Children's Exposure to Diesel Exhaust on School Buses
2/1/2002
In the United States nearly 600,000 school buses transport 24 million students to school daily. Each year buses travel 4.3 billion miles as children take nearly 10 billion school bus rides. If rides average 30 minutes in each direction, students will spend 180 hours on buses each year. Collectively, U.S. children spend 3 billion hours on school buses each year. More than 99 percent of U.S. school buses are powered by diesel fuel. Diesel exhaust is comprised of very fine particles of carbon and a mixture of toxic gases. Federal agencies have classified diesel exhaust as a probable human carcinogen. Benzene, an important component of the fuel and exhaust, is designated to be a known human carcinogen. Components of diesel exhaust are genotoxic, mutagenic, and can produce symptoms of allergy, including inflammation and irritation of airways. There is no known safe level of exposure to diesel exhaust for children, especially those with respiratory illness. This study concludes that the laws intended to control air pollution in the U.S. must be strengthened to protect the health of children in several important respects. First, fixed monitoring facilities do not capture the variability in air pollution experienced by children. Second, air quality inside buildings and vehicles is not regulated by the EPA. Third, tougher diesel regulations adopted by the EPA last year are insufficient to protect health. Fifth, routine emissions testing for school buses is not required by federal law.
Authors: Wargo, J. Ph.D.; Brown, D. Sc.D.