Union For Concerned Scientists : School Bus Pollution Report Card 2006 (website)

School buses are the safest form of transportation for children. Compared with cars or transit buses, school buses are involved in significantly fewer accidents, injuries, and fatalities. However, the pollution from older school buses may pose risks to children's health that tarnish the image of the familiar yellow school bus. The exhaust from diesel fuel, which powers about 95 percent of the more than 505,000 school buses on U.S. roads today, is linked with asthma, heart disease, cancer, and even premature death. Recent studies have found that pollution can concentrate inside school buses, leading to even higher exposures for children who ride buses. Luckily, today's cleaner fuels and pollution controls for diesel vehicles can dramatically cut pollution from school buses. Many states have made progress in reducing pollution, but we are still a long way from ensuring that our children are riding in "clean" school buses.

Southern Alliance for Clean Energy : A Safer ride to school, How to Clean Up School Buses and Protect Our Children 2005 (pdf)

In December 2003, Southern Alliance for Clean Energy and Clean Air Task Force conducted a study in metro Atlanta to measure and characterize the air quality inside school buses and demonstrate the benefits of pollution control technologies and clean fuels. From this research the SACE established a coalition of local activists, community groups, health professionals, teachers and schools to promote clean school buses and improve Atlanta's air quality.

Clean Air Task Force : School bus particulate matter study 2004 (website)

Diesel exhaust is a major source of combustion particles that contribute to poor air quality nationwide. Since almost all school buses are operated with diesel engines, diesel engine exhaust can thus also be a source of concern, specifically with regard to exposure to children. Diesel particulate matter (DPM) is a complex and unhealthy mixture of inorganic and organic carbon particles with adhered toxic substances and metals. The purpose of the study was to investigate the causes of school bus self-pollution and to document in-cabin diesel particulate matter exposures in buses retrofit with a variety of available particulate matter emissions control combinations. This is one of the first studies to report on the in-cabin benefits of retrofit technology. To date, our testing has been conducted on school bus fleets in three U.S. cities - Chicago, IL and Atlanta, GA in 2003 and in Ann Arbor, MI in 2004.

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. In Connecticut, 387,000 students ride to school each day on 6,100 buses. Most 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. This study concludes that the laws intended to control air pollution in the U.S. and Connecticut must be strengthened to protect the health of children.

SACE encourages school districts and other diesel fleets to use ultra-low sulfur diesel and to retrofit their vehicles with catalytic converters and particulate matter (PM) traps. These changes could help cut diesel emissions by up to 90 percent, thus preventing premature deaths every year and significantly reducing the number of respiratory illnesses suffered by children and other sensitive people. SACE works with area fleets to encourage investments in retrofit technologies and assisting with financial assistance.

National Resources Defense Council ; No Breathing in the Aisles Diesel Exhaust Inside School Buses 2001 (website)