BOOKS
Hormone Mimics In The Environment Reviewed by William R. Moomaw prepublication announcement called "Our Stolen Future" the t second "Silent Spring." Its publishers see it as a wake-up call to a new set of environmental and health problems associated with the ubiquitous use of chemicals. A quick review of Rachel Carson's 1962 classic confirms that there are, indeed, parallels between these books. But there are also some important differences. Like Carson, the authors of "Our Stolen Future" are from outside the scientific mainstream. Theo Colborn, who constructed the book's basic hypothesis, is a zoologist and senior scientist at the World Wildlife Fund. She was assisted in her analysis by John Peterson Myers, a biologist who directs the W. Alton Jones Foundation, a private foundation in Charlottesville, Va., concerned with protecting the global environment and which provided financial support for the project. Most of the actual writing was done by Dianne Dumanoski, an awardwinning environmental journalist. Together they have written a book addressed to the public and policymakers, rather than a scientific treatise for a technical audience. The individual pieces of research they have assembled come from field-specific peerreviewed literature and are carefully documented in extensive endnotes. However, the links they propose between these research findings and the overall hypothesis they present have received relatively little attention from the scientific community. That hypothesis, in a nutshell, is that low concentrations of chemicals now widespread in the environment can cause endocrine disruption, especially during fetal development. As a chemist, I come to endocrinology as a layperson, and find the chapter on chemical messengers to be highly informative (and, according to medical colleagues, accurate). The authors skillfully make their case by explaining how hormones transmit information that is used during embryogenesis to create the brain, reproductive system,
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like "Silent Spring/' new book synthesizes work from many fields to see a major environmental problem that chemists need to take seriously "Our Stolen Future: Are We Threatening our Fertility, Intelligence, and Survival? A Scientific Detective Story/' by Theo Colborn, Dianne Dumanoski, and John Peterson Myers, Dutton, 375 Hudson St., New York, N.Y. 10014,1996,306 pages, ISBN 0-525-93982-2, $24.95
and other organs. In adulthood, these hormones determine reproduction and other critical functions. Carcinogens are often species-specific metabolites of ingested chemicals; by contrast, many species share common molecular hormones. Hence, the authors argue that animal models are more likely to be relevant to humans in the study of hormonal effects. They then recount a
series of observations of birds, reptiles, fish, and other wildlife; studies on laboratory animals; in vitro research; and human epidemiology and medical cases to identify a range of anomalies that they link to synthetic chemicals acting as "endocrine mimics." Much of the book's power comes from its emphasis on alterations in sexual differentiation and reproductive outcomes. The authors describe reports of ambivalent genders of birds and wildlife; loss or diminution of primary and secondary sex characteristics, including small and deformed genitalia, undescended testes, and hermaphroditism in animals and humans; reductions in reproductive success of many animal species and infertility and declining sperm counts in human males; a rise in estrogen-stimulated cancers of the breast and prostate; and lowered intelligence and behavioral disorders in children of women exposed to certain chemicals. It is pretty scary stuff. The authors are careful to admit that, at present, much of the evidence is simply correlative, such as the relationship between high doses of polychlorinated biphenyls (PCBs) in mother's milk and behavioral problems in their offspring. Other data seem more solid—and therefore compelling—such as the reproductive problems found in the daughters and sons of women who were given the artificial hormone diethylstilbestrol (DES) during pregnancy, the estrogen-like proliferation response of breast cells to alkyl phenols leached from "inert" plastic labware, or the common set of reproductive and other developmental anomalies found in a wide variety of birds and wildlife. The authors raise an ominous note of concern over the possibility that plastic food wraps might be exposing humans to biologically significant doses of estrogen mimics. Not all of the work is new. The ability of a single dose of DDT to prevent sexual maturity in roosters was reported in 1950 and duly noted by Carson. One of the most important issues this book raises is the need for large-scale synthesis of information buried in sepa-
rate scientific specialties. That was the great contribution of "Silent Spring," and it's an important message of this book, as well. To a chemist such as my self, steeped in the relationship between molecular structure and chemical prop erties, if s hard to imagine the complex dynamic that can allow such structurally different compounds as estradiol (the natural estrogen in humans and virtual ly all other animals) and DES or PCBs to bind to the same endocrine receptor to produce similar biological effects. How can any specialist know about re search as diverse as clinical studies on DES, the declining fertility of eagles and beluga whales, lower sperm counts in humans, and the finding of estrogenic properties in industrial chemicals through laboratory assays? Colborn deserves great credit for seeking out experts in many different fields and, like Carson, reading vast numbers of research papers and re ports to create this synthesis. The book shows clearly how scientists and the agencies that fund them become captives of existing