ... . i'O 46: 34 „A1 .......... . .... . -3.0 0.5 ......... ON& Al B 1 Al 9�9; i 1,43 i _j ......... . 0826 2 - 20V, ..... . . ....... ................ 7.2, 11.9 41,6 134, 0826 3 g0l Al B Al hi .8' .0 3.9��;,.�� ;. 826 ......... . ..... ....... ...... .. . ..... .... .. ....... 10, 23 . 6826 6 ........ 20h Al ........ ... M A' 10 OMU 5.9:: A lz.91111_1 1,9 .2 10;9 1 14.0 12 .9 ............ M". Al k: .............. ....... .......... . .. . .. . .. . . .............. 19 a 68; . . ..... ..... ..... - 66 ... ... . . •............ ....... I . ..... (SM AC . ... .......... ... D Al ............ A 10 qq;Aq� I 31 211.6 . ...... 6826t 8 q: 6 1_ i _1191... 2.9: 111.111.11 .......... 2.4, .......... 7.9 --1 I ........... ...................... 13;.1 1 ... 616 .... ...... .......... 1 ..... ...... Al .......... .......... 1 91, 20 4.6 ... j _16�8 �. 93 6- .. 0830 2 I ........ 1 . 201V ........ ... ....... ... .......... M 1� 12.9 7.0 .......... N.&: ;."J" 083D 3 A $1 . I • 1 0138, Tj 128 200 44 t A-§ ............ ..... . ... "2Om ............ A ....... ... 10 ..... ... .:,....71 1. 7 2.6 1.0 .......... 0:7 23 0830 5 . . ....... . .......... 20M- . j t L j,R ... 0155„ .. ...... -;;, 31 ... ..... .... ................. ... .9 ... ... 11 5d 66 -65 C ? �6 10 0202 .. ............ 3 .... .... ......... ...... 14 6.2 . .......... 6830 7 20W • 1 Bi ........... ! A ............ 0227 ... ... II.I...!? . ..... ...... 13.5. 10.5 12.5 • _j .. .......... AC . ......... .. ........... .. ...... .... ..... . .......... . ........... ........ ... . ......... ... ...... .... .... 0.1 OA ........... . 1 02� 02 0.2 08309 .......... € 20M Al ..... . t D .. ...... ........... BI ....... ... 01:18 3.9 .......... 5,6 7.2 14.1 • i&g D830 10 .... ......... ...... ...... . 20M. Al i .... . L T ............ 19 1 Al._J 6.7 �j • 14.0 0830 115•" . ....... ..... .... _ 20M: Al -P .......... . .... 131 . ..... i 0 2.6 I_IP.i? 6.8 6630 12 20M A6 D 131 10 1 00:55 0.5 0.4 ......... . ..... ... 0.4 ....... 0.3 ........ ... _j.;9 ........... .......... 0.3 ... ............ ... . t ........... ........... .... .............. ............ •A . ..... ........... A ......... j . ... ........... ..... ....... 02:33 1.3 .. ........ 2.3 . ...... 11.0 ................. 1 .2 1 15.7 0831 2 20M :, .. . ........... ......... A 10 03:31 1.9 6. 9.5 3.2 .... 2.2 ...... ...... 1 i I . �Z,? .2 J T I ....... .... ........... ... 19 03: 5 2.3 ....... . . M. .......... 20.0 : _6 A 10 1—— 02:51 .111.. :16..1...." 6 1.8 2.5 -1 _[. 0.6 i 0.4 ......... 2.1 . . •......... .. ............ 2.1 ....... .... ........ . .. ... .... . ......... ............. ...... . ...... .. B i 4 . ..... i A t ... , f ff" . ...... ............. 03:14 .. ................ 01 ........... ..... .. 03 . ... .......... .. 06 . . ....... ......... 0.1 .......... . ..... F, ..... 1 ft! ....... ......... . ...... .......... J ........ 1111111 ... 90 1 2 •SON pa W1111 RO f A&: I_ _92. 4 0831 7 20M Al .......... ... .... ... F ......... . ...... 131 ........ i A ... 1 . ....... 0357 .... .... .. 02 0, Z 08 OAr 0.1- 7 ........ . . . .......... 9!.A. 06 ....... 10 6Y:66 6 R!.9 .......... ........... 9A 0631 9 20M At 8: ............ B1 A ............. ................... 79 i 0831: -10 -20M Al B i 131 J i .... ..... ...... ... ....... I ..... 26 t 9:2 i_....8.6 . ........ i 9.2 . AC I -T ........... . ...... JA 9A.a P_ 1.8 ..... . ......... 121 .......... ..... .... _ ..... ... ....... 5A -M 2.9 -.S 25 8 ....... ... ....... .. ..... .... . . . PNIJA4 . • ...20N .................... . M hl .................... : �!: . 6 ... .... . .. ; . 91n . . .. .... . . ........ ..... 22 �� ..... ..... 0831.14 ...... I :8� .6 _�........ A .. Ol .1 .... ...... . . ........ ... . . ... 01 17 28 1 12�1.11Aiq .. . . . ............. IA_ T, qi§ .- . .-.,,. ,,,20M 0107 . .. . .. 1 3 2.6 2.4 20M A5 PA A ... 9,-k .... ...... - .......... . ,qqj 083117 20M!`-T7AI . ...... . A ........ .. i Bi A . ........... 10' 01: 6.3� 7:8 1� 10;0' ...... 2.3 1.5 6.01 6.1 6.1: Table 13 (part I of 2). Emission test airborne particulate matter concentrations. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT 1 Page 52 of 63 Revision: 2 January 27, 2006 Clean I Area I Time I PM 2:5 I PM10 I TSP I PM 2.5 I PM 2.5 I PM10 I PM10 I TSP ................... C ................... ................ — B 1 1 10M 10 meter long chamber A Asphalt * ** Distance A= 2 meters, Distance B = 6 meters 1 CE -CERT 20M 20 meter long chamber 2 Kearny Site 1 * ** Distance A= 6 meters, Distance 8 = 16 meters 3 Kearny Site 2 Material B CementISidewalk/Driveway A 120.g Surrogate Dirt < 425 micron, 60 g grass, and 60 g leaves 1 CE -CERT 1 Surrogate: Kearny 2 Kearny Site 1 2 Surrogate: Other - 3 Kearny Site 2 3 Surrogate: Five Points 4 Kearny Site 3 4 Surrogate: Fresno C Lawn 5 Surrogate: Shatter 1 CE -CERT Site 1 6 Surrogate: Madera 2 CE -CERT Site 2 C Control 3 CE -CERT Site 3 B 60 g Surrogate Dirt < 425 micron, 60 g grass, and 60g leaves 4 Kearny Site 1 1 Surrogate: Kearny 5 Kearny Site 2 2 Surrogate: McKItrIck 6 Kearny Site 3 3 Surrogate: Five Points D Gutter 4 Surrogate: Fresno 1 CE -CERT Site 1 5 Surrogate: Shafler - - 2 CE -CERT Site 2 . C Control - - 3 CE -CERT Site 3 C Soil /Dirt/Graas cuttings, etc., as is at the time time chamber was set up 4 Kearny Site 1 1 Control 5 Kearny Site 2 Blower E Packed Dirt Parkin Lot A _ Electric Blower In blow mode Cleaning Pattern B Electric Blower In vacuum mode A In 20 meter chamber: 5 m^2 to 15 m"2, 1 meter wide 1 Vaccum full In 10 meter chamber: 2.5 m^2 to 7,5 m^2, 1 meter wide C Gas hand held blower B Full 2 meter width from 1 meter into chamber D Gas Backpack Blower C Gutter onto grass E Push Broom D Gutter F Rake E Sidewalk onto grass Table 13 (part 2 of 2). Emission test airborne particulate matter concentrations. ` As discussed by in Section 3.2, the average between the concentrations determined at the l Om and 16m sampling locations are being used to calculate the emission factors. The emission Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT factors are calculated using the following equation: EF = [((C 10 aw,t =6 + C 16 ave,t =6)/2) x Vchamher] / Adebris Page 53 of 63 Revision: 2 January 27, 2006 (1) Where EF (mass /unit area) is. the emission factor, C10 and C16 are the concentrations (mass per volume) determined at those respective distances, V is the volume of the chamber and A is the area that the surrogate debris was spread over. Equation 1 and the data from Table 13 were used to obtain the emission factors shown in the following tables. Table 14 presents the average emission factors for test runs conducted to look at the differences between soil types used in the surrogate matrix. There were no significant differences between the soils tested. Basis: 10m ^2 cleaned in an 80m ^3 chamber All emissions are from cleaning with an electric leaf blower Table 14. Leaf blowing emission factors for various soils tested. The emission factor data obtained for testing using surrogate soil (from Kearney) on an asphalt surface are presented in Table 15. The emission factor data obtained for testing using surrogate soil (from Kearney) on a concrete surface are presented in Table 16. The l Om chamber was used for twenty -three test runs over natural /indigenous surfaces. Nine of these runs were performed at the UCR CE -CERT facility and twenty- three were performed at the UC Kearney facility. Table 17 lists these thirty -two test runs, the surface type of surface cleaned, the cleaning tool and the area cleaned. PM 2.5 PM10 TSP Soil Source Surface Cleaned (mg/m`12) mg /m ^2) (mgfm ^2) Shafter Asphalts 10 40 ...., . ,.,,., ........ 50 ................ .... ..... . : Five Points Asphalt 10 40 40 Five Points Concrete 20 60 50 :.:.::................:::.::... Shafter :..:::.::..............:...:.::::...............:..::.:::.....:..........:.:::::................::::::...................:::::::...........:....::::.:.............:....::::::.:.............. Concrete 10 .:..:,...................:,...: _....,.........:.....................,..,,,,....................:............... 30 40 ......... ....::...:........ .... ............ .......................:....,.. _............:....................................,,............:...................,.,........,..,........ Kearney Concrete 20 50 60 Fresno Asphalt 10 40 40 Madera Asphalt 10 1 . 60 70 Averaae 10 50 50 Basis: 10m ^2 cleaned in an 80m ^3 chamber All emissions are from cleaning with an electric leaf blower Table 14. Leaf blowing emission factors for various soils tested. The emission factor data obtained for testing using surrogate soil (from Kearney) on an asphalt surface are presented in Table 15. The emission factor data obtained for testing using surrogate soil (from Kearney) on a concrete surface are presented in Table 16. The l Om chamber was used for twenty -three test runs over natural /indigenous surfaces. Nine of these runs were performed at the UCR CE -CERT facility and twenty- three were performed at the UC Kearney facility. Table 17 lists these thirty -two test runs, the surface type of surface cleaned, the cleaning tool and the area cleaned. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 54 of 63 Revision: 2 January 27, 2006 'fable 15. Emission factors for blowing, vacuuming, ralung and sweeping on asphalt surfaces. CE -CERT with surrogate soil Table 16. Emission factors for blowing, vacuuming, raking and sweeping on concrete surfaces. Draft Final Report Page 55 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 Surface Cleaned Area Cleaned: Cleanin Tool (MA Cleaning Time sec /mA2 PM 2.5 PM10 m /m ^2 m /mA2 TSP ` (Mg/MA 2 Lawn - CE CERT +; Elec, Leaf Blower _ .................... ...............,,........... .........,..................... As halt Driveway - CE -CERT P ......,::,......,.,..,....,: ,....:...,..,...._....,....... Elec, Leaf Blower ! ..8 ..................[._............:,. 10 ......6......................., 10 .......... ,0,2....,...._<.,..._.......... 4 ,,. .....1............0c5.,........ 14 15 AsphaltDriveway -0E,CERT control Elec, Leaf Blower 10 8 .. 2 6 5 „ AsphaltDnVeway CE CERT .,. Elea Leaf Blower ; 16 13 3 10 10 .. ..... Asphalt Driveway„ CE CERT control Elec. Lea. Bower ... 10 6„ „1 4 4 r ...............,..., .. Lawn CE CERT 5...._ Elea' LeafBlower:...' 8.................. 1...,................._ 4.....:......,.................... 0, 2..... !_... �c5...... ............... ................. ............ ...... .................. Lawn - CE -CERT - control :................... ? Elec. Leaf Blower 18 4 .......!_:_.0:3.. 0 2 ......... 0.5 . .. ... ........ 0.6 ..0.6 ......... ........::.............:..:...::::...........:..:.....::.............:::.:.::..:.................:...................:..:.:...._......,,..,::::,,...........,. Gutter - CE- CERT.. a.„,:,,,.:........:.:,.,::::.............,:,,,:,,,,,......:..... .....,................_:,,,...' L....Eleo Leaf Blowef....! ...., ,,.. ...... ........„ 2 5 ., 7 .......... Gutter CE -CERT - control ..... .......... Elec LeafBlower .......... ......,....._.. 5 4 ......�.�..,_......:......._... 9 ... 3 " 12 Grass on Concrete Walkway „Kearney +„ Elec Leaf Blower ' "' 9 ",.', . 5 2 9 16 „ , ,,,,,,,,,,,,, Grass on Concrete Walkway - Kearney control Elec; Leaf Blower ': 9 ” 5 1 4 6 „ on Concrete Walkway- Kearney 11.1 ; Elec Leaf Blower 9 i 6 0 1 2 „Grass Grass on Concrete:Walkway Kearney Elec Leaf Blower 9 . 5' 0 ... ....... 4 ._control Gutter- Kearney Elec Leaf Blower 9 6 18 50 106 Gutter Keamey Control „ .... LeafBlower , 9 " "5 ., 23 49 .. "' .....:,,,,, Gutter Kearney „Elec Elec Leaf, 9 6 7 21 25 ........ .... ....................... .......... Gu(ter- Kearney Control .. I Elec Leaf Blower '€ ....., ..'. 9.. ; ,.,.... ,,, ........... 4 2' ....... ... „,.. 6 9 J. Lawn - Kearney, i Elec. Leaf Blower 18 2 0.1 2 0 3 Lawn - Kearney - .control I Elec. Leaf Blower i 18 3 0.1 ”„ 0.2 "„ 0.3 '. .. AsphaltprlvewaX- .Kearney Leaf-Blower 18 ,3 3 11 20 .... Asphalt Driveway Kearney control Elec Leaf Blower 18 2 1 , 5 9 As haltgDriveway Kearney Elec. Leaf Blower 1 39 67 93 Lawn - Kearney Elec. Leaf Blower „18 18 1 2 5 9 Packed Dlrt Parkin�,Lot Kearneyy Elec. Leaf Blower ( 18 „ 2 .............. ..... 76 118 162 PackQ Dirt Parking, Lot Kearney control Elec. Leaf Blower 18 3 92 141 220 Gutter Kearney .. Rake 9 "' 10 ” 0 4 2,2 3.2 Gutter - Kearney Rake 9 ,, ...,,,. , .._,,,.. 10 "' 1 3 4 .....�.,,,.. Lawn Kearney ,.,,,,, Rake 18 8' 0 1 1 Grass on Concrete Sidewalk - Kearney , Push Broom 9 10.3 Grass on Concrete Sidewalk Kearney control Push Broom .... 9 0 2 5 6 ....... <.,. Asphalt Driveway Kearney Push Broom 18 12 11 35 - 39 Asphalt Drivewa Kearney control Push Broom 18 8 13 37.....f 38 Aversa all; except, controls) ....... 