Book Review: Endocrine disruption - ACS Publications - American

The ability of the human species to change the face of the Earth and the composition of the atmosphere has reached a scale comparable to that of natur...
0 downloads 0 Views 4MB Size
BOOK REVIEWS Endocrine disruption Our Stolen Future. Theo Colborn, John Peterson Myers, Dianne Dumanosk;; Dutton, New York, 1996. $24.95 (paper). Anthony D. Cortese The ability of the human species to change the face of the Earth and the composition of the atmosphere has reached a scale comparable to that of natural forces. Could the widespread use of synthetic chemicals since World War II—a major force in these alterations—also be threatening the very characteristics that make us human as well as our health and survival? Unfortunately, the answer to that question is "yes" say the authors of Our Stolen Future: Theo Colborn, a senior scientist at the World Wildlife Fund; Boston Globe science writer Dianne Dumanoski; and John Peterson Myers, a zoologist who heads the W. Alton Jones Foundation. The book's foreword by Vice President Al Gore describes it as a sequel in many respects to Rachel Carson's Silent Spring. This hard-hitting book chronicles the rapidly unfolding story of several dozen commonly used chemicals that can disrupt hormones and pose a particular problem in early development as has been observed in a wide range of vertebrates including fish birds alligators seals w h a l e s and

possiblv humans Our Stolen Future raises a clear alarm about the potential global threat posed by endocrine-disrupting chemicals. But is this another environmental scare with little scientific foundation? Are the authors right about the potential effects of ubiquitous hormone-disrupting chemicals on humans and wildlife? Is this just the tip of the iceberg given that so few chemicals have been tested for hormone-disrupting potential? The authors make an articulate and logical case for their position in the form of a detective story, which

makes the book engaging and easily accessible to a broad readership. Despite the popular style, the book is remarkably comprehensive and up to date in addressing the relevant literature and in dealing with many of the counterarguments that inevitably arise. The authors demonstrate a refreshing ability to think in complex, systemic ways about environmental and health risks that are generally handled in a piecemeal and linear fashion. And they are careful about separating the limits of knowledge from their opinions as they ask some probing and far-reaching questions

The book concentrates on Colborn's investigation of the endocrine issue as recounted by Dumanoski, the principal writer. The story begins in the late 1980s when Colborn was studying environmental health issues in the Great Lakes. Despite widespread improvements in environmental conditions, the scientific literature contained evidence of continuing problems for the lakes' wildlife. Many species still carried a host of persistent chemicals (e.g., DDT, dioxins) and seemed to show signs of ill health, including reproductive problems abnormal behavior and impaired immune systems

crine system, which regulates the body's vital internal processes and guides those critical to prenatal development. Driven by the question of whether such contamination was jeopardizing humans as well, Colborn combed the literature and talked with a wide range of scientists. From the tragic experience with the drug Diethylstylbestrol (DES), a synthetic estrogen given to millions of women in the mistaken belief that it would prevent miscarriages, she learned that humans appeared vulnerable to hormonal disruption caused by synthetic chemicals and that such disruption before birth COu.ld ca.u.SG invisible damage such and deformed reproductive tracts that might not become evident until a child reached adulthood Laboratory studies done with also provided evidenrp that synthetic hormone caused the same kind of damage in humans and animals Then Colborn discovered studies showing that some pesticides and industrial chemicals could act similarly to DES by mimicking natural estrogen. As research into the endocrine-disrupting chemicals proceeded, scientists have discovered at least 50 compounds that can interfere with natural hormones such as estrogen, testosterone, and thyroid hormone by mimicking, blocking or disrupting in other ways. The chemicals include certain chlorinated organic pesticides; phthalates used in paints and inks; and alkyl phenols which are products of the breakdown of some detergents herbicides and cosmetics

Colborn found a pattern of problems concentrated among the fisheating predators at the top of the food chain that seemed to affect offspring rather than adult animals. Moreover, most of the problems seemed to be linked to disrupted development. As she dug deeper into the peer-reviewed studies, Colborn discovered that the most common contaminants in Great Lakes wildlife could all act on the endo-

Colborn's concern escalated when she learned that a single low dose of dioxin (at a level in the range found in humans) to a pregnant rat caused reduced sperm count and other long-term damage to the reproductive system in offspring. In July 1991, Colborn and Myers assembled 21 researchers in Racine, Wise, who issued a warning that hormonedisrupting chemicals threaten the survival of animal populations and

The emergence of endocrine disruptors creates fundamental scientific and policy challenges.

