lecular and cellular mechanisms to determine if observed effects are the result of endocrine disruptors or other causes; studies of ecological endpoints to see if observed changes in a single organism are transferred to the entire population; and analysis of chemical structures of suspected compounds to determine what makes chemicals active or inactive endocrine disruptors. Structural relationships are also being examined by the National Institute of Environmental Health Sciences (NIEHS), according to Kenneth Korach, chief of the NIEHS Laboratory of Reproductive and Development Toxicology. The lab is analyzing structures through molecular modeling, searching for the chemical keys that open a receptor's lock and trigger hormonal activities. Korach's group hopes to eventually develop a predictive, screening device. Of its $280 million budget, NIEHS spends about $30 million a year on endocrine-related research—$24 million in external grants, $5 million in-house—according to George Lucier, director of the NIEHS Environmental Toxicological Program. Lucier said NIEHS and the National Toxicology Program (NTP) are particularly interested in the dose-response relationship for endocrine disruptors. "We have little doubt that [endocrine disruptor chemicals] contribute to human disease to some extent but the big question is how much especially at low levels " Lucier also is responsible for NTP research, which is primarily funded by NIEHS, and conducts lexicological evaluations on specific agents. NTP researchers are beginning a multigenerational study of animals exposed to six or seven specific suspected endocrine disruptors. The $700,000per-year study will consider highand low-dose exposures cancer reproductive capacity (both male and female), neurological, and immunological endpoints. The chemicals include endosulfan (a pesticide) methoxychlor (a DDTlike pesticide with an estrogenic metabolite) vinclozolin (an antiandrogen fungicide) genistein (a natural phytoestrogen) and others that have not been selected
EPA report targets 10 key research areas Ten broad categories of endocrine disruptor research needs are identified in a report generated by EPA-sponsored workshops held last year. The report will serve as the basis of a national examination of this issue being conducted by a committee of the National Science and Technology Council, which advises the president on federal research efforts. The EPA workshop brought together some 90 invited participants representing government, academic, industry, and public interest groups as well as more than 200 observers to discuss the hypothesis that humans and wildlife have suffered adverse health effects from exposure to endocrine-disrupting chemicals. Generally the group believes the hypothesis warrants concerted research on the effects on development of reproductive capability, on improved exposure assessment, and on the effects of mixtures, according to the report. The report identifies as the most important research area the potential effects on the "development of reproductive capability at multiple phylogenetic levels." It also identified 44 research needs spread among 10 areas: basic research, biomarkers, exposure determination, exposure follow-up, mixtures, multidisciplinary studies, risk assessment methods, hazard identification, and sentinel species. The report is scheduled to be published in the August issue of The National Institute of Environmental Health Sciences' Environmental Health Perspectives. —JEFF JOHNSON
Lucier also mentioned his personal interest in ongoing NIEHS research on dioxin, an endocrine disruptor, which is looking at human and animal dose-response relationships. Also being planned is a new NTP center, Lucier noted, which will be in partnership with industry. The center's role will be to generate peer-reviewed estimates of human risk from exposure to reproductive and developmental toxicants, including endocrine disrupters. At the request of EPA and the Department of Interior, a National Research Council committee is assessing the strengths and weaknesses of existing research in hormone-related toxicants and will present its report laying out research priorities in late spring of next year. The committee's charge is broad, and its members include scientists whose studies first brought the issue to national attention and researchers who have been most vocal in attacking its theoretical underpinnings. Industries that produce suspected endocrine disruptors have also initiated new research programs. In particular, the chemical industry is funding a $1.5 milliona-year endocrine disruptor research program at the Chemical Industry Institute of Toxicology. That program plans research on receptor-mediated mechanisms;
assessment of endocrine modulation in animals; metabolism, disposition, pharmacokinetics, and homeostasis of such chemicals; and biomathematical modeling of reproductive endocrine systems. Also the Endocrine Issues Coalition, formed early this year and made up of the Chemical Manufacturers Association (CMA), Chlorine Chemistry Council, National Crop Protection Association, Society of the Plastics Industry, American Forest and Paper Association, and American Petroleum Institute, meets every few months to share industry research, according to Sandra Tirey, CMA assistant vice president of regulatory affairs. "We take this issue seriously and understand the need for research people that the products we make safe " she said A coalition document summarized some 35 industry-funded research programs under way in this area at universities and contract laboratories. Of particular importance, Tirey said, is a study monitoring 30 rivers for levels of nonylphenol and nonylphenol ethoxylate (suspected estrogen mimics that break down from a class of commonly used chemicals), another study examining breast cancer epidemiology, and a research program looking into biodegradation of nonylphenol ethoxylate. JEFF JOHNSON
VOL.30, NO. 6, 1996/ENVIRONMENTAL SCIENCE & TECHNOLOGY/NEWS « 2 4 3 A
