By Frances Gilmore
Exhaust from idling buses can enter the school building through open doors and windows and ventilation intakes. If buses are idling while letting students on or off, exhaust can also enter the cabin, exposing students and the driver.
Because diesel exhaust is so toxic, New Jersey law restricts the amount of time school buses may idle. The New Jersey Department of Environmental Protection (NJDEP), however, encourages districts to eliminate ALL idling and to sign the “No Idling Pledge,” an agreement to implement several practices related to idling.
Pierrepont School in Rutherford is typical of many urban schools, in that six buses are parked alongside the building overnight. They idle before leaving to pick up students, exposing staff who are in the building early to dangerous fumes. As a way to eliminate idling next to the school, Rutherford’s UniServ field representative, Rose Ann Spina, explained that the local association has been seeking an off-site location agreeable to all parties for warming up the buses.
Idling next to a school is the main source of exhaust exposure to students and staff, but an old or malfunctioning bus can also emit exhaust into the cabin, exposing students as they ride. Such buses also pollute the communities they pass through.
Under NJDEP’s Mandatory Diesel Retrofit Program of 2007, the state paid to retrofit buses with a closed crankcase ventilation system (CCVS), designed to capture fuel vapors that escape from the engine and feed them back into the combustion process. The retrofits were completed in 2013.
According to NJDEP’s Bureau of Mobile Sources, buses manufactured since 2007 have closed crank cases and consequently one-tenth the emissions of pre-2007 buses. There should be no more noncompliant school buses in the state, unless a district or contractor purchased a pre-2007 bus.
The sidebar below outlines a strategy for eliminating bus idling. Note that air sampling is not included, as it is not a useful measure. It often fails to represent true exposures and may suggest there is no problem when there is one. This is especially true for substances that have no safe levels, as is the case for carcinogens. Diesel exhaust is easily detected without sampling. If exhaust odors are experienced inside the school, or in or around the buses, then exhaust is present.
Diesel exhaust is a mixture of thousands of gases and fine particles (soot) that are small enough to penetrate into the deep lung, where they can do major damage. Exhaust contains more than 40 toxic chemicals, including carcinogens such as benzene and formaldehyde, and other harmful pollutants.
Diesel exhaust exacerbates allergies and causes inflammation in the lungs, which in turn may cause coughing, an increase in the frequency or intensity of asthma attacks, and aggravate other chronic respiratory symptoms. Other acute effects include eye, nose, throat and respiratory irritation, headaches, light-headedness and nausea.
Children are much more susceptible to diesel exhaust, because their lungs are still developing and because they breathe more rapidly than adults. Children breathe 50 percent more air per pound of body weight than adults.
With a few exceptions, diesel school buses are prohibited from idling for more than three minutes. They are allowed to idle, however, for 15 minutes in any 60 minutes while actively loading and unloading passengers—even though NJDEP recommends no idling. Violations of the idling rules can result in fines of from $250 to $1,000 per bus per day, on the bus owner. The driver is not fined unless the driver owns the bus.
Local associations should consult with their UniServ field reps and work with their districts to ensure that school district transportation policies are in alignment with the law and that all school bus drivers are properly trained. If violations occur, local association officials can report them to the local health department.
Local associations are encouraged to work with their UniServ field representative to stop bus idling. Measures to take include:
- Turn off engines while waiting to load and unload students.
- Use newest school buses for longest routes.
- Maintain buses to eliminate any visible exhaust.
- Complete school bus driver training on eliminating idling.
Frances Gilmore holds a Master of Science degree in Industrial Hygiene from the University of Pittsburgh, and is a consultant with the New Jersey Work Environment Council, which is a frequent partner with NJEA on school health and safety concerns.