0013-936X/96/0930-213AS12.00/0 © 1996 American Chemical Society

VOL. 30, NO. 5, 1996 / ENVIRONMENTAL SCIENCE & TECHNOLOGY/ NEWS • 2 1 3 A

STAY AHEAD OF THECURVE Must Reading for Fast Track

Professionals

Who reads Industrial & Engineering Chemistry Research? Leading chemical engineers and industrial chemists worldwide. Each month Industrial & Engineering Chemistry Research delivers up-to-the-minute original studies and reports in the area of kinetics and catalysis, materials and interfaces, process engineering and design and separations. Peer-reviewed, quality information on the fundamental and theoretical aspects of chemical engineering, process design and development, and product R&D. And I S. EC Research satisfies your need for in-depth knowledge with special sections or entire issues devoted to selected topics, including current research notes, correspondence, and reviews. Look to I & EC Research for vital information you need to stay ahead of the curve, and push into new frontiers. Timely. Practical. Reliable. Comprehensive. "Aggressive... innovative... indispensible" are how leading industrial and chemical engineers around the globe describe I & EC Research. Don't miss a single issue. Call now!

Call Toll-Free 1-800-333-9511 in the U.S. Outside the U.S.: 614-447-3776. Fax: 614-447-3671. Or Write: American Chemical Society Member and Subscriber Services P.O. Box 3337 • Columbus, OH 4 3 2 1 0 1 9 9 6 Subscription Rates Canada & U.S. Mexico ACS Members One Year $ 7 0 $ 94 Two Years $ 126 $ 174 IMonmembers One Year

Published by the American Chemical Society under the editorial leadership of Donald R. Paul, University of Texas, Austin.

$ 834

Europe*

All Other Countries*

$ 129 $ 244

$ 144 $ 274

$ 893

$ 908

$ 858

* Air Service Included.

American Chemical Society 1155 Sixteenth Street, N.W. Washington, D.C. 20036 ACS

PUBLICATIONS s ™ « A™*™ /»- ;*-- ««M S *J JV™™

Member subscription rates are for personal use only. Subscriptions are based on a calendar year. Foreign payment must be made in U.S. currency by international money order, UNESCO coupons, or U.S. bank draft, or order through your subscription agency. For nanmember rates in Japan, contact Maruzen Co., Ltd. This publication is available on microfilm and microfiche. The full text is available online on STN International.

2 1 4 A • VOL. 30, NO. 5, 1996 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS

jeopardize the human future. A chapter titled "Altered Destinies" examines whether humans exposed to hormonally active chemicals are showing evidence of the reproductive and behavioral effects seen in wildlife and laboratory animals exposed to such chemicals and in humans exposed to DES. They cite evidence of problems in many areas, including rising rates of hormonally related cancers, increased genital defects, and various reports that male sperm counts dropped by 50% between 1938 and 1991. Although acknowledging that there is uncertainty about the scope of the problem, the authors believe that the parallel evidence in laboratory studies, wildlife, and the DES experience makes a strong case for concern about human and environmental health problems from hormonally active chemicals. The authors make a number of recommendations about research needs and directions, actions the public can take to reduce BXDOSUX6 t o hormone disruptors, and public policy and industry initiatives The research and public policy suggestions are sound and the most comprehensive with an emphasis on assessment of effects and prevention of exposure from individual as well as groups of compounds The emergence of endocrine disruptors creates some fundamental scientific and policy challenges. It challenges the assumptions about toxicity and disease that have been the basis for risk assessment for the past three decades. Endocrine disruptors are not classic poisons—they do not cause cell death or DNA damage, and many are not carcinogenic. If there is one prescriptive message the authors want to coUVGV it is that we must get beyond the toxicity- = Q^fjcer paradigm. These chemicals also defy the current dose-response notions that higher doses inevitably cause more damage. In recent studies of lowdose exposure to DES in animals that show similar effects to those of human DES users, researchers found that the response increases with dose for a time and then begins to diminish, looking like an inverted U, presumably because of some protective mechanisms at higher doses. Rather than overestimating risk as has sometimes been the case with cancer-causing chemicals extrapolating from high to low dose may seriously underestimate health risks

There are other difficulties in risk assessment. The doses that cause hormone disruption can be extremely low (parts-per-trillion levels), making detection difficult except with sophisticated and expensive equipment. Laboratory studies indicate hormonal effects in mixtures of tiny doses of chemicals where none occur from the individual chemicals. There are no synthetic chemical-free humans for epidemiological comparison. And intergenerational exposure information is almost impossible to find There is cin urgent need for new research on risk assessment techniques and on the exposure (e 2 from food Dackaging) and effects of hormonallv active chemicals

