Mobile Source Air Toxics

This web page presents information on mobile source air toxics and strategies for reducing risk to the public from these pollutants.

For further information or assistance regarding this web page, contact:
the Assessment and Standards Division (ASD) Information Line, phone: (734) 214-4636 or email: asdinfo@epa.gov.

Archive for Mobile Source Air Toxics

About PDF Files

Index of Topics:

• What are Mobile Source Air Toxics?
• What is EPA Doing About Mobile Source Air Toxics?
• What You Can Do
• Assessment
  • Risk
  • Emissions
  • Air Quality & Exposure Monitoring
  • Health Effects
  • Modeling & Analysis Tools
  • Technical Analysis Plan
• Regulations
  • Regulatory Documentation
  • Implementation Support
• Reducing Risk in Communities

What Are Mobile Source Air Toxics?

Mobile source air toxics are compounds emitted from highway vehicles and nonroad equipment which are known to cause cancer or other serious health and environmental effects. In a 2001 rulemaking, EPA identified 21 air toxic compounds emitted from mobile sources.

• Fact Sheet: "Air Toxics from Motor Vehicles" (EPA400-F-92-004, August 1994) 13.2K PDF (5 pages)
  
  
• List of 21 Mobile Source Air Toxics
  
  
• March 29, 2001 Final Rule to Control Emissions of Hazardous Air Pollutants from Mobile Sources
  
  
• Air Quality Planning and Standards EPA maintains a valuable online resource center for information regarding air quality, toxic air pollutants, health effects, technical reports, assessment data, regulations, and air quality programs. Particular areas of interest are:
  
  
  • About Air Toxics, Health, and Ecological Effects provides a wealth of information on health and ecological effects of air toxic pollutants.
    
    
  • Health Effects Notebook for Hazardous Air Pollutants provides detailed information about the health effects of hazardous air pollutants (HAPs) available in separate fact sheets, for nearly every HAP specified in the Clean Air Act Amendments of 1990.
    

What is EPA Doing About Mobile Source Air Toxics?

By 2010, EPA's existing programs will reduce mobile source air toxics by over one million tons from 1996 levels. In addition to controlling pollutants such as hydrocarbons, particulate matter, and nitrogen oxides, EPA's recent regulations controlling emissions from highway vehicles and nonroad equipment also result in large air toxic reductions. Reformulated gasoline and anti-dumping standards, along with anti-backsliding provisions of the 2001 mobile source air toxics rule also result in large reductions. Finally, EPA has developed a variety of programs to reduce risk in communities, such as Clean School Bus USA, the Voluntary Diesel Retrofit Program, and Best Workplaces for Commuters.

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What Can You Do?

EPA has developed a variety of information materials on how you can help reduce emissions and exposure to air pollutants from mobile sources.

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Assessment

• Risk
• Emissions
• Air Quality & Exposure Monitoring
• Health Effects
• Modeling & Analysis Tools
• Technical Analysis Plan

Risk

• National Air Toxics Assessment includes results from the EPA National-Scale Air Toxics Assessment. The assessment includes 33 air toxics that present the greatest threat to public health in the largest number of urban areas, as well as diesel particulate matter, an indicator of diesel exhaust.
  
  
• Philadelphia Toxic Air Pollutants Risk Reduction Project EPA and Philadelphia Air Management Services are conducting a joint project called the "Philadelphia Toxic Air Pollutants Risk Reduction Project" to help reduce the threat to their health which Philadelphia's residents face from exposure to air toxics.
  
  
• Portland, Oregon Air Toxics Assessment EPA is helping to support this refined local scale assessment led by the Oregon Department of Environmental Quality.
  

Emissions

• National Toxics Inventory Data and Documentation provides county level inventory data for on-highway vehicles, nonroad sources, aircraft, commercial marine vessels, and locomotives.

Air Quality and Exposure Monitoring

• Air Toxics Monitoring centers around the exchange of air toxics monitoring-related information.
  
  
• California Air Resources Board School Bus Study was conducted to characterize the range of children's exposures to school by school buses.

Health Effects

• Integrated Risk Information System (IRIS) features a database of human health effects that may result from exposure to various substances found in the environment.
  
