Diesel-powered school buses are as much a part of American education as recess and red brick buildings. Unfortunately, they also can be a major source of pollutants hazardous to bus drivers, mechanics and bus aides as well as students. Diesel fumes, for example, can cause or worsen asthma, already the most chronic childhood disease. In addition, diesel fuel poses risks to workers who drive and maintain buses.

The AFT’s health and safety program has raised the issue of diesel hazards with both AFT members and policymakers. A growing number of AFT bus drivers have attended a train-the-trainer module on ways to reduce diesel hazards, and AFT staff have been discussing cleaner alternatives to diesel-powered school buses with officials from the U.S. Environmental Protection Agency. The information that follows is taken from materials prepared by staff in the national union’s health and safety program.

Exposure to diesel exhaust can lead to a wide range of health problems, from mild irritation to cancer. Short-term effects include eye, nose and throat irritation, runny nose, sneezing and coughing. Most symptoms clear up when the exposure ends. Evidence is mounting, however, that longer-term exposure can seriously affect the immune system and trigger asthma attacks in vulnerable individuals. What’s more, some evidence links extended long-term exposure with greater risk of lung cancer. Exposure to vapors from diesel fuel can be equally hazardous. Clearly, then, efforts should be made to reduce or eliminate diesel exposure.

Ideally, school systems should purchase new lower-polluting diesel vehicles or engines that have reduced emissions. Short of that, there are ways to reduce exposure with older buses, both inside garages and out on the road:

• Fuel pumps should be equipped with vapor capture devices to keep vapors away from workers’ breathing zones.

• Wearing gloves, preferably made of nitrile or viton rather than vinyl, can reduce exposure.

• Exhaust systems should be designed to ensure that mechanics and maintenance staff are not overexposed.

• In facilities without an exhaust system, hoses that vent to the outdoors should be connected to the tailpipe of any bus running inside.

• Buses should have frequent tune-ups, and exhaust systems should be regularly maintained and checked for leaks.

• Buses should be fitted with emission-control devices such as collectors, scrubbers and ceramic particle traps, and air cleaners should be replaced regularly.

• If a bus must idle for a long time, drivers shouldn’t be in it. Better yet, buses shouldn’t idle for extended periods.

• Vehicles should be checked for cracks that would allow exhaust to seep into the bus, and all cracks should be repaired.

• Buses should use the cleanest-burning fuel available (grade 1K).

Unfortunately, there are no Occupational Safety and Health Administration (OSHA) standards for exposure to diesel fuel or exhaust. Diesel fuel is covered under “right to know” standards, which means employers are required to implement a training program for workers on hazards and protective measures.

For their part, school districts should develop a comprehensive program to protect workers exposed to diesel fuel and exhaust. Where they exist, local health and safety committees can help identify jobs that put workers at risk of exposure, discuss methods to control exposure and recommend best practices to the district.

For more information on diesel or on health and safety committees, contact the AFT’s health and safety program at 202/393-5677.