From Silent Spring To Barren Spring?

A new book says pesticides may threaten human reproduction

After a pesticide accidentally spilled into Florida's Lake Apopka, alligators were born with half-size penises. In the laboratory, rats given DDT developed striking abnormalities of their genitalia. Male fish and birds exposed to pesticides in the Great Lakes became unable to reproduce.

These disquieting findings are the subject of a controversial new book that could become the biggest scientific and public-relations bombshell to hit the chemical industry since Rachel L. Carson's 1962 classic, Silent Spring. In Our Stolen Future: How We Are Threatening Our Fertility, Intelligence & Survival--a Scientific Detective Story, authors Theo Colborn of the World Wildlife Fund, Dianne Dumanoski of The Boston Globe, and John Peterson Myers of the W. Alton Jones Foundation for the first time summarize the potential dangers of "endocrine disrupters," chemicals that interfere with reproductive hormones. The book is backed by some heavy hitters: Vice-President Al Gore wrote the preface; environmental flack David Fenton, who in 1989 stirred up a frenzy over the use of Alar on apples, is handling its PR.

Behind Our Stolen Future is the growing realization that DDT, PCBs, dioxin, and hundreds of other chemicals can mimic estrogen and testosterone. In so doing, they can disrupt the endocrine system, which regulates reproduction.

The big question is whether the chemicals in question are causing disturbing reproductive problems now being seen in humans: an apparent drop of as much as 50% in sperm counts during the past few decades, a 30% rise in breast cancer (partly due to better diagnosis), and in some areas a tripling in the rates of testicular cancer. The book's authors say the evidence is growing that pesticides play a role in the increases. "Some of the human epidemiologic research that's coming out would suggest that we are at levels right now where we could expect effects," says Colborn.

The scientific community is heeding the warning. The Environmental Protection Agency has expanded research on endocrine disrupters, fearing they could become "a very serious problem," says Robert J. Huggett, the head of EPA's research office. Before he joined the EPA, Huggett, a marine chemist, studied an antifouling agent for ships' hulls--tributyl tin--which has dramatic side effects. "It changed the sex of some species of oysters and changed the whole shape of the oyster," he says.

DISPUTED DATA. Also worrisome is the chemicals' multiplier effect, says Lawrence W. Reiter, director of an EPA laboratory in Research Triangle Park, N.C. "The body is exquisitely sensitive to these hormones," he says. "If you have an environmental chemical which interferes with those hormones at very small levels of exposure, the possibility of producing adverse effects is amplified."

Aware of the concerns, the Chemical Industry Institute of Toxicology, a company-backed research group, has moved 10% of its research budget into the study of endocrine disrupters. "There is sufficient information, albeit some of it fairly weak, that does warrant detailed and rigorous investigation," says Paul Foster, the institute's director of endocrine toxicology.

Still, the industry worries that the media will exaggerate the risks. The Chemical Manufacturers Assn. has prepared a point-by-point rebuttal of what it says are uncertainties and errors in Our Stolen Future. "We view this book as raising a theory," says CMA official Sandra Tirey. "There appears to be a fair amount of disagreement in the scientific community about the interpretation of the data."

Researchers say it will take three to five years to assess the magnitude of the threat. If the risk is confirmed, the chemical industry could face a serious challenge. "This is raising an issue that is likely to stir up the public," says Reiter. "It has some fundamental implications in terms of reproduction and development. That strikes home with a lot of people."

In Silent Spring, Carson worried about the disappearance of birds. Now the issue is the possible disappearance of our own unconceived offspring and the fear that the latest endangered species could be us.

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