1 ......: ........................,....., . ,.... ............................... ............................ ............................... € .................. ............................... . ...$.........................19 ............ .. .. 28.... Average (power blowers only, not including controls) ...............::,,:,,..........,,,,..:::,:,.............,.,::::::,.............,..,.,,,::,................:::..::,.......... ,::,..:,:.::,................., :::,..........,.....:::.::... 5 ........ ...,::.:::::.,..........,...:,..... 11 ............,. 22 <::: ........ _........ ..... 33.... ..... _ ....:::.:::..:.:............::::.:........ .......:..:::.:....:..........- Average..of..power.blowing lawns........ ................. ................... ..:.............. ................... ................... ; .................. ........ ...... .. Avers a of ower blowing utters 9 :............. P.,......,..,.,........,,,.........,,,......,.......,.,.,........,,., ....._,...,.......,,........... ,.......,..,.......,,,.,,......,,.,,.......,,,,,.......,,,,.....,...,.........,,,.......,.,........, ,.,.:....,,.........,,.,,.....„ . ..,. 9 ,,,... ..._......., ..._i 26 ..... ............. ...... 46 46 .... Avers a of ower blowing cut rass on walkway 2 6 9 Table 17. Emission factors for leaf blowing natural /indigenous surfaces. 4.6 Data Accuracy, Precision and Completeness The results from the collocated DustTrak data from all of the test runs with valid data are presented in Table 18. The precisiorris within the variability of the individual tests. Standard Number of Average Deviation of Particle Cut Size Data Pairs! Difference (percent) ? (percent) PM -1-0 93 -14 27 .......:.::::::::....._...,:,,.,::: ::,.......:.....::::::::,..,.., :, ..... 85 -7 19 Table 18. Collocated DustTrak data. A performance audit of the flow rates for the six filter samplers was performed. The auditor found all samplers flow rates to be within the project goal of + / -10 %. The audit report is included as Appendix B of this report. Draft Final Report Page 56 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 The study had a very high level of data completeness. Out of the 56 filter samples attempted 48 viable samples were collected. The lost eight samples were due to tearing of the filter media in the sample holders. The project required six DustTraks. We were able to obtain two additional DustTraks. These additional DustTraks were collocated with selected primary DustTraks to provide quality control precision data. They were also ready to be used as backups should there by a failure in a primary sampler. All eight DustTraks were operational for all but the last study day. We had one DustTrak fail about half way through the final study day. One of the backup collocated DustTraks was used in place of the failed DustTrak for these final runs. 5.0 EMISSION FACTORS The emission factors obtained have been reviewed to better understand these numbers. As shown in Table 17, the values for TSP obtained from leaf blowing lawns were 0.5, 0.5, 0.3 and -9 Mg/M3. The reason for this large range can be seen in the following figure: Figure 34. Photographs showing lawns with lush and lean foliage. The photograph on the left is from the lush foliage lawn from one test location that had low PM emissions from leaf blowing. The photograph on the right in Figure 34 is from a lawn with bare spots used for the test that had the high PM emissions from leaf blowing.'Since both lawns and representative of those in the SJV, the range of emission factors from blowing lawns will also vary accordingly. We observed a significant variation in emissions from asphalt. As shown in Table 17, blowing asphalt driveways at the UC Kearney resulted in emission for TSP of 20 and 93 µg /m3. Although a variation of a factor of five is not unusual, this variation was observed by simply moving the chamber 2m to the side from the first test location to obtain the second test location. One possible explanation for this was that the asphalt driveway was slightly curved or sloped to better enable water run off and our second (higher emission numbers) sampling location was at a low Draft Final Report Page 57 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 spot where water drained, carrying sediments. As shown Tables 1.5 and 16, there was a range of emission factors obtained from the different leaf blowers and leaf vacuums as well as from raking and sweeping. Due to the variability of emissions from one test to the next, there were no significant differences between the power leaf blowing and vacuuming methods that were clearly identifiable above the measurement uncertainty. As an example, the three test runs for leaf vacuuming off of asphalt surfaces (Table 15) had the highest emission factors for asphalt surfaces, but the three test runs for the leaf vacuuming off of concrete surfaces (Table 15) provided emission factors that were in the middle of the emission factor range for concrete surfaces. To best represent the range or real - world conditions in the composite emission factor, we averaged the concrete surface emission factor data from power leaf blowing and vacuuming operations into a single emission factor, and did the same for the asphalt surface blowing /vacuum emission factors. These emission factors, along with emission factors from raking lawns and power blowing gutters, packed dirt, and cut grass on walkways are compiled in Table 19. Cleaning Action and Surface Cleaned i Number of Testai Performed Type of Emission Factor Obtained froml Tests Emission Factors PM 2.5 : PM10 I TSP m /mA2 mg /m^2 ' (mg /m ^2) Power Blowing or Vacuuming over concrete surfaces 12 Average emfssionsfrom lea............... f blowing 30 80 100 Power Blowing or Vacuuming over asphalt surfaoes 21 Average emissions from leaf blowing 20 60 80 Push Broom on Asphalt Surface -3 Average emissions from sweeping 0 20- 30 A" Push Broom on Concrete Surface 3 Average emissions from sweeping 2D 80` 110 Raking on Asphalt Surface : 1 .- ..,.:... ..,..,.,. ..,.,, w Average emissions from raking 0 0 - 0 Raking on Conc§tbi Surface 3 Average emissions from Yaking 0 Raking Lawn Average emissions from raking 0 1 1, Power Blowing Cawn 3 Average emissions from leaf blowing 1: 2, 8 Power Blowing Gutters 3 Average ;emissions -from leaf blowing 9 30 50 Power Blowing Packed Dirt 1 Average emissions from leaf'blowing 80 120 160' . .. ....Power Blowing Cut Grass on Walkway 1. .,2 Average emissionsfrom leaf blowing 2 3 6 ' 9. Table 19. Summary of emission factors. The highest emission factors .were from power blowing packed dirf'surfaces. The packed dirt surfaces had both the same fine particulate matter deposited on its surface that the asphalt and concrete surfaces had, plus it was composed of a dirt surface that could be disrupted and entrained in the air due to the leaf blowing. The second' highest TSP' emission value and one of the highest PMIO and PM2,5 emission values was from broom sweeping on a concrete surface. As can be seen in the table, the emission factors for broom sweeping on an asphalt surface are among the lower PM emitters. The broom operator was able to move the surrogate material along the concrete surface quite rapidly with the broom; resulting in emissions similar to those obtained with power leaf blowers. When sweeping the porous asphalt surface, the operator swept at a similar rate, but the bristles of the broom did not thoroughly penetrate the porous surface. We presume that a significant portion of the dirt material that was laid out was pushed into the voids in the porous asphalt surface. This deposited mass was no longer being pushed along and potentially entrained in the air. Draft Final Report Page 58 of 63 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT January 27, 2006 For all surfaces and operations, raking resulted in the lowest emissions. The TSP and PMIO emission factors were similar in magnitude. The PM2.5 emission factors were between one fifth and two thirds the emission rate of PMIO. 6.0 EMISSI ®N INVENTORY The emission inventory was developed using the emission factors and activity information based. on the number of residential units cleaned, the area cleaned and the frequency of cleaning. The emissions at commercial facilities were estimated to be one third of the residential emissions. Data on the area typically cleaned and the time spent at each task was gathered from interviews with operators and observation of operators at work. Several residences, single family and multiple unit, and commercial locations were visited to estimate areas requiring cleaning. From this data, the area cleaned and the time spent per task were determined for each unit of typical residence and commercial location. Tasks that were observed included cleaning of planter areas (similar to "packed dirt "), lawn surfaces and asphalt and concrete driveways and sidewalks. The area cleaned was determined to be approximately constant from spring through fall, with a 50% reduction of activity in winter. Tables 20 and 21 show areas cleaned for non- winter and winter months respectively (winter is defined as January- March). Table 20. area cleaned per week, non- winter months. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Table 21. Area cleaned per weep, winter months. Page 59 of 63 Revision: 2 January 27, 2006 For each season, s, the following calculation determined a seasonal emission factor for each housing type, h. For each housing type, the typical area cleaned for each task was multiplied by the emission factor for that task, t. The number of units of each housing type was determined from field H30, number of units in structure, from the 2000 US Census. The resulting emissions for each task were summed over all tasks to produce an overall emission factor for each housing type. This calculation was repeated for each season. Alas x EFt = EFnt, I EFI t, = EFhs We estimated that leaf blowers are used at a frequency of once per week for all residential applications. For single- family residences, we estimated that one -half of the residences use leaf blowers in some capacity to aid cleaning of the yard, either self- maintained or professionally maintained. For multiple-unit. housing we assumed that professional perform yard maintenance on a weekly basis. Table 22 summarizes the key emission factors used for the emission inventory calculations. These factors' are from the data shown previously in Table 19. Specifically, the four entries used are blowing /vacuuming on concrete and asphalt, power blowing, lawn, and power blowing packed dirt (for planters). Using Tables 20 -22, the stated assumptions, and the equations above, we calculated the emission .rates for all residential classifications by multiplying the emission factor by the area estimated for each of the four tasks and summing the four tasks. Tables 23 shows the results for non - winter months and Table 24 shows the results for winter months. Area m /unit Housing Ty pe Planter Lawn Asphalt Concrete 1 unit, detached 11:0 138.9 10.0 11.0 1 unit, attached ...... ...............:............. 11.0 ; ............................... 138.9 _....,....................,..........:,;............ 10.0 ;:::::::,. ..........:.................... 11.0 » ...........:.»::::,:,,... .........:,.:::::::,:........,» 2 units 7.0 .::.........,»,,::,::::.............»»:::»: 69.4 ................ 5.5 ..:......., »,,., »:........,.... 7.0 3 or 4 units 5.0 46.3 5.0 , ............ 5.0 5 to 9 units 2.9 19.8 ! 2.5 ! 2.9 10 to 19 units 2.1 9.9 1.4 2.1 20 to 49 units .....,...... 1.3 ...,:... m ........... ..:...........................a 4.6 8..:...........;.... ....:........1..,3.,........... 50 or more units 0.7 ..............._....,..................,...,...................... I ..........,......,.:........... 0.4 ,... 0.7 Mobile home 2.5 2.5 2.5 _:,,..................»»:................ 2.5 _ .....:.::.:.:..............:::::»..::....._...,:.:»::..............,,,::::::..............».:..::,.............».::::;..,..... Boat, RV, van, etc. 0.0 ........,.:::.:.,:........... 0.0 »„ :»,,,,,.. 0.0 ........_.... »,.,.,............ 