Seeking the Truth in Toxics : Like it or not, it’s appropriate to take another federal look at dioxin

Whatever else the chemical compound dioxin may do, it is going to haunt efforts by regulators to protect industrial societies from their byproducts for a long time.

Fused in a meeting of heat and chlorine, dioxin has for years been at the head of the list of dangerously toxic chemicals that are loose in the U. S. environment.

It got there because in the 1960s and 1970s guinea pigs died from exposure to it in a matter of weeks. It also got to the top of the danger list because techniques for determining its toxicity to humans were less sophisticated then.

Some scientists now are backing away from previous assessments. The U.N.’s World Health Organization is saying that American standards are 1,600 times tougher than necessary. The Environmental Protection Agency plans to spend a year reviewing the evidence on dioxin.

Some environmentalists are fighting back, claiming that all of the second-guessing is designed to save manufacturers the cost of cleaning up after spills and around their plants.

William K. Reilly, who heads EPA, recognizes that he is hitting a hornet’s nest with a stick and that he will be damned if he does look back and damned if he doesn’t.

In a gem of understatement, Reilly says, “There is not much precedence . . . for pulling back from a judgment of toxicity,” but that new data suggests a lower risk.

Juries have awarded millions of dollars in damages to people who made the case that dioxin ruined their health. Dioxin is blamed for causing cancer among Vietnam veterans, and birth defects in their children. It was a key ingredient of the defoliant Agent Orange, which was sprayed on forests in Southeast Asia.

One scientist who is having second thoughts is Dr. Vernon N. Houk of the federal Centers for Disease Control. He urged all 2,240 residents of Times Beach, Mo., evacuated in 1982 because its roads were contaminated with dioxin.

He says he had no choice then because his lab was producing chilling reports on dioxin. Now the data says differently. It makes no case for a wholesale review of toxics, but on the matter of dioxin Reilly has no choice, either.