Commentary: Junk Science And Mass Hysteria

The announcement that England's mad cow disease was implicated in 10 cases of a fatal human brain disorder has been met with understandable hysteria. The market for British beef collapsed, 100,000 farmers' jobs are in jeopardy, and the government is scrambling to defuse a crisis that could cause billions of dollars in losses.

But what is striking about the situation is how starkly the decisive public reaction to the crisis contrasts with the cautious language in the announcement. Scientists said consumption of tainted beef was "the most likely explanation" for 10 cases of a similar human illness called Creutzfeldt-Jakob disease--nothing more definite than that.

HAIR TRIGGER. The crisis is a telling example of a phenomenon occurring ever more frequently: A complex scientific debate is suddenly thrust upon an anxious public that is ill-equipped to understand it. Instant and ubiquitous communications, combined with the greater willingness of plaintiffs and government and industry leaders to go public with their scientific disputes, trigger concern. The core of real science gets overwhelmed by a flurry of "junk science"--conflicting statements by politicians, confusing press reports, legal depositions, even dueling ads.

The U.S. has its own examples. In recent weeks, Americans have watched in confusion as the makers of Tylenol and Advil wage a scorched-earth campaign in newspaper and TV ads over the safety of Tylenol when combined with alcohol. The manufacturer of Tylenol acknowledges that there is risk with high intake of both Tylenol and alcohol. But is there a risk for the casual drinker? Advil's advertising is forcing that question on consumers, when scientists themselves can't answer it. And Advil, too, has side effects--like aspirin, it can raise the risk of stomach bleeding.

Another case: the long-running dispute over the safety of silicone breast implants. In February, the largest study yet of the possible risks of such implants gave comfort to both sides in the dispute. Plaintiffs suing implant makers pointed to the study's finding of some risk; defendants emphasized that the risk was very small. The uncertainty remains.

In each of these controversies, a core of solid scientific information falls short of what's needed to resolve urgent questions facing the public. The economic and health consequences are enormous. With the stakes so high, powerful forces in government and industry are eager to shape the disputes. "This is tremendously difficult for the public to sort out. If scientists are disagreeing, what's the citizen to presume?" asks Paul Slovic, a psychologist at Decision Research in Eugene, Ore.

The real problem is the nature of scientific inquiry, which inevitably involves uncertainty. Researchers cannot say conclusively whether mad cow disease poses a risk to humans. They don't know the extent of the epidemic or how it can be stopped. Indeed, they can't even agree on the cause. The leading theory, advanced by Stanley B. Prusiner of the University of California at San Francisco, is that both the human and cattle diseases are caused by an unusual biological entity called a prion--a tiny scrap of protein without genes or any of the biochemical machinery bacteria and viruses require to do damage.

MANY DOUBTS. Prions act slowly, causing symptoms years or even decades after the infection is contracted. Mad cow disease isn't known in the U.S., but doubts arise again: Scientists can't be certain it isn't there. Other experts, such as Laura Manuelidis of Yale University, don't accept the prion theory. She thinks yet-to-be-identified, slow-acting viruses are responsible.

One lesson to be drawn from these public disputes is that governments shouldn't cut funding for basic research, which can help prevent tomorrow's crises. But the only real solution is for government and industry leaders to use scientific information responsibly. No more spectacles like the one last year when Britain's agriculture minister sought to reassure the public by feeding his 4-year-old daughter beef in front of television cameras. Unresolved scientific disputes have become a fact of modern life. Nothing else so clearly illustrates science's limits.

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