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Region 1: EPA New England

School Bus Exhaust - Not an Idle Matter

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

By Robert Varney
September 3, 2002

Another school year is upon us and we all want to do our part to ensure that kids from kindergarten to high school have a healthy, safe, and productive school year. Our students will face numerous educational challenges ranging from learning to read and write, to learning a foreign language, to understanding complex mathematics.

As they prepare for their new adventures, there is one simple thing that we can do to help. By encouraging school districts to implement anti-idling guidelines for diesel school buses, we can help our children and everyone around them breath a little easier.

More than 1.7 million children in New England ride a school bus every day. While school buses are a safe and effective way to transport children to and from school, like all diesel vehicles, they emit pollution that is dangerous to breathe. Numerous scientific studies indicate that exposure to diesel exhaust can cause lung damage, respiratory problems, premature death and lung cancer. It also aggravates asthma, a leading cause of school absenteeism. Although everyone is affected by air pollution, children are more susceptible because they breathe 50 percent more air per pound of body weight than adults and their respiratory systems are not fully developed. Clearly, diesel fumes are not part of the recipe for an effective learning environment.

EPA is working to reduce pollution from school buses by setting very stringent emission standards that will take effect beginning in 2004. In 2007, new buses will be 95 percent cleaner than today’s models. In the meantime, reducing school bus idling is an important step for limiting the health effects of pollution from existing school buses.

In a study released last February, Yale University researchers in conjunction with Environment and Human Health Inc. found that children riding on school buses can be exposed to high levels of diesel exhaust. This increased exposure is directly related to idling school buses, which can compromise air quality on and around buses, including sidewalks, school yards, playgrounds and even inside school buildings. This is something we can change.

Although every school district is unique, there are some simple steps that schools can take to reduce idling time and air pollution. Some actions that school districts should take include:

Establish Idling Guidelines

  • When school bus drivers arrive at loading or unloading areas to drop off or pick up passengers, they should turn off their buses as soon as possible to eliminate idling time and reduce harmful emissions. The school bus should not be restarted until it is ready to depart.
  • At school bus depots, limit the idling time during early morning warm-up to what is recommended by the manufacturer and/or permitted by state anti-idling laws (generally three to five minutes). In colder climates, block heaters, which plug into electrical outlets, can help warm-up the engine to avoid starting difficulties and shorten warm-up time.
  • In the winter, provide a space inside the school where bus drivers who arrive early can wait.
  • If buses need the engine to run flashing lights during longer duration loading and unloading, consider installing an extra battery and changing the circuit configurations so that the flashing lights can be powered by the battery without the engine running.
  • Follow anti-idling laws and guidelines in your state. Currently, three New England states have anti-idling laws: Connecticut, Massachusetts, and New Hampshire.

Work Closely with Bus Companies and Bus Drivers to Implement the Guidelines

  • Make sure both the bus company and the bus drivers understand the importance of the new guidelines.
  • Highlight the economic benefit of reduced fuel consumption as a result of less idling. A typical diesel vehicle burns approximately one gallon of diesel fuel for each hour it idles. If a company operates 20 buses and each bus reduces its idling time by 30 minutes per day, at 80 cents per gallon of diesel fuel, the company would save over $2,000 per school year in fuel costs.
  • Establish a program to recognize drivers. For example, create buttons that drivers who pledge to follow the guidelines can wear, or give them positive recognition through school newsletters and events.

So, while you are preparing your kids for school, don’t forget to prepare the school for your kids. Talk to your school committee and school administrators about putting a stop to idling school buses. For more information, visit www.epa.gov/region1/eco/diesel/, or call: 1-800-821-1237.

Robert W.Varney is regional administrator of EPA's New England Office

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