0.0 Table 21. Area cleaned per weep, winter months. Page 59 of 63 Revision: 2 January 27, 2006 For each season, s, the following calculation determined a seasonal emission factor for each housing type, h. For each housing type, the typical area cleaned for each task was multiplied by the emission factor for that task, t. The number of units of each housing type was determined from field H30, number of units in structure, from the 2000 US Census. The resulting emissions for each task were summed over all tasks to produce an overall emission factor for each housing type. This calculation was repeated for each season. Alas x EFt = EFnt, I EFI t, = EFhs We estimated that leaf blowers are used at a frequency of once per week for all residential applications. For single- family residences, we estimated that one -half of the residences use leaf blowers in some capacity to aid cleaning of the yard, either self- maintained or professionally maintained. For multiple-unit. housing we assumed that professional perform yard maintenance on a weekly basis. Table 22 summarizes the key emission factors used for the emission inventory calculations. These factors' are from the data shown previously in Table 19. Specifically, the four entries used are blowing /vacuuming on concrete and asphalt, power blowing, lawn, and power blowing packed dirt (for planters). Using Tables 20 -22, the stated assumptions, and the equations above, we calculated the emission .rates for all residential classifications by multiplying the emission factor by the area estimated for each of the four tasks and summing the four tasks. Tables 23 shows the results for non - winter months and Table 24 shows the results for winter months. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Emission Factors ................ ......:.:, ...........,,:::,...._ ........ ........... .w..... <:, Planter Lawn Asphalt Concrete PM 2.5 80.0 1.0 20 30 » .:..:..............::::: ..................::..:.......0 2......... . »:::::,,;...................2' .. .0 .............. .....,.................,,, PM 10 12 60 80 0 .::::............»::,:::,, ...,.......,,,. »::: »,..,......: »»,::::::,.. .........:.. »::::::............ ;, .,:::: »,.......,......... ............. ........ TSP 160.0 3.0 .80::: 1. Table 22. Emission factors by task. Table 23. Emissions by housing type, non-winter months. 'fable 24. Emissions by housing type, winter months. Page 60 of 63 Revision: 2 January 27, 2006 Finally, seasonal emissions are determined for each county by multiplying the number of units of each housing type, by the emissions by housing type, for that season, to arrive at the emissions for that county for that season. Ul,. x EFhs = Eh, , ZEhso = Esc Emissions from commercial locations were assumed to be one third of the total emissions from residential locations. Overall total emissions were obtained by summing the residential and Draft Final' Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 61 of 63 Revision: 2 January 27, 2006 commercial emissions. The number of units of each housing type, shown on Table 25, was determined from field H30, number of units in structure, from the 2000 US Census. The emissions by county are shown on Tables 26 and 27 for winter and non - winter months respectively. Only those portions of Kern County within the District boundaries were included. Table 28 presents the leaf blower emissions on an annual basis in tons /day. Fresno ' Kern >' Kin s Madera` Merced 'San -Joa uin :':. Stanislaus. = Tulare ..... otal: 270,767' 183,041- 36,563`' 40,387 68,3731 189,160 unit, detached 175,3801'126,792125393 , 30,854 48,011: 129,289 unit, attached 10,068 6,889 2,144 1,3411 2,534"i" 534' 11,223 units 6,766 5,456 1093 499 1,8291 4,975 or 4 units 17,3881 10,770 1,6291 1,6191 3,339: 8,374 to 9 units 13,598, 5,694' 1,232. 1,012' 2,744: 6,233 ..............»»,:::::..,...:...,»»,::::::.,.... 0 to 19 units ..............:.,,.,:...... » ».: »:::,..,,....._.,, ,.:::....,........, » »,::::::,., .......,, 7,352; 3,2551 870 , » 3651 „ »...::.:, 1,4091; »......... 4;863 0 to 49 units 8,0491 3,8711 748; 452; 1,137; 4 546 ..............,................ ................................................................. 0 more units ............................... ............................„...:...,...........,,............,.........,......._...:.........,.»......................,,........,...,................,....... 18,8101 7,693; 1,376; 882; 2,1361 10,468 „or 9obile home 12,737: 12,2261: 2,0521 3,068; 5,079: 8,736 goat, RV, van, etc. 619E 3951 261 2951 .... .........................._.... 155:1 453 Source: U.S. Census Bureau Census 2.000 H30. UNITS IN STRUCTURE [11] - Universe: Housing units Data Set: Census 2000 Summary File 3 (SF 3) - Sample Data Table 25. Number of units by housing type. 7 M 1 950 1,782 1%0,431 309 Table 26. Leaf blower emissions by county, non- winter months. Table 27. Leaf blower emissions by county, winter months. Fresno 1 Kern =: Kings Madera Merced `S Joaquin Stanislaus ` Tulare PM 2,5 Ib /da Y)............_................. 74 I 52 11 12 20 54 44 35 _ . ............4.................. PM 10 Ib /da ................:.._........... 147 104 21 23 39 ...... ... 106 87 70 TSP (lb/day) 195 ? 137 28 31 51 .......... 141 115 92 Table 27. Leaf blower emissions by county, winter months. Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 62 of 63 Revision: 2 January 27, 2006 Kern (SJVAPCD Fresno: portion) -Kings; Madera 1 Merced S.Joaquin Stanislaus :Tulare.- iota) ......_..... ...._... ......... ..... .................. ..:......................................._....................................:...... ..... ..............................................._...........................,,.....,............................. PM 2.5 (tons /da) 0.07 0.05 0.01 Y 0.01 1 0.02 ...... ...... 4....... 0,05 ............. ...... ................;._.....,...._........... :........... 0.04 '. 0.03 ........ ........... 0.26 ,.............................. ............._......................,..,...................................................,......... �....,.........................,.......................:.........................,........._.....;................,_.......,............:............_............... PM 10 (tons /day 0.13 0.09 0.02: a 0.02 0.03 0.09 0.08 0.06: 0.52 ..._. , ................ _.................................,..:.................................. TSP (tons /day) 0.17 0.12 0.02 ............................... 0.03 0.04 M.... _..............., 0.12 ....... ...........................:. 0.10 0.08 ............................... 0.69 Table 28. Annual emissions in the San Joaquin Valley from leaf blowing activities. The results shown in Table 28 meet the project objective and are based on the application of emission factors determined by operating leaf blowers in an enclosure to estimated activity in the San Joaquin Valley. While there are many potential sources of uncertainty, like all emission inventories, these results represent a major improvement for this emission source. 7.0 REFERENCES Botsford, C.W., Lisoski, D., Blaclanan, W., Kam, W. (1996) Fugitive Dust Study - Characterization of Uninventoried Sources. Final report AV- 94- 06 -214A AeroVironment Inc. Monrovia, CA. March. California Air Resources Board (2000) A report to the California legislature on the potential health and environmental impacts of leaf blowers. February. Chow, J.C.; Watson, J.G.; Lowenthal, D.H.; Solomon, P.A.; Magliano, K.; Ziman, S.; and Richards, L.W. (1992) PMIo Source Apportionment in California's San Joaquin Valley. Atinos. 1'nviron., 26A: 3335 -3354. Fitz, D. R. and K. Bumiller (2000) Determination of PMIo emission rates from street sweepers. J. Air Waste Manage. Assoc. 50: 181 -187. Fitz, D. R. (2005) Quality Assurance Work Plan for Measurement of Particulate Matter Emission Factors and Inventories from Leaf Blowers. Unnumbered UCR report. August 9. Revision 1. Pope, C.A., Thun, M.J. Namboodiri, M.M., Dockery, D.W., Evans, J.S., Speizer, F.E., and Heath, C.W. (199 5) Particulate air pollution as a predictor of mortality in a prospective study of U.S. adults, Ain J..Respir°. Crit. Care Med, 151: 669 -674. Venkatram, A. and D. R. Fitz. (1998) Modeling of PM10 and PM2.5 emissions from paved roads in California. Final report prepared for the California Air Resources Board contract 94- 336. March. Chow, J.C.; Watson, J.G.; Egami, R.T.; Frazier, C.A.; Zhigiang, L.; Goodrich, A.; and Bird, A. (1990) Evaluation of Regenerative -air Street Sweeping on Geological Contributions to PMI0. J. Air & Waste Manage. Assoc. 40, 1134 -1142. Lowes (2005) Leaf Blower Buying Guide. www.lowes.com /lowes /lkn? action= howTo& p= BuyGuide /leafblower.html &rn =Ri hg tNav Files /right.. Compilation of Air Pollutant Emission Factors, AP -42, Volume 1: Stationary Point and Area Sources, Fifth Edition, U.S.E.P.A.., Research Triangle Park, NC, January 1995. Standard Test Methods for Particle -Size Analysis of Soils., ASTM Method 422 -90. American Draft Final Report PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 63 of 63 Revision: 2 January 27, 2006 Society for Testing and Materials. Philadelphia, PA, 1990. Home Depot (2005) Blowers and Accessories. www, homedepot .com /prel80 /HDUS /EN_US /j search /searchResults. j sp ?com.broadvision.session. new =Yes. Consumer Reports (2003) Power Blowers. Consumer Reports Magazine, Pg 44 -46. September. APPENDIX A: Quality Integrated Work Plan QUALITY INTEGRATED WORD PLAN FOR Factors and Emission Inventory from Deaf Blowers in use in the San Joaquin Valley Revision: 2 November 1-8-,2005 Prepared for: San Joaquin Valley Unified Air Pollution Control District 1990 Gettysburg Avenue Fresno, CA 93726 Principal Investigator: Mr. Dennis R. Fitz College of Engineering Center for Environmental Research and Technology University of California, Riverside Riverside, CA 92507 Quality Integrated Work Plan Approval and Distribution Title: Measurements of Particulate Matter Emission Factors and Inventories from Leaf Blowers, Revision 2, November 18, 2005 Signatures indicate that this Quality Integrated Work Plan (QIWP) is approved and will be fully implemented in performing the research project described in this document. Dennis Fitz Principal Investigator Signature Date CE -CERT University of California, Riverside David Gemmill Quality. Assurance Officer Signature Date CE -CERT University of California at Riverside Gary Arcemont Air Quality Specialist Signature San Joaquin Unified Valley Air Pollution Control District Date Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers Revision; 2 University of California, Riverside CE -CERT November 18, 2005 TABLE OF CONTENTS 1.0 INTRO.DUCTION ..................................................................................... ............................... 3 1.1 Introduction .................................................................................... ............................... 3 1.2 Background .................................................................................... ............................... 3 1.3 Project Objectives .......................................................................... ............................... 4 2.0 PROJECT MANAGEMENT ..................................................................... ............................... 4 2.1 Project Organization ...................................................................... ............................... 4 2.2 Personnel Qualifications and Training .......................................... ............................... 6 2.3 Communications Plan .................................................................... ............................... 7 2.4 Project Schedule .............................................................:.............. ............................... 7 3.0 PROJECT ASSESSMENT, DATA QUALITY OBJECTIVES, CONTROLS AND CORRECTIVEACTION .......................................................:........................ ............................... 8 3.1 Project Assessments ....................................................................... ............................... 8 3.2 Data Quality Indicators .................................................................. ..I............................ 8 3.3 Routine Controls and Procedures ................................................ ............................... 12 4.0 MEASUREMENT EQUIPMENT AND METHODS ............................. ............................... 13 4.1 Real -Time PM Monitors - DustTraks .......................................... ............................... 13 4.2 Time- Integrated PM Measurements using Filter Samplers ......... ............................... 13 4.3 Wind and Air Flow Rate Measurements ...................................... ............................... 13 4.4 Propylene Tracer Gas Measurements .......................................... ............................... 14 4.5 Data Acquisition System ............................................................. ...................:........... 14 4.6 Leaf Blowers ................................................................................. ....:.......................... 14 4.7 Rakes and Brooms ....................................................................... ............................... 15 4.8 Test Chamber ................................................................................ ............................... 15 4.9 Safety Instruments ....................................................................... ............................... 16 4.10 Soil Silt Content .....................................................................:... ............................... 16 4.11 Fertilizer Spreader ...................................................................... ............................... 17 4.12 Triple Beam Balance .............. : ...... ............................................................................ 17 5.0 MEASUREMENT PROGRAM .............................................................. ............................... 18 5.1 Design and Evaluation of Test Chamber ..................................... ............................... 18 5.1.1 Viability of Structure ..................................................... ............................... 18 5.1.2 Determination of Amount of Material to be used ......... ............................... 19 5.1.3 Dust Plume Characterization ........................................ ............................... 19 5.1.4 Mass Balance ................................................................ ............................... 20 5.2 Real -Time PM Sampler Collocated Testing ................................ ............................... 20 5.3 Artificial and Natural Soil Selection, Preparation and Evaluation ............................. 21 5.4 Emission Factor Measurements at UCR :..................................... ............................... 21 5.5 Emission Factor Measurements in Fresno ................................... ............................... 22 5,6 Quality Assurance Audit ................................................ :............................................ 22 6.0. DATA PROCESSING AND ANALYSIS ............................................... ............................... 23 6.1. Data Handling ............................................................................. ............................... 23 6.2 Data Validation ............................................................................ ............................... 23 6.3 Data Analysis ............................................................................... ............................... 24 7.0 EMISSION INVENTORY ..................... ................................................................................. 25 Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT 8.0 REPORTING ...................................... ............................... 9.0 REFERENCES ................................... ............................... Revision: 2 November 18, 2005 ............... ............................... 26 ............... ............................... 26 Table 1. Accuracy and Precision Objectives ................................................... ............................... 9 Table2. Matrix of Tests ................................................................................. ............................... 22 FIGURES Figure 1. Project Organization ......................................................................... ............................... 5 Figure2. Project Schedule ............................................................................... ............................... 7 FigureI Test Chamber .................................................................................. ............................... 16 Figure 4. Top View of Test Chamber Showing Test Material and Collection Area .................... 19 11 Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT 1.0 INTRODUCTION 1.1 Introduction Page 3 of 27 Revision: 2 November 18, 2005 This Quality Integrated Work Plan (QIWP) presents the overall project plan, study design, organizational assumptions, and quality assurance activities in the performance of this research project to determine particulate matter emission factors for leaf blowers. This project, is being performed by the University of California at Riverside - College of Engineering Center for Environmental Technology (CE- CERT), under contract with the San Joaquin Unified Valley Air Pollution Control District (District). This QIWP describes in detail the necessary activities to ensure that the-data coilected and reported are sufficiently complete, representative, precise, and accurate. It also provides the framework for implementing project QA and QC activities by addressing topics such as responsible individuals, data integrity, documentation, preventive maintenance, and corrective actions. This study is being performed to develop a method and equipment to determine air borne particulate matter (PM) emission rates from leaf blower activities. Once the method has been demonstrated to be viable, emission factors for a variety of leaf blowing activities will be determined. An emission inventory for the counties within the District will be prepared using activity data and the emission factors determined in this study. 1.2 Background Particulate matter (PM) has been implicated as being responsible for a wide variety of adverse health effects that have been shown in epidemiological studies to contribute to premature deaths (Pope et al. 1995). Many areas in the State of California _consistently exceed both the State and Federal PM10 and PM2.5 ambient air quality standards. To formulate effective mitigation approaches, the sources of the PM must be accurately known. Receptor modeling has shown that PM10 of geologic origin is often a significant contributor to the concentrations in areas that are in non- attainment (Chow et al., 1992). These geologic sources are generally fugitive in nature and come from a wide variety of activities that disturb soil or re- entrain soil that has been deposited. Leaf blowers are an obvious source of particulate emissions. The emission rates, however, have never been quantitatively measured and there is no default emission factor in AP -42 for this source. Botsford et al. (1996) estimated an emission rate by making assumptions and applying engineering principles. These emission rate estimations have never been validated with actual measurements. Staff at the California Air Resources Board (California Air Resources Board, 2000) estimated leaf blower emission factors using the Botsford approach and the silt loadings Quality Integrated Work Plan Page 4 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision; 2 University of California, Riverside CE -CERT November 18, 2005 determined by Venkatram and Fitz (1998). These silt loadings, however, were measured in gutters of paved roads, which is not a typical substrate that leaf blowers are used to clean. The ARB estimates have also not been validated by experimental measurements. 1.3 Project Objectives The objective of this study is to develop an emission inventory for these sources using measured emission rates. The PM emission rates from typical leaf blowers under typical actual and simulated conditions will be quantified. These emission rates will be then be used to develop emission inventories for counties in the San Joaquin Valley. 2.0 PROTECT MANAGEMENT 2.1 Project Organization Organizational commitment is an essential element for developing and implementing a successful research project. At CE -CERT, the Principal Investigator will be kept apprised of all research program activities, from identifying the need to develop sound experimental designs to delivering data reports. Commitments to research activities, such as those described in this QIWP are made only after the activities are thoroughly reviewed and approved by the Principal Investigator. Figure 1 presents the organizational chart that shows the lines of responsibility and information flow for activities under this project. A listing of specific responsibilities of each position for this project follows. Quality Integrated Work Plan Page 5 of 27 PM Emission Factors and hiventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT November 18, 2005 Figure 1. Project Organization San Joaquin Valleywide Uivfied Air Pollution Control District Project sponsor Dennis Fitz Principal Investigator David Pankratz David Geinmill Mark Chitjian I I Lisa Arth Field Operations QA/QC I Emission Inventory Reporting Student Assistants Principal Investigator — De finis Fitz Manages project technical and administrative tasks • Directs, integrates, and schedules activities of the project team • Provides scientific guidance on measurement methods • Guides the overall approach for performing the experiments and verifying their results • Project's principal point of contact with the District • Issues monthly progress reports to the District • Presents findings from main study to the District Project Engineer — David Pankratz • Designs, obtains, configures, assembles, and tests the measurement and ancillary equipment • Verifies the viability of the system • Performs tests to determine emission factors of leaf blowers • Initiates corrective actions and notifies Principal Investigator and QA Officer if equipment performance exceeds established control limits • Validates data Quality Integrated Work Plan Page 6 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT November 18, 2005 ® Performs data analysis, interpretation and determines emission factors for leaf blowers and other equipment tested Project Engineer — Mark Chitjian ® Develops plan to perform emission inventory for leaf blowing activities in the District. Using emission factors determined from this project, produces an emission inventory for the counties within the District for each season Prepares a report of the findings Quality Assurance Officer — David Gernmill ® -Reviews the test protocols and test matrices with particular emphasis on its quality control components Reviews the fabrication, assembly, and operation of the test systems ® Conducts performance audits of the assembled measurement systems ® Follows up on all unsatisfactory performance to ensure that the appropriate corrective actions are performed Contract Manager for the District ® The District is the organization to which the results of the tests will be presented; the project objective is to deliver data of known and acceptable quality and quantity to meet the needs and requirements of the District Reviews the QIWP and conducts critical project reviews Interacts with CE-CERT Principal Investigator 2.2 Personnel Qualifications and Training General education of all project personnel lays the foundation for successful project implementation. It is not intended to provide detailed and specific knowledge of all components of the project, but it promotes an understanding of the nature of the overall project goals, ensuring that all personnel understand the part they are to play in the project. The measurements to be performed in this project are basically the same as those that CE -CERT routinely makes in ambient air and in smog chambers. The CE -CERT Principal Investigator has more than 30 years' experience in making measurements of gaseous and particulate air pollutants in a research environment and in managing research projects. He is the Principal Investigator of many PM studies either currently being performed or conducted in the past few years. Other staff members also have been involved with using air quality instrumentation, performing PM emission measurements and performing emission inventories. All project personnel will be familiar with the content of this QIWP, thus obtaining a project Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 7 of 27 Revision: 2 November 18, 2005 overview, including information on all functions of the measurement systems, from experimental design, objectives, sampling, and data validation and reporting. Where applicable, project personnel will review the SOPs applicable to their responsibility. In addition, if major revisions or enhancements are made to the QIWP and /or SOPS, all affected individuals must review those revisions at that time. 2.3 Communications Plan Each project team member is linked by e -mail correspondence, and thus kept abreast of all project developments and information. These team members include resident experts on the operations and monitoring equipment utilized for this study and /or had extensive experience developing new measurements methods, as-necessary for this project. In addition, periodic project meetings and conference calls will be held. In these meetings detailed technical information will be exchanged, project status will be discussed, and project direction will be assessed. 