Recently, the Natural Resources Defense Council and the Coalition for Clean Air released a report called "No Breathing in the Aisles: Diesel Exhaust Inside School Buses." The report is highly critical of air quality within the Nation's school buses. The report found that diesel fumes found inside the average school bus well exceed safe levels. The report calls such diesel levels carcinogenic and claims that a child riding inside a school bus inhales more diesel exhaust than a person riding in a car directly behind the bus.

"Children are especially sensitive to environmental hazards, yet they're the ones getting dosed with diesel riding to school," said Dr. Gina Solomon, NRDC senior scientist. "The levels we measured on some of these buses both surprised and worried us. Worse still, we have reason to believe that these high levels are fairly typical." The researchers rented four school buses and followed typical school bus routes in and around Los Angeles. What they found shocked and concerned them. The air quality both inside and outside the bus was tested, along with a comparison between buses with open windows and those with windows shut. Additionally, measurements were taken while the buses were idling, climbing and descending hills. The researchers relied on the assumption that the average child rides a bus one to two hours each day, 180 days each year for 10 years. The researchers found that the average child who rides a school bus is at least 40 times more likely to develop cancer than the child who does not.

"These monitoring results teach schools a tough lesson - they need to clean-up their bus fleets in order to protect the health of their kids," said Gail Ruderman Feuer, NRDC senior attorney. However, a trade group representing the school bus industry disputes the study's findings.

Such school bus pollution could be a major factor in the alarming increase in childhood asthma. Diesel fumes can enter the lungs and aggravate airways, causing or aggravating asthma. The researchers called for modification of diesel buses to allow them to operate on alternative fuels that are less harmful to developing lungs. "Diesel school buses remain the dirtiest option available on the market today," says Todd Campbell, policy director for the Coalition for Clean Air. Such a move could reduce exposure to cancer causing agents by up to 78%. Unfortunately, alternative fuels are often difficult to come by.

The researchers recommend that bus windows remain open when practical and that children sit towards the front of the bus.

The school bus industry has called the study a farce. "School buses are a great American success story, with a safety record that is unequaled in motor vehicle transportation. It would be unfortunate if any parent in California or elsewhere removes a child from a school bus in reaction to this story. Frightening parents and children about the safety of school bus transportation is an unfair way for the environmental advocates to promote their agenda and stoke the fires of debate about air quality in California," their statement said.