  
• Health Assessment Document for Diesel Exhaust includes the final health assessment document that examines information regarding the possible health hazards associated with exposure to diesel engine exhaust.
  
  
  • "Diesel Exhaust and School Bus Idling" (EPA420-F-03-005, April 2003) 442K PDF (2 pages) Fact sheet that looks at school bus diesel exhaust and school children.
    
    
• Discussion Paper on diesel health assessment issues.
  
  
• "Diesel Exhaust in the United States", (June 2003, EPA420-F-03-022) 412K PDF (4 pages) Fact sheet with overview of diesel exhaust health effects and options for reducing pollution from diesel vehicles.
  
  
• Clean School Bus USA: Human Health provides general information on health effects of diesel exhaust and who is at risk.
  
  
• These pages contain cancer and non-cancer inhalation risk assessment documents. Mobile sources account for the majority of nationwide emissions of these hazardous air pollutants.
  
  
  • Health Assessment of 1,3-Butadiene
  • Carcinogenic Effects of Benzene
  • Benzene (Noncarcinogenic)
  • Acrolein
    
    
• Air Toxic Substances Disease Registry is an agency of the U.S. Department of Health and Human Services that conducts assessments of health risks from a variety of substances.
  
  
  • ATSDR Toxic Frequently Asked Questions is a series of summaries about hazardous substances.
    
    
• Health Effects Institute is an independent, nonprofit corporation chartered in 1980 to provide high-quality, impartial, and relevant science on the health effects of pollutants from motor vehicles and from other sources in the environment.
  
  
• Toxicology and Environmental Health Information Program (TEHIP) is a comprehensive toxicology and environmental health web site that includes access to resources produced by TEHIP and by other government agencies and organizations.
  

Modeling and Analysis Tools

• MOBILE6.2 Toxics Module for MOBILE6 Highway Vehicle Emission Factor Model
  
  
• "Example Application of Modeling Toxics Air Pollutants in Urban Areas" (EPA454-R-02-003, June 2002). This report presents a case study of dispersion modeling in Houston for selected HAPs, using an approach which estimates highway vehicle toxic emissions along specific roadways.
  
  
• "The Projection of Mobile Source Air Toxics from 1996 to 2007: Emissions and Concentrations, Draft" (EPA420-R-01-038, August 2001). 3.0M PDF (56 pages)
  
  
• Support Center for Regulatory Air Models is EPA's source of information on air quality models for air toxics and criteria pollutants.
  

• Fate, Exposure, and Risk Analysis provides tools for evaluation of health risks from air toxics and criteria pollutants.
  
  
• Consolidated Human Activities Database contains human activity data for use in inhalation exposure assessment.
  
  
• Human Exposure Database System is an integrated database system that contains chemical measurements, questionnaire responses, documents, and other information related to EPA research studies of the exposure of people to Environmental contaminants.

Technical Analysis Plan

• As part of its April 2001 mobile source air toxics rulemaking, EPA identified four critical areas of research on mobile source air toxics where there are data gaps, and committed to a technical analysis plan to address these gaps. These areas were:
  
  
  • emissions of air toxics from nonroad sources
  • improved estimation of exposure in microenvironments
  • characterizing mobile source "hot spots"
  • improved understanding of effectiveness and costs of control strategies.
  • Summary of Key Research Projects
  • California Air Resources Board School Bus Study
  • National Training Workshop on Local Urban Air Toxics Assessment and Reduction Strategies, November 13-15, 2001 in Detroit, Michigan

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Regulations

Regulatory Documentation

Mobile Source Air Toxics Rule: Questions and Answers

• "Mobile Source Air Toxics Rule Questions and Answers" (EPA420-F-01-031, October 12, 2001)  69K WPD or 28K PDF (8 pages)

Final Rule to Control Emissions of Hazardous Air Pollutants from Mobile Sources (March 29, 2001)

• Federal Register Notice: Preamble and Regulations 290K PDF (45 pages)
  
  
• Press Release: "New Toxic Emission Standards Set for Gasoline" (December 21, 2000)
  
  
• Fact Sheet "Control of Emissions of Hazardous Air Pollutants from Mobile Sources" (EPA420-F-00-055, December 2000) 40K PDF (3 pages)
  