2.4 Project Schedule Figure 2. is a Gantt chart showing the schedule for the project. Initial measurement data will be delivered to the District by August 22, 2005. The final report for the project will be provided to the District by October 4, 2005. Figure 2. Project Schedule. Jul 2005 ;tea =,. = _ ._M Aug 2005 = Sep 2005 Oct 2006 M .z . Nov 2005 b!J N �" o o � o 0 o w Quality Integrated Work Plan Page 8 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT November 18, 2005 3.0 PROJECT ASSESSMENT, DATA QUALITY OBJECTIVES, CONTROLS AND CORRECTIVE ACTION 3.1 Project Assessments The point of contact for managerial project assessment is that of the Principal Investigators described in Section 2.1. These investigators are linked to the District contract manager. This link will provide timely reviews of the project experimental design and implementation. The project team is committed to achieving and maintaining the highest level of quality possible throughout the performance of this program. The data generated will be both technically sound, and, where appropriate, legally defensible. The former is an obvious requirement but is not, in and of itself, sufficient to defend the data against an adversarial inquiry. The latter will address, through documentation, the level of quality achieved. The quality of the project data will be maintained not only through the development and use of data quality objectives (DQOs), which place numerical limits on the quality control indicators, but also through the use of subjective science quality objectives. Science quality objectives are used to provide evaluations of the quality of the research project and goals of the study. Evaluations of all research activities by internal and external peer review will assure that the methodology, experimental processes, conclusions and recommendations provided by this project are scientifically sound. Assessments of the data quality generated on this project will be made by: Conducting internal performance and systems audits of the critical components of the experimental setup and data processing systems. where applicable, adherence to SOPs will be evaluated. The results of these audits will contain any suggested corrective actions, and be appended to the data interpretation reports generated in this study. U Independent peer reviews of thesis materials, reports, and papers resulting from this project. 3.2 Data Quality Indicators The establishment of data quality objectives (DQOs) is a systematic planning process, which is described in the EPA document, Guidance for the Data Quality Objectives Process, EPA QA /G4. Measurement perfonnance criteria (MPC) are the set of criteria for each measurement system that are used to achieve the DQOs. These objectives vary from instrument to instrument, and will depend upon the environment in which the instrument is operated, how close the measured data are to the detection limits, the time increments employed, and other similar factors. For the Quality Integrated Work Plan Page 9 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision; 2 University of California, Riverside CE -CERT November 18, 2005 instruments used on this study, DustTzak and filter PM samplers, the anemometer and pitot tube wind and air flow monitors and the tracer gas monitors, the MPC are established due to previous operation under similar conditions. This process will be followed in the development of the experimental design described in this QIWP. The objectives associated with this study will include accuracy, precision, minimum detectible limits, completeness, representativeness, and comparability. These indicators will be measured on many of the instruments and sampling configuration experiments performed on this project. The typical criteria will be used as indicators of error or bias in a data set. However, there are a number of additional indicators such as Inference of Analysis that can be used to analyze.the data, where appropriate. By the use of these indicators, the following objectives have been established for this-project: 1. The error of the project data will be quantified using tools and methodologies outlined in this and related documents. This will be accomplished by conducting calibrations on selected instruments, checks of the accuracy of the flow rate measurements, peer reviews of selected components of the experimental setup, and collocation of instruments to determine precision. These data will be used to refine the provisional accuracy and precision of the project data set. 2. Data generated will be of sufficient quality to facilitate comparison with similar. studies. The Project Engineers and Principal Investigator will perform the statistical evaluation of the data. 3. All project staff will. strive to provide the maximum quantity of data possible for the duration of the study to allow for robust comparisons of data (data completeness). A provisional completeness objective for this study is 90 % for each instrument for each sampling run. A very high level of coinmunication will be encouraged throughout the study. Raw data comparisons, will help identify instrumentation and operational problems. The accuracy and precision objectives for this main study are presented in Table 1. Table 1. Accuracy and Precision Objectives E ! X '�� f�"� V ��=Mqsj • • . wa 1 iii_� �'' �.... ••. •� ''' •� 11 r 1'e -� • e - -• �- 1'e Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 10 of 27 Revision: 2 November 18, 2005 Wind Speed 1 0,1 rn/s ±5% Collocation with hand -held anemometer ±5 % Pitot Air Flow Sensor 1 0.1 m/s ±5° Collocation with hand -held anemometer ±5° Each indicator is discussed below, as it will be applied to this project. The results of these analyses will provide estimates of the accuracy and precision of these measurements under the conditions in which the instruments are operated. Accuracy The accuracy of the DustTrak and C31-16 analyzers, plus all meteorological instruments will be determined from a performance audit conducted during the study. The audit will consist of challenging the analyzer with a test atmosphere from an independent source, or collocations of meteorological instruments with independent standards. Each report of these performance assessments will contain detailed audit procedures and results. The percent difference at each concentration will be calculated using the following equation: %Dif. = [(Y - X)/X] x 100 In this equation, X is the test value and Y is the corresponding instrument response. If the test consists of a multipoint comparison, the resulting data will be used to generate a linear regression equation in the following form: Y = Slope (X) + Intercept The slope, intercept, and correlation coefficient (r) from this analysis will be used to evaluate the accuracy of the analyzers. The accuracy objectives in Table I are also the provisional expected control limits for calibration results. Replicate calibration tests will be assimilated and an average and standard deviation of all the %Dif values will be calculated to provide revised estimates of day -to -day accuracy for each instrument. 6 Precision The precision of selected instruments will be either determined from analyses from collocated data or by replicate analyses of the same span gas over time, and will be determined from calculation of the %Dif from each collocation or replicate run using the following equation: %Dif. = 2(A - B) /(A + B) x 100 In this equation, A is the value from the instrument A and B is the corresponding instrument value reported from collocated instrument B. A series of replicate collocation checks will be assimilated and an average and standard deviation of the entire %Dif. values can be calculated Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page I 1 of 27 Revision: 2 November 18, 2005 for each measurement to provide a refinement of the precision estimates presented in Table 1. In addition, the results of these collocation tests will be plotted on dedicated control charts, enabling refinement of the control limits for each instrument for the main study. Further, this procedure will be used to establish the repeatability for selected experimental runs, as appropriate. Minimum Detection Limits The minimum detection limits (MDLs) are defined as a statistically. determined value above which the reported concentration can be differentiated, at a specific probability, from a zero concentration. For gas analyzers, MDLs will be determined by repeatedly challenging the analyzer with zero air, followed by span and multiple calibrations. Generally, the -MDL for measurements on this program is determined as -three times the -standard deviation of the instrument response when subjected to zero air. The MDL for each analyzer has been well characterized; this information is located in the appropriate analyzer manual. This information is verified through statistical evaluation of data from zero air checks, using the following: MDL = t(n-1,l -a = 0.99) * s In this equation, s is the standard deviation of the replicate zero analyses; t is the Student's t value appropriate to a 99% confidence level and a standard deviation estimate with n -1 degrees . of freedom. The MDLs calculated for each measurement will include all sampling and conditioning procedures and therefore will represent a detection limit that can be applied to the reported concentrations. Provisional detection limits for the instruments to be used in this study are presented in Table 1. e Completeness Completeness is determined from the collected data generated during the study using the following equation: Completeness = A - Do) /D. *100 Where D,, is the number of samples for which valid results are reported and D, is the number of samples that are scheduled to be collected. The provisional. completeness objective for this study is 90% for each instrument for each sampling run. ® Representativeness Representativeness generally expresses how closely a measurement reflects the characteristics of the surrounding environment. This will be verified by review of the sample probe placements Quality Integrated work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 12 of 27 Revision: 2 November 18, 2005 effect the measured values. Representativeness will also be determined by the variabilities in emissions related to soil types. a Comparability Comparability refers to how confidently one data set can be compared with another. It is the objective of this study that the generated data will be of sufficient quality to facilitate comparison with similar studies. This will require adherence to the data quality objectives of each criterion listed above. 3.3 Routine Controls and Procedures Control over the handling and operation of the project instrumentation will be maintained throughout this project. This section presents the types of controls that will be incorporated into the project probess. Where applicable, instrument manuals and SOPs will be utilized. a Documentation Procedures All relevant instrument calibrations, experimental procedures and observations will be recorded in dedicated project logbooks. Data sheets will be maintained for any collected samples and instrument QC checks. e Calibrations and QC Checks The calibration procedures for this project include criteria that include daily calibration frequencies for many of the instruments. The accuracy objectives presented in Table I are also the provisional calibration control limits for this study. When instrument performance is outside these limits, actions will be taken to re- calibrate or repair the instrument. The description, operation, and maintenance of calibration standards are included as part of calibration procedures. In addition, an ongoing records management system will be maintained so that the calibration status of all instruments is readily available and easily retrievable in the future. o Determination of Instrument Readiness and Precision During the periods between test runs on a given day, the air monitoring instrumentation will continue to operate so that the ambient concentrations will be measured. Analysis of these data will help establish the operational readiness of the instrumentation by comparison with the expected ambient concentrations. In addition, in the case of multiple analyzers for the same species, collocated monitoring under ambient conditions will enable determination of measurement precision. Linear regression analysis of the ambient data collected from pairs of analyzers will be performed before test runs. Minimum standards will be established for Quality Integrated Work Plan Page 13 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT November 18, 2005 correlation coefficients for each type of analyzer, within established concentration ranges to determine if they are operating correctly. Test runs will be aborted if critical analyzers are'found to not be operating correctly. 