Keeping Cool About Risk

By J. MADELEINE NASH

Alar on apples, radon in homes, asbestos in schools. the U.S. appears to ricochet from one environmental crisis to another, with the result that policy aimed at reducing risks to human health frequently appears to make little economic or scientific sense. Even some environmentalists concur that decisions to rip asbestos out of school buildings were probably ill considered. In many cases, sealing the dangerous fibers in place would have provided a more prudent and less costly remedy. Similarly, while no one denies that homes with high levels of radon pose a health hazard requiring prompt attention, what about houses with much lower levels? Is it reasonable to urge that they too be radonproofed if there is no certainty that a danger exists?

Now environmentalists say dioxin and scores of other chemicals pose a threat to human fertility -- as scary an issue as any policymakers have faced. But in the absence of conclusive evidence, what are policymakers to do? What measures can they take to handle a problem whose magnitude is unknown?

Predictably, attempts to whipsaw public opinion have already begun. Corporate lobbyists urge that action be put on hold until science resolves the unanswered questions. Environmentalists argue that evidence for harm is too strong to permit delay. The issue is especially tough because the chemicals under scrutiny are found almost everywhere.Since many of them contain chlorine or are by-products of processes involving chlorine compounds, the environmental group Greenpeace has demanded a ban on all industrial uses of chlorine. The proposal seems appealingly simple, but it would be economically wrenching for companies and consumers alike.

With the escalating rhetoric, many professionals in the risk-assessment business are worried that once again emotion rather than common sense will drive the political process. "There is no free lunch," observes Tammy Tengs, a public-health specialist at Duke University. "When someone spends money in one place, that money is not available to spend on other things." She and her colleagues have calculated that tuberculosis treatment can extend a person's life by a year for less than $10,000 -- surely a reasonable price tag. By contrast, extending a life by a year through asbestos removal costs nearly $2 million, since relatively few people would die if the asbestos were left in place. That kind of benefit-risk analysis all too rarely informs the decisions made by government regulators.

As the EPA raises anew the dangers of dioxin, the agency needs to communicate its findings to the public in a calm and clear fashion. No one is eager to touch off the kind of hysteria that preceded the government's decision to move against Alar, the growth regulator once used by apple growers. When celebrities like Meryl Streep spoke out against Alar and the press fanned public fears, some schools and parents rushed to pluck apples out of the mouths of children. Yet all this happened before scientists had reached any consensus about Alar's dangers.

Rhetoric about dioxin may push the same kind of emotional buttons. The chemical becomes relatively concentrated in fat-rich foods -- including human breast milk. Scientists estimate that a substantial fraction of an individual's lifetime burden of dioxin -- as much as 12% -- is accumulated during the first year of life. Nonetheless, the benefits of breast-feeding infants, the EPA and most everyone else would agree, far outweigh the hazards.

John Graham, director of the Harvard Center for Risk Analysis, suggests that people should strive to keep the perils posed by dioxin in perspective and remember other threats that are more easily averted. "Phantom risks and real risks compete not only for our resources but also for our attention," Graham observes. "It's a shame when a mother worries about toxic chemicals, and yet her kids are running around unvaccinated and without bicycle helmets."