paradigms. One ex ample is the imbalance between the amount of money spent to find "cancer genes," about which we can do little, and the low level of support to study the sources and mechanisms of cancers caused by diet and agents in the envi ronment. Most of the regulatory debate of the past 20 years has been shaped by the powerful intellectual idea that chem ically induced alterations to DNA can cause mutations, birth defects, and can cer. Consequently, that is where most of the research effort has gone. But if the authors of "Our Stolen Future" have in terpreted the evidence they present cor rectly, dioxins are more likely to be dan gerous because of their effects on the en docrine system than on DNA. It's clear from the wide array of re search cited in "Our Stolen Future" that we need to continue to support disciplinary-specific research. But would it be too much to ask that a small part of the national research bud get be spent in support of attempts to synthesize and integrate findings from individual fields? Some readers will find the repetition of specific examples in "Our Stolen Fu ture" to be unnecessarily heavy-handed. I found the chapter on bioconcentration and how chemicals move in the environ ment too long. This fictionalized account of how PCBs might move from a trans former plant in Massachusetts to polar
bears in the Arctic is plausible, but te likely to be ignored even though much dious. Both Carson's Tule Lake example research still needs to be done. Undoubt of bioconcentration and Aldo Leopold's edly the book has already played a role "Odyssey" on molecular environmental in the decision to convene a panel of the transport make the point better. The National Academy of Sciences to con chapter on how to avoid exposure to duct a two-year evaluation of endocrine synthetic chemicals may provide com disrupters. The American Chemical So fort to a worried public, but it seems less ciety, recognizing both chemistry's pow convincing than much of the rest of the er to contribute to the debate and its lim book, and it detracts from the basic mes itations, should form joint task forces sage. But dismissing the book because of with appropriate biological, toxicologithese shortcomings or because one sees cal, and medical societies to evaluate re it as an attack on chemicals will only un search findings and recommend new dermine public confidence in chemists avenues of investigation. and the chemical industry. Increasing government support to test Both the public and the chemical in the validity of the proposed links will dustry have moved a long way since challenge the traditional, discipline"Silent Spring" was published in 1962. based funding structures at agencies like At that time the response of a defensive the National Science Foundation and the industrial community was denial, and National Institutes of Health. Perhaps even Chemical & Engineering News joinedthe chemical industry might create a in by titling its review of the book "Si fund to support independent, peerreviewed hypothesis testing, much as it lence, Miss Carson." The chemical industry of today is far did for the ozone depletion issue. At the more responsive and responsible. The very least, we should demand a struc days are past of dumping Kepone into tured, open debate on the scientific mer the James River, casually spreading its of the proposal that involves both the millions of pounds per year of persis public and the scientific community. To tent pesticides and chlorofluorocarbons do otherwise will jeopardize not only into the environment, or assuming that the credibility of chemists but also the a Bhopal accident was not possible. public's tolerance of the chemical indus With successful industry-sponsored try and its products. programs like Responsible Care, pri Physical chemist William R. Moomaw is vate-sector initiatives like ISO 14000, a professor of international environmental pledges such as the Business Charter policy at the Fletcher School of haw & Di for Sustainable Development, and gen plomacy at Tufts University. For 12 years, eral compliance with the Environmen until 1992, he chaired the ACS Task Force tal Protection Agency's Toxics Release on Biotechnology & the Toxic Substances Inventory, it's hard to imagine a return Control Act. Π to industry's reflexive lashing out against "Silent Spring." As the authors of "Our Stolen Fu Ion Exchange Technology: Advances in Pollution Control. Arup K. Gengupta, ture" make clear, there are many gaps editor. 399 pages. Technomic Publishing in the proposed links between very low Co., 851 New Holland Ave., Box 3535, levels of chemicals and the endocrineLancaster, Pa. 17604.1995. $89. related anatomical and behavioral anomalies that are observed. Yet the Laser Techniques in Chemistry. Vol. 23: extensive environmental distribution of Techniques of Chemistry. Anne B. Myers, Thomas R. Rizzo, editors, xii + synthetic chemicals and the demon 429 pages. John Wiley & Sons, 605 strated impact of exposure to minus Third Ave., New York, N.Y. 10158cule doses of endocrine mimics at criti 0012. 1995. $125. cal times during fetal development re quire a credible response. Lithium Chemistry: A Theoretical and Although some aspects of the book Experimental Overview. Anne-Marie will undoubtedly be annoying to many Sapse, Paul von Ragué Schleyer, editors, χ + 595 pages. John Wiley & Sons, chemists, ignoring or dismissing its mes 605 Third Ave., New York, N.Y. 10158sage would be a serious mistake. Nei 0012. 1995. $69.95. ther the public nor political leaders are likely to ignore an issue as critical as an Masters in the Pure and Applied Sciences. alleged threat to the reproductive future Vol. 38. Wade H. Shafer, editor, xiv + 413 of our own species. "Our Stolen Future" pages. Plenum Press, 233 Spring St., New raises important questions that are un York, N.Y. 10013.1995. $149.50. Q APRIL 1,1996 C&EN 35
