Diesel exhaust from trucks, buses and cars is composed of vapors, gases and fine particles (Note: diesel exhaust contains 20-100 times more particles than gasoline exhaust). Federal agencies have classified some of these components as known human carcinogens and hazardous air pollutants under the Clean Air Act.

Although it is well known that exposure to diesel exhaust can exacerbate respiratory diseases through inflammation and irritation of the airways, a recent EPA report concluded that diesel exhaust probably also causes lung cancer: "Overall, the evidence for a potential cancer hazard to humans resulting from chronic inhalation exposure to [diesel emissions] is persuasive." There is no known safe level of exposure to diesel exhaust. A recent study on children's exposures to diesel exhaust from riding school buses suggests that regulations regarding idling and maintenance are urgently needed.

The case for replacing diesel with cleaner and renewable fuels should also be proposed to our decisionmakers. Biodiesel is one alternative fuel that has gone through rigorous testing for health and environmental effects. This fuel, made from vegetable oils (primarily soybean), can reduce targeted cancer-causing compounds by up to 90 percent. In addition, biodiesel works in diesel engines with little or no modifications. A second alternative is low sulphur fuels. While conventional diesel can contain upwards of 700 ppm of sulphur, low sulphur fuels, often called 'cleaner diesel' or 'green diesel', contain no more than 30 parts per million (ppm) of sulphur. Low sulphur fuels produce less emissions of particulates, nitrogen oxides, volatile organic compounds (VOCs) and carbon dioxide. It is estimated that using low sulphur fuels would be the equivalent of removing two million vehicles from our roads.

For a comprehensive look at the problem of diesel exhaust at schools, please see the ChildSafe School Program

WEB RESOURCES

National Biodiesel Board
www.biodiesel.org
The national trade association representing the biodiesel industry as the coordinating body for research and development in the US.

Diesel Exhaust and Your Health
www.epa.gov/region1/eco/diesel/health_effects.html
A fact sheet by the US Environmental Protection Agency (EPA) for the New England region that documents the health and environmental effects of diesel exhaust.

Clean Air Council
www.cleanair.org
Based in Philadelphia, the Clean Air Council is a member-supported, non-profit organization protecting the right to clean air via public education and community advocacy.

Environmental Health Effects of Diesel Engines
www.vpirg.org/campaigns/environmentalHealth/ dieselExhaust.php
The Vermont Public Interest Group identifies the health risks of diesel exhaust, proposes viable alternatives and provides a sample school bus idling policy.

PUBLICATIONS

Children's Exposure to Diesel Exhaust on School Buses by John Wargo, Ph.D. Environment and Human Health, Inc. (February 2002)

Diesel Trucks and Environmental Health, a report available from the American Lung Association of Metropolitan Chicago. Call for a copy at 1-800-LUNG-USA. (April 2000)

Exhausted by Diesel: How America's Dependence on Diesel Engines Threatens Our Health by Gina M. Solomon, Todd R. Campbell, Tim Carmichael, Gail Ruderman Feuer and Janet S. Hathaway. Natural Resources Defense Council (April 1998)