'98 Year in Review: States

The effects of diesel engine exhaust became the top state story of 1998 after a panel of scientists from the California Environmental Protection Agency concluded that the smoke posed a cancer risk to humans (4-27, p. 1).

The California attorney general and environmental groups filed a lawsuit against four grocery chains, alleging that their truck fleets posed an excessive cancer risk to residents. Environmentalists said they wanted the businesses to switch to cleaner burning fuels like liquid natural gas.

The debate took a turn when scientists in Colorado released the Northern Front Range Air Quality Study, which found that gasoline engines created three times as much air pollution in Denver than did diesel engines (5-18, p. 1).

In an unrelated move, the California Air Resources Board resumed testing trucks for excessive exhaust smoke, with 14% of the vehicles failing to pass (6-22, p. 9).

A California state judge took some of the pressure off the trucking industry when he threw out a lawsuit filed by environmental groups against nine diesel engine manufacturers. The plaintiffs had sought to make the companies post cancer warning signs, which would have exposed them to huge civil penalties. But the judge ruled that the environmentalists had not shown that the engines created a cancer risk. (8-24, p. 1). That ruling has been appealed.

The air board reached a compromise between trucking and environmental interests when it listed certain elements of diesel exhaust as toxic airborne contaminants without calling the exhaust itself a pollutant.

For the full story, see the Jan. 11 print edition of Transport Topics. Subscribe today.