  
• "Technical Support Document: Control of Emissions of Hazardous Air Pollutants from Motor Vehicles and Motor Vehicle Fuels" (EPA420-R-00-023, December 2000) 570K ZIP WPD or 415K PDF (195 pages)
  
  
• "Control of Emissions of Hazardous Air Pollutants from Mobile Sources: Response to Comments" (EPA420-R-00-024, December 2000) 570K WPD or 415K PDF (140 pages)

Proposed Rule to Control Emissions of Hazardous Air Pollutants from Mobile Sources (August 4, 2000)

• Federal Register Notice: Preamble and Regulations 412K PDF (49 pages)
  
  
• Draft Technical Support Document (EPA420-D-00-003, July 2000) 502K PDF (162 pages)
  
  
• Fact Sheet: "Proposed Rule to Control Emissions of Hazardous Air Pollutants from Mobile Sources" (EPA420-F-00-025, July 2000) 13K PDF (4 pages

Implementation & Support

Guidance to Parties Submitting Mobile Source Air Toxics Baseline Applications

• "Guidance to Parties Submitting Mobile Source Air Toxics Baseline Applications" (EPA420-F-01-017, June 2001) 61K WPD  or 11K PDF (5 pages)
  
  
• Spreadsheet templates  14K XLS  or  5K WK4

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Reducing Risk in Communities

• Air Toxics Community Assessment and Risk Reductions Database has been compiled to provide a resource of planned, completed, and ongoing community level air toxics assessments around the country.
  
  
• Clean School Bus USA is EPA's national partnership to minimize pollution from school buses. Leaders from corporate America, children's health, environmental and governmental organizations gather to design a plan to reduce children's exposure to diesel exhaust by eliminating unnecessary school bus idling, installing effective emission control systems on newer buses and replacing the oldest buses in the fleet with newer ones. For more information contact the Clean School Bus USA Team at (734) 214-4780 or email: CleanSchoolBusUSA@epa.gov.
  
  
• EPA's Voluntary Diesel Retrofit Program works to reduce pollution, including air toxics, resulting from existing diesel vehicles and equipment by encouraging fleet owners to install pollution-reducing devices on the vehicles and to use cleaner-burning diesel fuel.
  

• Best Workplaces for Commuters is a public-private sector voluntary program offering innovative solutions to commuting challenges faced by employers and employees. Reducing vehicle miles traveled is an effective way to reduce air toxics risk in communities.
  
  
• Clean Air Transportation Communities Grants Program supports voluntary cooperative projects that promote transportation efficiency measures within the United States, encourage development patterns that reduce the growth in vehicle miles traveled, and expand the availability of environmentally-sensitive transportation alternatives.
  
  
• Green Communities is designed to help communities access the tools and information that would help them become more sustainable, green communities.
  
  
• Tools for Schools program is a comprehensive resource to maintain healthy air in school buildings by identifying, correcting and preventing indoor air quality problems.
  
  
• Cleveland Air Toxics Pilot Project
  Fact Sheet (May 2003) EPA selected Cleveland to host the first demonstration of a new approach to air toxics control that will serve as a model for communities nationwide. The pilot will address pollutants from many sources, both indoors and outdoors, and will put into place a risk reduction program to combat serious urban toxic air pollutants in the city. The project has three goals: reduce risks from air toxics in Cleveland within a year, ensure the project is sustainable, and ensure the approach can be replaced by other communities.
  
  
• Portland, Oregon Air Toxics Assessment EPA is helping to support this refined local scale assessment led by the Oregon Department of Environmental Quality.
  
  
• Philadelphia Toxic Air Pollutants Risk Reduction Project EPA and Philadelphia Air Management Services are conducting a joint project called the "Philadelphia Toxic Air Pollutants Risk Reduction Project" to help reduce the threat to their health which Philadelphia's residents face from exposure to air toxics.
  

• "Example Application of Modeling Toxics Air Pollutants in Urban Areas" (EPA454-R-02-003, June 2002). This report presents a case study of dispersion modeling in Houston for selected Hazardous Air Pollutants (HAPs) using an approach which estimates highway vehicle toxic emissions along specific roadways.
  
  
• West Oakland Pilot Project This resident-led initiative resulted in a series of solutions for reducing exposure to diesel pollution in the heavily impacted West Oakland community.

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