The Chattanooga-Hamilton County Air Pollution Control Bureau and First Student, Inc., a provider of student transportation, have successfully completed the Clean School Bus project. This project has resulted in a significant reduction of pollution from more than half of the school buses in Chattanooga and Hamilton County, helping to improve local air quality and reducing children's exposure to diesel exhaust.

The fine particles in diesel exhaust can penetrate deep into the lungs and pose serious health risks including aggravated asthma, lung damage, and other serious health problems. In addition, diesel exhaust is a likely human carcinogen. Children are more susceptible to air pollution than healthy adults because their respiratory systems are still developing and they have a faster breathing rate.

Bob Colby, Bureau Director said, "EPA's Clean School Bus USA program is a nationwide effort to reduce school bus emissions. We're proud to be a part of this effort to preserve our children's health."

A bumper sticker was created by the Air Pollution Control Bureau to go on the back of the buses. "We had a small portion of the grant left after the retrofit was completed and were able to use it for marketing," said Kelley Walters, PR Specialist for the Bureau. "We talked about several options, like brochures, but decided that the bumper sticker would be the best way to spread the word, especially with the kids, their parents and the school staffs."

Bus emissions were reduced by the application of diesel oxidation catalysts (DOCs), which are like catalytic converters on cars. DOCs use a chemical process to break down pollutants in the exhaust stream into less harmful components. They have been verified by EPA to reduce emissions from diesel combustion by the following amounts: particulate matter - 20%, carbon monoxide - 40%, hydrocarbons - 50%. The reductions from the diesel catalysts nearly doubled when the buses were required by the federal government to begin using low-sulfur diesel in 2006.

The Bureau was able to complete this project through a $100,000 grant from the U.S. Environmental Protection Agency's (EPA) National Clean Diesel Grant Program.

For more information on Clean School Bus USA, visit their website at www.epa.gov/cleanschoolbus.