4.0 MEASUREMENT EQUIPMENT AND METHODS 4.1 Real -Time PM Monitors — .DustTraks Real -time total suspended particulate matter (TSP), PM10. and PM2,5 measurements will be performed using Thermo Systems Inc. Model 8520 DustTrak Aerosol Monitors. Impactors are used to perform the size cuts and the PM concentrations are then determined by measuring the intensity ofthe 90'scattering of light -from a laser diode. The instruments are calibrated at the factory with Arizona road dust (KIST SRM 8632), but the real -time data will be compared with the mass determinations from the filter collections. The instrument sample flow rate is 1.7 L /min. The time constant is adjustable from 1 to 60 seconds, and will be used in the one - second position. 4.2 Time- Integrated PM Measurements. using Filter Samplers Filter samples will be collected using custom sampling systems designed by UCR for the collection of total suspended particulate matter TSP, PMIO and PM2.5 samples. A single.rotary vane pump will provide the vacuum to draw air through six filter media, two with each size cut. The sampler has six flow meters with metering valves for controlling and monitoring the flow rate through each sample media. The samples will be collected on 47 mm Gelman Teflo filters with a 2.0 µnn pore size. A Cahn Model 34 microbalance at the CE -CERT laboratory will be used to determine the weight of the filters to within I µg before and after sampling. All filters will be equilibrated at 23 6C and 40% RH for at least 24 hours prior to weighing. 4.3 Wind and Air Flow Rate Measurements e Wind Speed and Wind Direction Prevailing winds for testing performed at CE -CERT will be determined using a wind system located at a height of 5 meters at CE -CERT. A C114matronicsF460 wind speed and wind direction monitoring system will be connected to a Campbell l OX data logger. This system will measure and' process winds into hourly averages. The system has an accuracy of + \ -5 degrees for wind direction and +1-5% wind speed accuracy for winds greater than 5 m /s. Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 14 of 27 Revision: 2 November 18, 2005 Propeller Anemometer Measurements of Air Flow Through Test Chamber For testing performed with the test chamber ends open (tunnel mode), the mean air flow rate through the tunnel will be measured and continuously recorded using a Model 27106 Gill propeller anemometer. The wind sensor will be placed in the test chamber and oriented to measure air flow through the chamber. It will output wind speed (i.e. air flow rate) data to a data logger recording the data once per second. 4.4 Propylene Tracer Gas Measurements For testing performed with the test chamber ends open (tunnel mode), the air flow rate through the test chamber measured by the propeller anemometer will be checked using a tracer gas. Pure Propylene will be metered into the tunnel approximately 1 -2 meters in from the upwind end using a mass flow controller. Measurements for this tracer gas will be performed using a RAE Systems ppbRAE hydrocarbon analyzer located 1 -2 meters in from the tunnel outlet. The instrument determines the concentration of hydrocarbons using a 10.3 electron volt photoionization detector (PID). The instrument has a lower detection limit for C3H6 of approximately 50 ppb. 4.5 Data Acquisition System Data from the following instruments will be collected using a laptop PC with LabVIEW software and appropriate A/D cards and RS -232 multiplexers. The logging and averaging periods for each channel will be set to one second. TSI DustTrak PM samplers Filter samplers (on /off condition) Gill Propeller Anemometer Data from the Climatronics WS /WD system will be collected using a Campbell 10X data logger. At the conclusion of each set of tests, all data will be transferred to a networked PC for storage and backup. 4.6 Leaf Blowers There are several categories of leaf blowers. For this project, we will procure one of each of the following: gasoline powered hand held, gasoline powered backpack and electric powered with blower and vacuum capability. We will procure these from a home supply store. We will select the ones that are most popular and most likely of the style to be in use in the San Joaquin Valley. Quality Integrated Work Plan Page 15 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT November 18, 2005 We have tentatively selected the following three leaf blowers as they have been identified as the most popular from a major supply store (Home Depot, 2005): i Black & Decker Model BV 4000 Hand Held Electric Blower /Vacuum • Echo Model PB 403 Gas Backpack Blower • Homelite Model 30 cc Vac Attack II Gas Hand Held Blower 4.7 Rakes and Brooms A rake and push broom will be procured for examining alternate methods to leaf blowers for this study. We will procure one new broom and rake from a major home supply store. We will attempt to select the ones that are most popular and most likely to be. used in place of leaf blowers. 4.8 Test Chamber For testing leaf blowers we will build a test chamber. The chamber will be 2m wide, 2m high and 20m long. It will be constructed using 1" PVC pipe and aluminum modular pipe and rail fitting. The chamber will be enclosed using polyethylene sheeting. Figure 3 is a sketch of the chamber. Two different configurations of the system are being considered. The first is the "tunnel mode" with the system to be open at the two ends and for air to flow through with the prevailing winds. The second is for the "chamber mode" with the system to be fully enclosed. Testing and determination of which configuration will be used for the emission factor determinations are discussed in the next section. Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 16 of 27 Revision: 2 November 18, 2005 1 2 3 4 5 8 7 8 9 1011 121314151817181920 rasters long x 2 meters till x 2 meters wide Figure 3. 'Pest Chamber. 4.9 Safety Instruments ® Confined Space Gas Detector A three gas monitor (lower explosive limit, oxygen and carbon monoxide) will be placed in the test chamber to alert test crews of potentially dangerous levels of the latter two gases due to the leaf blower operation. An appropriate instrument will either be borrowed from the UCR Environmental Health and Safety Group or rented. ® high Concentration Particulate IN/latter Sensor The output of one of the DustTraks measuring TSP inside the test chamber will be monitored or configured to set off an alarm if PM levels .approach levels that are unsafe for project staff to be in without respiratory protection gear. 4.10 Soil Silt Content CE -CERT has soil from three agricultural facilities located in three different areas of the San Joaquin Valley as well as soil from VCR's agricultural facility in Moreno Valley from a previous study. We plan on using these soils in the present study. We had aliquots of all of these soils analyzed for silt content using the following two methods. Quality Integrated Work Plan Page 17 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT November 18, 2005 O AP -42 Soil Analysis Method The current protocol used by most agencies to estimate the amount dust entrained from agricultural tilling and from dirt roads is presented in AP -42 (EPA, 1995). Appendix C.2 of AP -42 describes a dry sieve protocol to determine the percentage of mass that passes through a No. 200 sieve (75 µm) and to define this fraction the "silt content." Aliquots of soils from UC agricultural facilities in Shafter, Kearney, 5- Points and Moreno Valley and artificial soils were analyzed by this method. ® Multisize Fraction Laboratory Analysis of Soils Aliquots of the above four soils all soils and artificial soils were analyzed by methods to provide more comprehensive particle size information (in particular for the —75 micron and smaller size diameters) than is provided by the Method AP -42 protocol. ASTM Method D422 (ASTM, 1990) was used to determine the sand, silt and clay content in the under 75 µm size range. This is a wet sieve method that uses sedimentation of the soil (or a sieved fraction of the soil) to determine diameter of the soil particles. 4.11 Fertilizer Spreader A fertilizer spreader will be used to spread our surrogate soil consisting of soil and grass clippings or leaves along ground inside the test chamber. A key selection criterion for the fertilizer spreader will be to find one with a spreading method that minimizes segregating the material based on size or mass as they are deposited. 4.12 Triple Beam Balance A model 710 -00 Ohaus triple beam balance will be used to weigh soil and vegetative matter used in the tests. The balance has a resolution of 0.1 grams. Quality Integrated Work Plan Page 18 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT November 18, 2005 5.0 MEASUREMENT PROGRAM The purpose of the measurements is to obtain emission factors for leaf blowers, rakes and brooms when used for cleaning over various surfaces. The first three sections below present the initial tests necessary to obtain a viable system for performing measurements to determine these emission factors. 5.1 Design and Evaluation of Test Chamber Designing, constructing and testing a system for determining PM generation from leaf blower operation is the first task in the measurement program. The initial plan for the test chamber is shown in Figure 3 and the tunnel and chamber configurations are discussed in Section 4.7. A test chamber configuration has several advantages over the tunnel. A major advantage of the chamber is there is no need to determine the air flow rate through the test apparatus. However, characterizing PM concentration differences throughout the tunnel becomes important as it is a closed system and it is the calculations will be based on accurately knowing the total amount of mass in the air in the test chamber. We will initially pursue the program using the chamber method for the following reasons: We believe that we will be able to accurately quantify the entire amount of mass in the chamber The chamber method eliminates the need to quantify the air flow rate through the measurement system The chamber method does not need winds to be present or blowing at any particular speed or in any particular direction Should the chamber method be found not to be viable, then we will pursue testing and evaluation of the open end tent method. The remainder of this section will discuss testing using the chamber method. 5.1.1 Viability of Structure Material will be laid out as shown in Figure 4. A leaf blower will be used to sweep the material 'into a collection area at the end of the structure. Observations will be made for the following: o Losses along the length of the structure due to using round pipe at the bottom o Losses under the length of the structure due to non flat surface — integrity between ground and pipe running along ground not maintained o Too copious of dust plume created; unsafe work environment. o Too high of exhaust buildup in chamber — unsafe work environment Quality Integrated Work Plan Page 19 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT November 18, 2005 o Ability /inability to sweep dirt due to shape /dimensions of test chamber Any problems found will be addressed as necessary. 1 2 3 4 5.6.:.,7.8.9 :10 ;.1112.13.:14.....15161718.1920 Figure 4. Top View of Test Chamber Showing Test Material and Collection Area. 5.1.2 Determination of Amount of Material to be used The amount of material to be used will be varied to determine the lower limit and range that can be used to provide responses on the DustTraks that significantly above their detection limit, allowing emission calculations with minimum uncertainty from the DustTraks. The material will be soil from at least one of the UC research areas in the San Joaquin Valley. We will also evaluate soil from the Fresno area if supplied by the District. We will determine the silt content of this soil. All material-used will be weighed before it is laid out. 5.1.3 Dust Plume Characterization Material will be laid out as shown in Figure 4. All DustTraks will have their impactors removed so that they are all measuring TSP. They will be placed at a height of Im at the following distances in: 2m, 5m, l Om, 15m, 17in, and 20m. The DustTraks will be hooked up. _to the data logger and one- second data will be recorded. A leaf blower will be used to blow the material into a collection area at the end of the chamber. The DustTrak data will be reviewed to determine plume characteristics across the chamber. The test will be repeated several times. The test will also be repeated with PMjo and PM2.5 inlets on the DustTraks. Three DustTraks will be placed 10m in at heights of 0.5m, 1.Om and 1.5m and three DustTraks Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 20 of 27 Revision: 2 November 18, 2005 will be placed in at 15m at the same three heights. The above tests will be repeated with TSP, PMIO and PM2.5 inlets to obtain vertical profile data. The findings from these tests will be used to determine the minimum number and placement of PM samplers in order to perform subsequent tests. Although the findings from these tests may determine otherwise, we will presume that six DustTraks, two for each particle size cut, are sufficient for the study. We will also presume that placing the samplers at a height of 1.5 meters height and at distances of l Om and 15m in is appropriate. Filter samples will be collocated with these six DustTraks for collection of samples on filter media on a daily basis. 