Vapor lock: environmental regulators target diesel emissions.

• Author: Green, Kenneth

Diesel emissions, the fumes voted least likely to become a Glade air freshener, have come to the attention of environmental regulators. Guess what? The regulators don't like them. In fact, the regulators dislike them so much that they're working toward banning them altogether, though in greenspeak that's called "fostering the adoption of alternate fuels."

Touting recent findings that diesel emissions are YAC (Yet Another Carcinogen), several groups in California - a state that has consistently set national environmental trends - have stepped up their efforts to eliminate the use of diesel fuels. In the northern part of the state, the California Air Resources Board, the agency responsible for regulating the state's air quality, is pondering whether to declare diesel emissions a "toxic threat." In Southern California, state Attorney General Dan Lungren (who just happens to be the Republican nominee in this fall's race for governor) has joined with four environmental groups to sue area supermarkets for endangering people's health by having all that health-preserving food delivered via health-infringing diesel trucks.

These efforts in California may well serve as the prelude to a nationwide campaign: Diesel emissions are targeted by the U.S. Environmental Protection Agency, which is implementing new regulations against particulate emissions. (See "Polluted Science," August/September 1997.) And the Natural Resources Defense Council has hosted photo-ops in California and New York City, highlighting the presumed health risks of exposure to diesel fumes.

Granted, diesel emissions are noxious. Granted, too, that the small particles in the fumes are lung irritants. And granted, they are probably carcinogenic. The question is, other than scaring people half to death, what should we do about the fumes? Few pollutants are "pure risks" - that is, solely toxic and life destroying. Most are somehow bound up in the production of goods and services that provide real benefits to people. Although utopian environmentalists hate to talk about trade-offs and cost-benefit analyses, the proper regulatory framework is to consider risk in relative terms: After counting up the good, the bad, and the ugly effects of a given substance, will eliminating it cause more harm than good?

So the diesel health risk needs to be put in perspective. Though hotly - and unsurprisingly - disputed by the trucking industry, the most recent credible estimate of diesel lethality is a...