Diesel Fumes and School Buses
The "wheels on the bus" do go "round and round" but what the children's tune fails to tell us is that the engines on these buses also go puff, puff, puff. Each school day nearly 600,000 school buses transport 24 million students to and from school nationwide. The majority of buses are powered by diesel fuel creating exhaust that contains forty different compounds, which are listed as hazardous air pollutants under the Clean Air Act. Three of these chemicals are known human carcinogens. In fact, according to John Wargo, Professor of Risk Analysis and Environmental Policy at Yale University, diesel exhaust from school buses ranks as among the top five key threats to children's health, resulting from poor environmental conditions.
Children's lungs at risk
While the exposure to diesel exhaust fumes should concern the general public, the threat is even greater for children whose lungs are not yet fully developed. The low diameter particles in diesel exhaust are inhaled deeply into the lungs of children, penetrating their narrow airways, where they are more likely to be retained than in the lungs of fully-grown adults. Researchers have not determined whether there is a level of diesel exhaust exposure that is considered "safe" for children, particularly for those with respiratory illness.
Children spend an average of an hour per
day on diesel-powered buses, inhaling this
nasty mixture of pollutants and carcinogens.
And not only are children exposed to the
fumes from their buses but also those from
other diesel-engined trucks and buses on
their daily routes. Studies show that buses
sharing the road with other diesel-powered
vehicles have increased levels of exhaust
fumes within their own passenger compartments.
Additionally, buses line up and sit idling
in front of schools, spewing toxins into
the air. Children inhale these toxins as
stand in line waiting to board the buses
or even sit inside waiting for the buses
to depart.
Cleaning up the school buses
In the year 2000, the Environmental Protection Agency adopted new diesel regulations to address these concerns. The revised rules will eventually require reduced emissions from newer engines and the use of ultra low sulfur fuel. However, the rules will not be fully implemented until 2010, and even then older diesel vehicles will still be in use. Professor Wargo says "the tougher diesel regulations adopted are important, but insufficient to protect the respiratory health of children today. EPA's estimates did not account for the high exposures experienced daily by children while riding school buses, or from indoor pollution in homes, schools, and occupational settings. It seems unreasonable to wait any longer before taking steps to minimize diesel emissions from school buses."
Armed with this research Wargo has advocated for changes and new regulations, particularly in Connecticut. His efforts bore fruit when the Connecticut legislature passed an anti-idling statute. Now school busses are not allowed to sit idling for more than three minutes. He's also lobbied and won support for ultra low sulfur fuel - 15 part per million sulfur as opposed 300 parts per million a 20% reduction.
LINKS AND RESOURCES
Environmental Protection Agency
Natural Resources Defense Council
Environment and Human Health, Inc.