5.1.4 Mass Balance A series of tests will be performed to determine if it is possible to account for all of the material that is swept in the test chamber. The following steps will be performed several times: • Weigh out material • Spread out on ground in chamber as shown in Figure 4 • Use leaf blower to sweep into collection area at end of chamber • Vacuum material from collection area and weigh • Collect concentration data inside chamber using DustTraks • Calculate total suspended mass using concentration data, volume of test chamber and plume profile characteristics • Determine how well start mass is accounted for Several of these tests may be performed, varying the amount of material deployed from zero to larger numbers and possibly using other materials, such as CaCO3 with a known nominal diameter, as necessary in order to understand any mass imbalances. 5.2 Real -Tune Ply Sampler Collocated Testing The DustTraks will be collocated and operated for several hours measuring ambient air or chamber air after some dust has been generated, as appropriate, to check that their responses are the same, within the instrument's stated accuracy and the accuracy goals of this project. The collocated tests will be performed for TSP, PMIO and PM2,5 operation. Instruments not performing as necessary will be repaired or excluded from the project. Quality Integrated Work Plan Page 21 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision; 2 University of California, Riverside CE -CERT November 18, 2005 5.3 Artificial and Natural Soil Selection, Preparation and Evaluation e Crustal versus Vegetative Mass Ratio of Test Material A range of the mass of soil to be used for this study will be determined as described in Section 5.1.2. We will vacuum measured areas at. selected locations around UCR where leaf blowers are routinely used just prior to routine leaf blowing activities. The. vacuumed material will be separated via sieves into crustal components and vegetative components (leaf, grass, etc). The separated components will be weighed to determine the relative masses of the two components. The average or median, as appropriate, of the ratio of the two masses of the two components will be used for preparation of subsequent soil samples standards. a Preparation of Surrogate Material Using the crustal /vegetative ratio determined above, surrogate soils will be prepared using the soils from the four UC facilities and that supplied by the District. Separate samples with grass and leaf material will be made for each of the soil samples. The material will be spread out as shown in Figure 4 and a leaf blower will be used to sweep the material into a collection area at the end. The collected material will be weighed. Comparisons of the airborne PM levels and the mass of the material collected will be made between the four UC facility soils to identify any differences. The range of differences will be noted. If there are significant differences, additional tests on additional soils present in the District will be performed to obtain better emission data that is related to soil type and independent of blower type. For the emissions testing to determine emissions related to different types of blowers, brooms and rakes, the soil from only a single UC facility from the San Joaquin Valley will be used as it is desired to have just a single variable, type of sweeper, for those emission determinations. However, the testing will include, different vegetative material mixed into the single soil and also include sweeping over surfaces with the indigenous dirt and vegetative matter. 5.4 Emission Factor Measurements at UCR The bulk of the testing will be conducted in Riverside using the surrogate debris mixtures consisting of vegetative matter and soil from a UC facility in the San Joaquin Valley or supplied by the District, as discussed in the previous section Table 2 shows the test matrix. Each test will be repeated three times, the PM2.5, PMIO, and TSP emission rates being determined each time. Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT 'fable 2. Matrix of Tests. (each test run represented by an "x ") Page 22 of 27 Revision: 2 November 18, 2005 Equipment Used Concrete Driveway Concrete Sidewalk Asphalt Parking Lot Lawn Shrubs, Flower Beds Leaf Blower #1 xxx xxx xxx xxx xxx Leaf Blower #2 xxx xxx xxx xxx xxx Leaf Blower #3 xxx xxx xxx xxx xxx Broom Sweeping xxx xxx xxx xxx xxx Vacuuming, bag full xxx xxx xxx xxx xxx Vacuuming, Bag Empty xxx xxx xxx xxx xxx Raking xxx xxx xxx xxx xxx 5.5 Emission Factor Measurements in Fresno A location will be selected in Fresno area for performing additional emission. We have tentatively selected the University of California Kearney Agricultural Field Station in Parlier. The test chamber will be setup at the location, along with all PM measurement and data recording instrumentation. A matrix of tests similar to those shown in Table 2 will be performed. In order to verify that there are no systematic differences in the equipment due to the location. change, at least three runs will be performed with a single leaf blower over a single surface using the same surrogate material as used for the testing at UCR. All'subsequent testing will be performed using soil and vegetative matter material from the Fresno site under actual conditions (after a mowing or trimming activity). The results will be compared with those of similar tests in Riverside and the extent of bias due to location will be estimated using a non - parametric statistical test. 5.6 Quality Assurance Audit An audit of the particulate matter samplers will be performed. The audit will consist of determining if the filter sampler flow rates are within the within the project accuracy goals. Quality Integrated work Plan PM Emission Factors and Inventories from Leaf Blowers University of California; Riverside CE -CERT 6.0 DATA PROCESSING AND ANALYSIS 6.1. Data Handling Page 23 of 27 Revision: 2 November 18, 2005 The Project. Team will maintain a dedicated record, which will clearly identify each instrument with its associated data input channel number. In addition, all periods of data collection, including the specific sampling, anode and any known problems with any of the instruments, will be logged at a sufficient level of detail in order to preclude misdirection of data. Data collected on the laptop PC will be transferred to a desktop PC for storage and backup on a daily basis. In addition, the -data management software enables- down - loading of the raw data directly into Excel spreadsheets, within which the data will be validated, analyzed, and archived. Power failures, instrument or computer failures, operator intervention for maintenance and calibration, deviation of the instrument. calibration results outside the acceptable limits, deviations of the QC checks outside the acceptable ranges, problems with the sample runs, or other problems are all factors can potentially compromise data validity.. The Project Team will identify those periods during which specific data may be considered unreliable by the use of data flags. When and if any of these factors occur it will be recorded in the project logbook and communicated directly to those performing the data validation and analysis. The data will be inspected graphically and all discrepancies and inconsistencies will be resolved by discussion within the project team and /or by reference to the raw data and the project logbook. 6.2 Data Validation Data validation will follow guidelines described by the U.S. Environmental Protection Agency (U.'S: EPA, 1978, 1980). All data will be screened for outliers that are not within the physically reasonable (normal), ranges. Next, the following steps will be taken: 1. Data will be flagged when'deviations from measurement assumptions have occurred. 2. Computer file entries will be checked for proper date and time. 3. Measurement data resulting from instrument malfunctions will be invalidated'. 4. Data will be corrected for calibrations or interference biases. Meteorological and DustTrak data will be reviewed as time series plots and using computer based outlier screening routines. Rapidly changing, anomalous or otherwise suspect data will be examined with respect to other data. Computer based outlier programs will be used to screen the data from the six DustTraks for anomalies (e.g. PM2.5 > PMIO, etc). Data will not be invalidated unless there is an identifiable problem or the measurement result is Quality Integrated Work Plan Page 24 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT November 18, 2005 physically impossible. Data values below detection limits will be entered to the database as the detection limit and flagged as a non- detect. For most of the measurements with fewer than 20 %o non - detectable values, the data analysis value will be set to one half the detection limit. For measurements and chemical species with a higher proportion of non - detectable values, the effect on the analysis of alternative treatments of these low concentrations will be evaluated. Approaches, will include setting the values to zero, the computed detection limit, and one half the detection limit. It is not anticipated that sufficient samples will be collected that will require imputation techniques for substituting these low values. The data reporting forms will contain a column for flagging and indicating the data validity. All problematic and missing data points will be highlighted in the form through the insertion of an appropriate coded flag. Invalidated data will not be placed in the reporting form in order to avoid their possible inadvertent use. These flags will include the following: • Valid value • Valid but comprised wholly or partially of below -MDL data • Valid but interpolated (value is above the highest calibration point) • Valid despite failing a statistical outlier test • Valid but qualified because of possible contamination or interference • Valid but qualified due to non - standard sampling conditions • Missing value because no data are available • Missing value because the data were invalidated by the operator The data will be checked for internal consistency, consistency with operator logbooks, and consistency with calibration zero and span checks, and instrument precision checks. Internal consistency requires that data fall within normal operating ranges and do not exhibit excessive and rapid variations that are inconsistent with expected variations. Consistency with operator logbooks requires that all data acquired during calibrations, maintenance, and outage periods be flagged appropriately. Consistency with calibration zero and span checks requires checking verified data against all calibration data to assure that reported data provides the most accurate possible measure of each parameter. All verified data that have been subjected to these tests will be designated as validated data. 6.3 Data Analysis The filter sampler data will be used to develop correction factors between the mass concentrations reported by the DustTraks and the concentrations determined by those determined from the filter data. These correction factors will be used to adjust the data measured by the DustTraks for the airborne particulate matter used in this project. Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page 25 of 27 Revision; 2 November 18, 2005 Emission factors will be calculated for the sweeping activities. We will be able to calculate both emissions in terms of airborne mass (TSP, PM,o and'PM2.5) per unit area swept and airborne mass per unit mass swept for all soil types and mixtures for all leaf blowers, brooms and rakes tested. These findings will be tabulated. Comparisons of the emission factors will be made to better understand variables effecting emissions as well as to perform a level 2 validation of the data. Final validated emission factors will be presented in manner that will be compatible with the emission inventory needs. 