Agency Drops Science for a Wishful Finger-in-the-Wind

The Environmental Protection Agency, facing a closetful of required but unfinished homework on the risk of toxic chemicals and confronted with a lawsuit that challenges its failure to protect the public, suddenly has discovered new ways to recalculate a major chemical hazard.

Conveniently, these novel approaches to the evaluation of health risk just happen to change the numbers enough so that the EPA feels justified in not taking the protective actions that would otherwise be required by law. In 1982, this happened with the chemical formaldehyde. In 1988, it is dioxin.

In a proposed “update report” on dioxin and its health risks, the EPA has put forth a radical recalculation of the dose that is associated with a significantly increased risk of cancer. (The usual threshold of regulatory action is a one-in-a-million extra risk.) In 1985 a distinguished panel of outside scientific experts--from industry, government, academia and public interest groups--concurred with the EPA’s qualitative judgment that the key dioxin compound TCDD caused cancer, and they calculated the maximum daily exposure that should be allowed.

After the updated report, the EPA increased the allowed daily exposure 16-fold. But why the strong reaction from environmentalists and concerned scientists? After all, EPA still agrees that dioxin is the most potent synthetic chemical carcinogen ever tested.

Because in order to reach its recently updated limit, the EPA had to abandon the scientific basis for its policy on controlling cancer risks. Thus, the new risk assessment for dioxin signals more than simply a change in direction on an unusually controversial chemical. It is a return to the finger-in-the-wind, anti-scientific method of decision-making that so embarrassed EPA in the early 1980s. As such, it is a danger sign for the future of rational decision-making on other toxic hazards.

Asbestos may be next: The EPA is taking comments on its earlier health risk calculations in response to a proposal to phase out most uses of this known carcinogen. Remarkably, the agency’s retreat from science takes place despite a consensus on what should be the scientific bases for carcinogen regulation, and despite new data that strengthens the evidence of dioxin’s carcinogenic effects in humans.

The EPA claims that new scientific data supports taking another look at dioxin. That is true. Buried deep in the appendixes to the agency’s update report, there is reasonable discussion of some of these new data. But the new data disprove the need for a new calculation of risk. The new data--based on human evidence--actually confirm the old calculations of evaluating risk based on animal evidence.

In the absence of a scientific basis for radical revision, the EPA has turned to an accountant’s approach. The new calculation resulting in the 16-fold increase in allowed exposure is nothing more than an averaging of the results of various risk assessments done around the world. But scientific truth is not based on the average of right and wrong answers. Nor is it determined by a popularity-poll approach to data analysis.

The EPA’s decisions are required to be based upon sound science, and upon rational inferences from scientific principles. If the science does not support the EPA’s wishful conclusion that the risks are too small to worry about, then the agency has no excuse for evading its legal obligation to protect the public health.

What are the practical implications for all of us? First, lowering the allowable exposure to dioxin will effectively open the gates for widespread construction of municipal garbage incinerators, which emit dioxin; it will undermine effective controls on their air emissions and responsible management of their toxic ash residues. Second, the pressure to clean up some of the nation’s most notorious hazardous waste sites will be eased if the EPA can overturn the current guideline for dioxin in soil. Third, the paper industry will not have to take steps to keep dioxin contamination out of things like babies’ diapers. And fourth, and most egregiously, the EPA can continue to duck responsibility for recognizing and doing something about the fact--admitted in the appendixes to its own update report--that current exposures of the American population to dioxin, particularly through contamination of breast milk, are unacceptably high.

Don’t raise the bridge; lower the river. If we don’t want to raise the protections against human exposure, we can lower the calculated risk. That is the philosophy at work here. It is a political decision, of course. But its cloak of science is as transparent as the the emperor’s new clothes.