FEATURE
Will Our Stolen Future Be Another Silent Spring? A new book sparks debate over endocrine disruptors and the regulation of synthetic chemicals and pesticides. JEFF
S
JOHNSON
ynthetic chemicals' potency to influence endocrine systems vaulted into the spotlight last month with the publication of Our Stolen Future (i) by scientists Theo Colborn and John Peterson Myers and science journalist Dianne Dumanoski. Like Rachel Carson's groundbreaking Silent Spring (2), to which it is being compared, the 300-page book raises the specter of a world awash in synthetic organic chemicals, many with the power to mimic natural hormones and upset normal development in wildlife and humans. The authors chronicle 30plus years of health research and present a dramatic call to action based on that evidence: hormonally active chemicals posing the greatest risk should be forced off the market. The authors argue that synthetic chemicals should be assumed guilty until proven innocent. They urge that negotiations begin for both a worldwide phase-out of production and use of persistent hormonedisrupting chemicals and that new financial support be provided for the containment, retrieval, and cleanup of the chemicals. Our Stolen Future is expected to heat up an ongoing debate over regulation and testing of synthetic chemicals and focus attention on the significance of the health issues it presents. Even before the book was released March 18, the debate was joined by public officials and industry. In February, the book was pulled from the presses
so that an introduction by Vice President Al Gore could be added, and a few weeks before release officials with the Chlorine Chemistry Council (CCC) announced an inaustry-runaea scientific symposium on endocrine disruptors, organized by Clemson University. A symposium report was planned to be issued at its conclusion, CCC officials said, to coincide with the book's release. Recent articles in Esquire (3), The New Yorker (4), and Natural History (5) also heralded the book. The first two focused on studies by Danish and French scientists showing a 50% decline in human sperm count over me last 50 years. "A minefield" is how an iPA official described discussions with chemical industry representatives about attempts to limit the use of endocrine-disrupting chemicals. Emerging research concerns Our Stolen Future identifies a growing number of studies showing reproductive abnormalities and some cancers in wildlife and humans, as well as suggesting disabilities in learning, behavioral, and immune systems. The blame, the authors say, lies with some 50 synthetic chemical compounds that the body confuses with endogenous hormones. The synthetic hormonal mimics have the power to trigger developmental abnormalities or block normal development. The effects are thought to be transgenerational: hormonal changes in the mother are reflected in the development of the fetus but may not be discovered until later in life.
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The book attempts to synthesize decades of anentific understanding of the threat these comecdotal information and peer-reviewed studies that pounds pose to humans. But the authors urge peoimplicate synthetic chemical compounds as potent ple to take personal preventive actions: test drinking environmental hormones that, in most cases, mimic water and select food carefully, for instance. They also estrogen but may also block androgen receptors. The call for institutional changes, such as further health authors use chemistry, molecular biology, and reresearch and tougher government testing policies and ceptor theory to explain what lies behind a growing regulations that consider the potential of endochorus of scientists who have discovered classes of crine disruption in pesticides and chemicals before synthetic chemicals that upset the complex horthey are released to the environment or used in promonal ebb and flow. duction. Specifically, they urge: Studies profiled in the book include Niels Skak• consideration of cumulative exposure and inkebaek's work on sperm counts and testicular canteraction of different chemicals, media, and sources cer in Danish men, Louis Guillette's study of Lake Apwhen setting exposure standards; opka, Fla., alligators exposed to high levels of the • shifting to industry the burden of showing a pesticide dicofol, studies of reproductive abnormalichemical to be safe and requiring a demonstration ties in humans and rats resulting from exposure to DES before the chemical is used; (diethylstilbestrol), and the discovery by Ana Soto and • amending trade secret laws to make it easier for Carlos Sonnenschein that alkylphenols used in plasthe public to know what is in chemical products; and tics break down to nonylphenols, an estrogen mimic. • reducing the numbers of chemicals in commerce to simplify testing and regulation. The book is in part a narrative mystery with Colborn as sleuth, gathering scientific evidence that But some in the scientific community question seems to arrive at her door with disturbing regularwhether the accumulated evidence justifies prevenity. Through the chapters, evidence accumulates: detive action. "In a way, this isn't a scientific issue at clines in quality and quantity of human sperm, reall," says