Reducing school bus emissions: Driving Michigan toward a cleaner environment

June 25, 2019

Michigan schools are required to provide instruction in an environment free of debilitating contaminants, but older diesel buses that have not been equipped with clean diesel technology can expose children to harmful exhaust.

This is now changing through the Michigan Clean Diesel Grant Program, created by the Michigan Department of Environment, Great Lakes, and Energy (EGLE) to promote the use of cleaner fuels and technologies with the goal of reduced diesel emissions.

Diesel emissions from older buses may contribute to long-term damage to the environment and impact climate. The Michigan Department of Education recommends minimizing school bus idling time when parked to reduce student exposures to exhaust emissions. Because of this, EGLE supports the removal of older diesel school buses from the road.

Fleet operators are decommissioning and replacing their older diesel buses with new buses through Michigan's Clean Diesel Grant Program. Recently eight school districts in Michigan -- Fennville, Fowlerville, Hamilton, Hillsdale, Hopkins, Livonia, Ludington and Wayne-Westland -- were awarded a total of $626,573 in grants to help purchase 28 new buses. The new buses will use either clean diesel or propane technology, which will reduce kids' exposure to harmful exhaust fumes and particles from the buses while riding and when they are getting on and off. It also keeps the fumes from getting indoors, where children spend most of their day, since exhaust can be drawn into buildings as doors open and close.

Diesel emissions from older buses are not only immediately harmful to Michigan's children, but they contribute to long-term damage to the environment and climate.

Contaminants from diesel exhaust include more than 40 substances listed by the U.S. Environmental Protection Agency as either Hazardous Air Pollutants or Criteria Pollutants (or precursors to Criteria Pollutants, such as nitric oxides and nitrogen dioxide, both components of oxides of nitrogen). Both Hazardous Air Pollutants and Criteria Pollutants have known adverse health impacts on humans.

When oxides of nitrogen chemically react with volatile organic compounds in the presence of sunlight, it forms a short-lived, but very harmful lung irritant -- ground level ozone. Kids are vulnerable to this, as their lungs are still developing, and kids with asthma are particularly vulnerable. The Centers for Disease Control reports that 49 percent of children with asthma reported one or more asthma-related missed school days in 2013.

Particulate matter is another concern with diesel exhaust. This consists of tiny particles that are small enough to be inhaled into the deepest part of the lungs, where the contaminants are not easily coughed out and can come in contact with the blood stream. Since children have a faster breathing rate than adults and their lungs are not fully developed, these health risks can be as much as six times greater for children than adults. To illustrate the potential impact of this program, replacing one older diesel bus with a clean diesel bus in Hillsdale would reduce particulate matter by 98 percent per year, as calculated by the EPA's diesel emissions quantifier.

EGLE recognizes the need to support healthy kids by promoting the use of cleaner fuels and technologies through the Michigan Clean Diesel Grant Program. Resources and grant opportunities are available to act locally and think globally. Ensuring healthy lives and promoting well-being for all at all ages is a United Nations Sustainable Development Goal. Stay tuned for future opportunities in Michigan to support the use of cleaner, alternative fuels.

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