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EPA School Bus Study Shows Idling Worse Than Re-starting Engines

Release Date: 05/21/2007
Contact Information: Elias Rodriguez (212) 637-3664, [email protected]

(New York, N.Y.) Shut off those diesel school bus engines! That was the clear message delivered by Alan J. Steinberg, EPA Regional Administrator along with Congressman José E. Serrano today at a press conference held at Public School 48 in the Bronx. EPA studied school bus exhaust levels when the buses were parked but engines kept running and calculated the benefits from turning them off for various periods and then restarting them. The study concluded that idling for more than three minutes generates more pollution than stopping and re-starting the engine – debunking a widely held belief of some drivers. Turning the engine off cuts carbon monoxide, fine particles, nitrogen oxide, and carbon dioxide – a greenhouse gas.

“Pollution from school buses has health implications for everyone, especially asthmatic children,” said Alan J. Steinberg, EPA Regional Administrator. “This study shows in no uncertain terms that allowing a bus to idle exposes children to more pollution and shows that a very simple step – shutting off that engine – can really make a difference.”

Under the study, EPA measured the pollution from six buses owned and operated by the Katonah-Lewisboro School District of New York. The level of pollution from buses that idled for more than three minutes was 66% higher in fine particles than pollution generated from shutting off the buses and then re-starting them. Bronx community leaders and representatives from the New York City Department of Education and the New York Power Authority joined with EPA today in support of anti-idling efforts.

Diesel exhaust particles can penetrate deep into the lungs and pose serious health risks, including aggravating the symptoms of asthma and other respiratory problems in healthy individuals. The Northeast has some of the highest asthma rates in the nation, including childhood asthma rates near 12 percent in areas of New York City.

In the U.S., 24 million children ride the school bus every day. On average, students spend an hour and a half each weekday in a school bus. Nationally, school buses drive more than 4 billion miles each year.

Due to the longevity of diesel engines, it is estimated that about one-third of all diesel school buses now in service were built before 1990. Older buses are not equipped with today's pollution controls or safety features and are estimated to emit as much as six times more pollution as the new buses that were built starting in 2004, and as much as sixty times more pollution as buses that meet the 2007 diesel standards. There are steps that school bus operators can take now to reduce pollution levels including idling reduction programs, anti-caravanning practices, ensuring proper maintenance of engines, and replacing and retrofitting older buses.

EPA will continue to work with states and local agencies, including school districts, to promote idling reduction efforts and reduce harmful air pollution to protect our children and our communities. These and other projects are possible due to collaborative efforts like the Northeast Diesel Collaborative, a partnership of EPA and private, non-profit and government groups in New York, New Jersey, Puerto Rico and the six New England states working together to fight air pollution.

For more information about reducing pollution from school buses, visit EPA’s Clean School Bus USA website at: https://www.epa.gov/region02/cleanschoolbus/