James Lamb, a reproductive and developproductive abnormalities, "lesbian seagulls," seal and mental toxicologist and dolphin die-offs, smaller penises in wildlife and man, industry consultant who a growing incidence of breast and testicular cancer, has worked at EPA and the The authors argue and high levels of synthetic chemicals in the tissue National Institute of Enof affected species. vironmental Health Scisynthetic chemicals ences. He charges that the The authors' concern about the unintended efauthors are "confusing hyfect of synthetic chemicals is illustrated in an early should be assumed pothesis with knowledge." chapter on DES, the widely prescribed "wonder drug" In particular, he says the that was incorrectly thought to stop miscarriages a guilty until proven claims of declining sperm generation ago. DES is now a well-studied estrogen counts in humans are innocent. mimic and one that even skeptics accept. DES was contradicted by other found to bind with receptors in the mother's cells, studies showing no deturning on and off actions that affect the fetus durcline. He acknowledges that a French study showing key times in its development. Timing was found ing dropping sperm counts was well structured and to be everything here, the authors say, and it may accurate, but he says another study of Finnish men matter more than dose. For daughters whose mothers took DES during turned up normal sperm levels. pregnancy, reproductive tract abnormalities and Lamb conjectures that these differing results may cancers did not develop in cases when the mother be the result of lifestyle or a host of other atbegan taking DES after hormones that trigger the tributes, rather than chemical exposure. He also says tract's formation within the fetus had already it is unclear exactly to what chemicals the men in acted, the authors note. The trigger is a delicate balthese studies were exposed. Further research is warance of timing and dose. Without the right horranted, he says, and it should be prospective, based monal cue at the right time, the fetus will not deon new data. He warns of the possibility of "endvelop correctly. less collection" of data, because of the transgenerational nature of the problem and the huge numEnvironmental estrogens include DDT and other ber of variables, but adds that information will organochlorine pesticides, dioxins, polychlorinated accumulate as the studies progress. biphenyls (PCBs), alkylphenol polyethoxylates, several fungicides and herbicides, and an array of inLamb and others note the growing interest in this dustrial chemicals. Complicating research, horarea of research. For instance, a committee of the Namonal disruption can come from compounds with tional Research Council, of which he is a member, different structures, the authors say, as well as "safe" has been formed to review the issue, and a report is compounds that degrade into disruptors. For inexpected within two years. stance, some plastics, personal care products, conEPA has also developed a research strategy for entraceptive creams, detergents, and pesticides have docrine disruptors and has set aside some $5 milbeen found to break down during normal use into lion for extramural endocrine research this year as nonylphenol, another estrogen mimic. well as a smaller internal research program (ES&T, Nov. 1995, 494A). The National Institute of Environmental Health A call to action Sciences has had a research emphasis in this area The most concrete and obvious problems have shown since the mid-1970s, officials say, and will fund about up in wildlife, and the authors acknowledge that $3.3 million this year in extramural grants. "many unknowns and uncertainties" remain in sciVOL. 30, NO. 4, 1996 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS • 1 6 9 A
"A passing interest"? The call for more research was also voiced by Roger McClellan, head of the Chemical Industry Institute of Toxicology (CUT). However, McClellan notes, "You really can't say today whether this is a very important issue or one of just passing interest." McClellan even questions using the term "disrupter" until scientists get better insight into potency. He prefers "endocrine modulation" because the chemicals appear to have a wide variance in their ability to influence endocrine systems. CUT has received so many requests for information on this subject, McClellan says, that it has prepared a packet explaining the issue and laying out the institute's endocrine research agenda. Under a new contract from the CCC and the Chemical Manufacturers Association, CUT has formed an endocrine toxicology program, hired a program director last December, and plans this year to spend 10% of its $16 million budget on endocrine-related research. In the past, CUT has done little research in the endocrine area, McClellan adds. A few weeks before the book's release, the CCC announced a symposium, "Process and Principles for Evaluating Endocrine Disrupters in Wildlife," bringing together researchers from industry, academia, and government. Organized by Clemson University's Institute of Wildlife and Environmental Toxicology, the March symposium is expected to generate a plethora of scientific papers, according to Ron Kendall, conference chair and director of the institute.