7.0 EMISSION INVENTORY Data oirthe area typically cleaned and the -time -spent at each task will be gathered from interviews with operators and observation of operators at work. Several residences, single family and multiple unit, and commercial location will be visited to estimate areas requiring cleaning From this data the area cleaned and the time spent per task will be determined for each unit of typical residence and commercial location For each season, s, the following calculation will determine a seasonal emission factor for each location type, 1. For each type of unit, single-family residence, multiple family residence and commercial unit, the typical area cleaned for each task will be multiplied by the emission factor for that task, t. This calculation will be repeated for each blower model type, m. For each task, t, the emissions will be summed over all model types, m. The resulting emissions for each task will be summed over all tasks to produce an overall emission factor for each location type. This calculation will be repeated for each season. Alts x EFtm = EFltsm Y_ EFitsm = EFlts Y_ EFlts = EFIs The amount of units of each type of residence will be determined from field H30, number of units in structure, from the 2000 US Census. The number of commercial locations will be determined as a ratio of the number of residences. This calculation will be repeated for each county (including the District portion of Kern county). The activity data produced for each county will be compared to other researchers estimates (Botsford 1996, ARB 2000). Adjustments to the activity data will be made where indicated. Finally, seasonal' emissions will be determined for each county (including the District portion of Kern county) by multiplying the number of units of each location type, by the emission factor for Quality Integrated Work Plan Page 26 of 27 PM Emission Factors and Inventories from Leaf Blowers Revision: 2 University of California, Riverside CE -CERT November 18, 2005 that location type, for that season, to arrive at the emissions for that county for that season. Ule x EFIs — Else Y_ Else — Esc 8.0 REPORTING Monthly progress reports will be issued to District that will review the work conducted and describe any problems encountered. This Quality Integrated Work Plan will be submitted for review and acceptance by the District prior to initiating measurements. A draft final report will be written and submitted to the District. A complete database of the activity and resulting emissions inventory, along with documenting assumptions and uncertainties, will be provided with this report. A final report will be prepared. The final report will incorporate the comments provided by the District in reviewing the draft final report. 9.0 REFERENCES Botsford, C.W., Lisoski, D., Blackman, W., Kam, W. (1996) Fugitive Dust Study — Characterization of Uninventoried Sources. Final report AV- 94- 06 -214A AeroVironment Inc. Monrovia, CA. March. California Air Resources Board (2000) A report to the California legislature on the potential health and environmental impacts of leaf blowers. February. Chow, J.C.; Watson, J.G.; Lowenthal, D.H.; Solomon, P.A.; Magliano, K.; Ziman, S.; and Richards, L.W. (1992) PM10 Source Apportionment in California's San Joaquin Valley. Atmos. Environ., 26A: 3335 - 3354. Fitz, D. R. and K. Bumiller (2000) Determination of PMjo emission rates from street sweepers. J. Air Waste Manage. Assoc. 50: 181 -187. Pope, C.A., Thun, M.J. Namboodiri, M.M., Dockery, D.W., Evans, J.S., Speizer, F.E., and Heath, C.W. (1995) Particulate air pollution as a predictor of mortality in a prospective study of U.S. adults, Any J. Respir. Crit. Care Med, 151: 669 -674. Venkatram, A. and D. R. Fitz. (1998) Modeling of PMIO and PM2,5 emissions from paved roads in California. Final report prepared for the California Air Resources Board contract 94- 336. March. Chow, J.C.; Watson, J.G.; Egami, R.T.; Frazier, C.A.; Zhiqiang, L.; Goodrich, A.; and Bird, A. (1990) Evaluation of Regenerative -air Street Sweeping on Geological Contributions to Quality Integrated Work Plan PM Emission Factors and Inventories from Leaf Blowers University of California, Riverside CE -CERT Page-27 of 27 Revision: 2 November 18, 2005 PM 10. J. Air & Waste Mffliage. Assoc. 40, 1134 -1142. Lowes (2005) Leaf Blower Buying Guide, www.Iowes.com /lowes /llcn? action= howTo& p= BLiyGuide /Icafblower.html &rn =Ri h� tNav Files/right.. Compilation of Air Pollutant Emission Factors, AP -42, Volume 1: Stationary Point and Area Sources, Fifth Edition, U.S.E.P.A.., Research Triangle Park, NC, January 1995. Standard Test Methods for Particle -Size Analysis of Soils, ASTM Method 422 -90. American Society for Testing and Materials. Philadelphia, PA, 1990. Home Depot (2005) Blowers and Accessories. RDUS/EN US /' JV JUl V11.11V Consumer Reports (2003) Power Blowers. Consumer Reports Magazine. Pg 44 -46. September. APPENDIX B: Audit of Filter Sampling Measurement System QUALITY ASSURANCE AUDIT REPORT Revision 0 Measurements of Particulate Matter Emission Factors and Inventories from Leaf Blowers Field Measurements Performed by: College of Engineering Center for Environmental Research and Technology University of California at Riverside Riverside, CA 92507 Audit Dates: September 8 and 27, 2005 Audit Performed by: David Gemmill Quality Assurance Officer College of Engineering Center for Environmental Research and Technology University of California at Riverside Riverside, CA 92507 CONTENTS 1.0 Introduction..... .......... ......... — .................... .......... .................... ................................. 1 2.0 Description of Measurement Sy stem ........................................................ ..............................1 3.0 Particulate Sampler Audit Procedures.. Equipment and Standards ............. ..............................1 4.0 Audit Results ........................................................................................... ..............................2 TABLES Table 1. Particulate Sampler Audit Results .................................................. ..............................3 I Quality Assurance Audit Report Pagel of 3 PM Emission Factors and Inventories from Leaf Blowers Revision 0 University of California, Riverside October 2, 2005 1.0 Introduction This report presents the results of a performance audit of an air particulate measurement system used on a project entitled, `Measurements of Particulate Matter Emission Factors and Inventories from LeafBlowers." The measurement system was designed to measure and determine particulate matter emission factors for leaf blowers. This project is being performed by the University of California at Riverside - College of Engineering Center for Environmental Technology (CE- CERT), under contract with the San Joaquin Valley Air Pollution Control District (District). Mr. David Gernmill, the Quality Assurance Officer for the UCR College of Engineering- Center for Environmental Research and Technology (CE- CERT), performed flow rate audits on the filter -based particulate samplers used on this project on September 8 and 27, 2005. Present for the audits was Mr. David Panlratz of CE -CERT, whose cooperation and assistance are grateftilly acknowledged. 2.0 Description of Measurement System The measurement system was installed and operated as described in the Quality integrated Work Plan (QIWP) for Measurements of Particulate Matter Emission Factors and Inventories fr o)n Leaf Blotivers, Revision 1, August 9, 2005. This QIWP presents detailed background information, project objectives, project management structure, measurement methods, study design, test chamber description, test instrumentation (leaf blower types), data acquisition and validation methods, and quality assurance objectives. The field operation generally consisted of operating the leaf blowers for a known time inside a test chamber containing soils and similar materials of very accurately known content. An array of particulate samplers was operated concurrently inside the chamber to characterize the resulting airborne particulate matter. The filter -based particulate samplers were configured in two separate systems, each containing a TSP sampler, a PMro sampler and a PMM2•5 sampler. These systems were designed and fabricated by CE -CERT. Each sampler system contains rotary vane pumps to provide the vacuum to draw air through the six filter media, and each system has four rotameters with metering valves for controlling and monitoring the flow rate through each sample media (the PM2.5 sampling system utilized two rotameters and valves). The target flow rate for the TSP and PM,o samplers is 16.7 actual liters per minute (ALM) and the target flow rate for the P1\42.5 samplers is 110 ALM. 3.0 Particulate Sampler Audit Procedures, Equipment and Standards The particulate mraplers are audited using the -procedures described in the Quality Assurance Handbook forAir Pollution Measurement Systems (EPA- 600- R- 941038b), Sections 2.10.7, and 2.12.10.2. The audit consists of tests of the accuracy of each sampler's flow rate. Further, the sampler is inspected for proper operation, leaks, cleanliness, and structural integrity. All gaskets and fittings are inspected, and the sample filter holders are inspected for integrity. Quality Assurance Audit Report Page 2 of 3 PM Emission Factors and Inventories fromLeafBlowers Revision 0 University of California, Riverside October 2, 2005 The audit standard for the TSP and PMIO samplers is a. Bios Model DC -1 HC flow meter, SIN 810. Its certification information is presented in each audit report. The B ios is an authoritative volume which meets all applicable KIST specifications. The audit standard for the PM2.5 samplers is an American Co. certified dry gas meter, SIN 8426721 The sampler's inlet is removed and an adapter fitting is attached to the downtube to which the audit standard is connected. The following are then recorded: 1. The flow rate as read by the sampler rotameter and converted to ALM by means of the latest calibration. 2. The flow rate as read by the audit standard and converted to ALM. The sampler flow rates are compared to the corresponding audit flow rates in percent difference, using the following equation: %Difl = [(S -A )/Al x 100 In this equation, S is the indicated sampler flow rate in ALM, and A is the measured audit flow rate in ALM. The satisfactory range for these audit results is a percent difference off10% or less. 4.0 Audit Results The audit results are presented in Table 1. The system for the PM2.5 sampler consisted of two pumps metered by two rotameters, plumbed together at the point where the filter media was attached. This configuration was necessary to achieve the 110 ALM flow rate required for this sampler. As shown in the table, the P1122.5 system was audited a second time because the target flow rates were not set correctly during the first audit. The audit results indicate that Of audit results are within the X10% satisfactory category. Quality Assurance Audit Report Page 3 of 3 PM Emission Factors and Inventories from Leaf Blowers Revision 0 University of California, Riverside October 2, 2005 Table I. Particulate Sampler Audit Results Sampler: 6 -Meter Rack Date: 09/08/05 Begin: 1416 End: 1520 Unusual Conditions: None v i sus ... >. ,. x.. TSP 18.4 40• 19.0 3.3 PMro 16.9 40 16.0 -5.3 PIVh.5 88 100, 100 83 -5.7 Sampler: 2-Meter Rack Date: 09/08/05 Begin: 14-16 End: 1520 Unusual Conditions: None v i sus ... >. ,. x.. TSP 171 40 16.0 -6.4 PMra 19.2 40 21.0 9.4 PIv12.5 91 100, 100 88 -3.3 Sampler: 2 -Meter Rack Date: 09/27/05 Begin: 0930 End: 1005 Unusual Conditions: None v i sus ... >. � 1 in` e x.. PM2.5 114 100; 160 112 -1.8 Sampler: 6 -Meter Rack Date: 09/27/05 Begin: End: 1005 1005 Unusual Conditions: None N, W PIv12.5 111 130, 130 lOS -5.4 (r) plow rates are presented in actual liters per ininute (ALM) (2) Audit standard for TSP and PMro: Bios Model DC -1 HC, Serial No. H810 (')Audit standard for PM2.s: American Co. dry gas meter, S/N 8426722 (3) Satisfactory criterion for difference between audit flow rate and sampler flow rate = ±10.0% r c Dri y o (D 3 * 0 r�, 3 iD o = 00 OO D A n m O N n O O ° 3 p (D p (D 7 (D (D O (D N n 0- 0 m r^ Z 0 Z Z (D P (D 0 (D 0 0 rD 0 0 m m -°1n 00 m S O (D [Oi O m N 7 r?p :3 d C 'O 1^ N O N d. 3 ? 0- �: C C �. (D N rt, ~ O CL m °° m `� Q' o°° 0 3 0 o ID a 3 -D o v M m DO v (D c "O s° DJ (D �, N w 'i0 Dl rCr y j. a :3 rD (D p of �• M N 0 N C N 3 3 ^ :° Q w p v a o 0 N .. D ° ° o n m ° n s D (D �, M (D =k rt 0 as rt m°° s m y (D o o ° < N 7 (O-'f• V N 0 ' N 7 -n 3• ° N O O N S 0) ° .(Dn 'D O N C. rt �,' O� 3' N rr ��-• �_ N n _�. S 00 '�". �. 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