A sustainable society must reduce its dependence on persistent unnatural substances. Although the magnitude of the threat to human health and the environment is unclear, it would be imprudent to underestimate its seriousness, retreat into denial, or wait until the effects are overwhelmingly demonstrated. If there is one thing we have learned in the past 50 years in dealing with environmental problems it is that there may be nasty surprises that show up decades later because we cannot ever have sufficient knowledge to predict long-term effects in the highly complex natural world including our own bodies Simplistic efforts such as the outright ban of a single chemical or discovery of substitutes will not work in the long run. DDT and CFCs, which were at the time they were invented the safest substances for their use, decades later are undermining the Earths life support system. Some of the persistent synthetic hormone disruptors will remain in the environment for decades or centuries. The authors point out that there is no way to put large quantities of synthetic substances into the environment without exposing ourselves a.nd our children to unknown risks And with exponential growth in population and economic activity compoundint? the problem we will al-

ways be "flying blind." Most of the 70,000 chemicals in commerce have not been tested for potential health or environmental effects. The presumption is that they are innocent until proven guilty by the government or the public. From a public policy standpoint, the burden of proof of chemical safety should be shifted to chemical manufacturers. This is the most prudent way to reduce environmental and health risk and long-term economic risk because of the regulatory liability worker consumer and investor pressure that inevitably will result Because basic scientific laws of conservation of matter and entropy tell us that nothing disappears and everything disperses, a healthy and sustainable society must reduce its dependence on persistent unnatural substances. This means designing an economy that mimics and lives within natural systems in which there is no waste. Moving from a linear to a more natural, cyclic economy will require strategies such as sustainable agriculture and closed-loop manufacturing and changes in the design of chemicals cind jYi^tericils so they not harmful and easily be disassembled and reconstituted There is increasing evidence of the viability of such strategies. Interface, the world's largest commercial carpet manufacturer, leases (not sells) flooring that is nontoxic and is taken back when worn out and reconstituted into new flooring. The big three automakers are designing a car for nearly complete disassembly and recyclability. Movement of the economy in this direction will require long-term shifts in economic and regulatory incentives as well as a paradigm shift toward the ecological perspective in education. Our Stolen Future will have done society a great service if it motivates us to move in this direction. It should be read by all scientists, policy makers, business people, and other professionals involved in the heart of our industrial economy. Anthony D. Cortese is CEO o/Second Nature, a nonprofit organization that promotes human and environmental well-being through learning, and founding director of The Natural Step US. He is the former dean of environmental programs at Tufts University and commissioner of the Massachusetts Department of Environmental Protection.

Must Reading! The Internet: A Guide for Chemists

This timely book presents the basics of the Internet along with instructions on becoming an information provider on the Internet. In a stepwise and thorough manner it describes how to use the major Internet resources, including e-mail, electronic lists, Gopher, FTP, and the World Wide Web and gives useful information specific for chemists, such as Web addresses, electronic mailing lists, Gopher sites, and FTP sites. Also includes a brief history and overview of the Internet and describes how a chemical company has integrated the Internet into its business regimen Contents History of the Internet Electronic Mail The Berkeley Mail Program Electronic Lists Gopher The World Wide Web Designing an Internet-Acces.sible Database Electronic Conferencing Electronic Lists for Chemists Managing the Computational Chemistry List Chemistry and Gopher Gnemistry and the World Wide Web Steven M. Bachrach, Editor, N o r t h e r n Illinois University S60 pages(1996) Clothbound: ISBN 0-8412-3223-7, $29.95 (plus $3.00 handling) Paperbound: ISBN 0-8412-3224-:), $23.95 (plus S3.00 handling) ORDER F R O M A m e r i c a n Chemical Society 1155 Sixteenth Street, N W W a s h i n g t o n , DC 2 0 0 3 6 Or CALL TOLL FREE 1-800-227-5558 (in W a s h i n g t o n , DC 872-4363) and use your credit card! FAX: 2 0 2 - 8 7 2 6 0 6 7 . ACS Publications Catalog n o w available o n Internet: g o p h e r a c s i n f o . a c s . o r g or URL: h t t p : / / p u b s . a c s . o r g

VOL. 30, NO. 5, 1996 /ENVIRONMENTAL SCIENCE & TECHNOLOGY/ NEWS 1 2 1 5 A