Echoes of Silent Spring Our Stolen Future has been compared to Silent Spring in its portrayal of the danger posed by widespread and unchecked chemical use. The authors echo Rachael Carson in laying much of the blame at the door of the chemical and pesticide industries. U.S. production of organic synthetic chemicals topped 435 billion pounds in 1992, they report, more than 1600 pounds per person. Carson also warned against indiscriminate chemical use, especially of organic, carbon-based compounds with the ability to actively modify life forms. While life has evolved along with natural estrogens, she argued, species have had no time to make evolutionary adaptations to today's profusion of synthetic chemicals. The biologically active carbonbased pesticides, which came to market in Carson's lifetime, brought new abilities to combine chemical compounds for the betterment of humanity, but they also offered the potential to produce a "battery of poisons of truly extraordinary powers," she wrote. In making her case in Silent Spring, Carson pointed to well-documented die-offs of birds, fish, and other life forms following the misuse of pesticides. Her cause was also aided by a growing awareness that DDT and other chemicals she discussed were carcinogens. But the problems documented in Our Stolen Future are harder to witness, cancer is usually not a result, and confounders abound. Although the authors urge a redesign of chemical products to reduce use of endocrine disruptors, it is unlikely EPA will vigorously lead such an effort. According to Paul Anastas, who heads the indus1 7 0 A • VOL. 30, NO. 4, 1996/ ENVIRONMENTAL SCIENCE & TECHNOLOGY/ NEWS
trial chemistry branch, EPA's program to design less toxic "green" industrial chemicals makes no special effort to find less toxic substitutes for compounds with the potential to influence endocrine systems. "We're certainly interested in designing safer chemicals," he said, "but for all endpoints." "It is too premature for regulatory action," says Lamb. "Why do it? We don't know if there are problems, and we may replace one 'bad' chemical with an equally 'bad' one. Right now all we have is a gut feeling in many cases for what should be done." Chemicals and pesticides are controlled by EPA under the Toxic Substances Control Act and the Federal Insecticide, Fungicide, and Rodenticide Act, respectively. According to Sandra Tirey, Chemical Manufacturers Association assistant vice president for regulatory affairs, EPA has ample flexibility currently to require whatever testing is necessary under those and other statutes and regulations. EPA plans to formally revise its testing regime for pesticides and chemicals to make them more sensitive to identifying endocrine-disrupting chemicals. The changes will come through proposed reproductive and development toxicology guidelines, according to Susan Makris, a toxicologist in the EPA Office of Pesticides Program. Although the new tests will not be aimed solely toward endocrine disruptors, they will include a two-generational reproductive study in rats and will examine sperm morphology, count, and motility in males and estrogenicity in females, as well as the age of sexual maturation in the second generation, Makris adds. The guideline has been proposed several times, however, and is not expected to become final this year. Makris adds that at present there is no budget for the EPA Science Advisory Panel, which must review the guideline. However, she and other EPA officials say they expect labs to incorporate the new protocol in their test regime once they see EPA is serious about finalizing the guideline. Jay Feldman, executive director of the National Coalition Against the Misuse of Pesticides, applauds the proposed guideline and increased emphasis on endocrine-disrupting chemicals, but says, "Frankly, this administration has announced a lot of good policies but has failed to provide the resources to carry them out. This is a real problem. A policy that is not implemented does not provide protection and in the end confuses the public. The headline reads, 'The administration adopts policy' but the policy is never implemented." Colborn, he adds, was scheduled to speak at the coalition's conference the day before her book's release.
References (1) Colborn, X; Dumanoski, D.; Peterson Meyers, J. Our Stolen Future; Dutton: New York, 1996. (2) Carson, R. Silent Spring; Houghton Mifflin: New York, 1962. (3) Pinchbeck, D. Esquire, Jan. 1996, 78-84. (4) Wright, L. The New Yorker, Jan. 1996, 42-55. (5) Natural History, March 1996, 42-49.
Jeff Johnson is an associate editor on the Washington staff of ES&iT.
