WASHINGTON (AP) -- Most states aren't doing enough to protect children from the diesel exhaust many of them inhale while riding or waiting for school buses, an environmental advocacy group said in a report Wednesday.
No state received an A grade in the Union of Concerned Scientists' National School Bus Report Card, although it noted that many are working to cut school bus emissions, which can contribute to asthma and other respiratory ailments.
"School buses can be a major source of pollution exposure for children," said Patricia Monahan, an analyst for the group.
The Washington, D.C.-based organization advocates accurate scientific information in policymaking and sometimes takes liberal stances on issues.
After examining data supplied by all 50 states and the District of Columbia, the organization found that the district and Delaware, which received B grades, had the lowest rates of soot pollution: just over 9 pounds of pollution per bus last year. Fourteen other states also received Bs.
The worst polluter was South Carolina, closely followed by South Dakota. Both earned D grades, as did 11 other states.
Ninety-five percent of the nation's school buses are diesel-powered, and the group is recommending that they be refitted with fuel oxygenators or other anti-pollution equipment. The group also wants buses over 12 years old to be replaced by newer low-emission models.
"The oldest buses seem to pump out soot every time they climb a hill or accelerate," said Dennis J. McLerran, executive director of the Puget Sound Clean Air Agency in Seattle. Those buses produce as much as 20 times the pollution of newer models, McLerran said.
Several states are using alternative-fuel buses, replacing older buses with cleaner-burning models or retrofitting buses with devices that trap emissions. A considerably more low-tech method also can reduce children's exposure to bus pollution, especially as they wait in the parking lot for a ride home.
"We're recommending you just turn the engines off whenever you can," said Dwight Sinila, transportation director of Michigan's education department.
In Virginia's Fairfax County, officials returned to diesel buses about six years ago after buses that ran on cleaner compressed natural gas became unreliable.
"We couldn't get them out of the parking lots of the garages before they'd break down," said Linda Farbry, Fairfax's transportation director.
However, the county hasn't given up. By next fall, the entire fleet will be equipped with anti-pollution equipment. And in 2008, the county will begin testing a $160,000 hybrid diesel-electric bus. Until new equipment is installed, bus drivers are required to shut off engines if the buses are parked for more than a minute.