School bus fumes may be to blame for the dramatic rise in asthma and other chronic respiratory illnesses among children across the country, according to a study released Feb. 7 by researchers from the Yale School of Forestry and Environmental Studies, Environment and Human Health Inc., and the University of Connecticut.

According to the report, children breathe school bus engine exhaust about 180 hours a year in the United States. For the thousands of children with asthma and other respiratory illnesses, exposure to diesel exhaust and the chemicals in it is cause for concern, said John Wargo, a researcher at the Yale School of Forestry and Environmental Studies.

“We’re not telling parents to keep kids off the bus,” Wargo said. “We are saying the ride to school could be healthier.”

The study calls on state and federal environmental authorities to crack down immediately on school bus emissions.

Wargo said components of diesel exhaust damage genes, cause mutations, and can produce symptoms of allergy, including inflammation and irritation of the airways

Exposure is worst when buses are lined up idling, picking up and dropping off students, and when buses are moving through heavy traffic, researchers found. Keeping bus windows closed increased the exposure.

Wargo and the other researchers tested 75 bus runs. During 27 bus runs along a rural experimental route with light traffic, all diesel buses had interior concentrations of emissions exceeding Connecticut’s 24-hour background rate for fine particles.

The highest concentrations exceeded background levels by nearly 10 times. Diesel fuel also contains 40 chemicals listed as hazardous air pollutants under the federal Clean Air Act.

The Connecticut Department of Environmental Protection (DEP) in January announced a pilot program to reduce diesel emissions from school buses through the use of low emissions fuels and pollution control features.

The Clean School Bus Program will debut in Norwich, Conn., during the 2002-2003 school year.

The DEP and Connecticut School Transportation Association also signed an agreement Jan. 4 to limit the amount of time buses can sit with their engines running while waiting to pick up students at schools.

Related links:
Yale School of Forestry and Environmental Studies

Environment and Human Health Inc.