Department of Health and Human Services. In keeping with the Republicans' stated goal to inject "common sense" into EPA's rule-making process, both bills include a new requirement that EPA publish a risk assessment for new standards. The assessment must use the "best available," peer-reviewed science and provide "informative and understandable" descriptions in documents that support the drinking water regulation. For example, the legislation directs EPA to describe the populations affected by the health effects estimates, the expected risk to those populations, upper or lower bound risk assessments, peer-reviewed studies reflecting the estimates of health effects, and the methodologies used to reconcile inconsistencies in the data.
EPA has begun working on a process to select contaminants based on risk, as required by the new drinking water bills. The agency also would have to seek public comment on several issues, including benefits from compliance with proposed regulations and the varying costs and benefits from alternative standards. Agency officials admit that the new requirements will push EPA analysts to do more work before a contaminant is regulated, a move that is expected to slow the regulatory process. But the trade-off is worthwhile, the officials said. "In general, we support the bills," said Barbara Elkus, acting deputy director, Office of Ground Water and Drinking Water. The agency has already begun working on a process to select contaminants based on risk, said Steve Clark, chief of the Drinking Water Branch. EPA, like all federal authorities, has been conducting cost assessments for its standards under an Executive Order issued during the Reagan years. "The real change," Clark said, "will be in how we select the contaminants." EPA also is pleased with the
new timetable of five contaminants every five years as well as the bill's flexibility in allowing the agency to regulate as few or as many pollutants as it finds necessary, Elkus added. Environmental groups support the House version because of several provisions, including the
community right-to-know requirement and language for a radon standard. But the new regulatory schedule has some groups worried. "There is the potential for very little regulation," said Paul Schwartz of Clean Water Action. —CATHERINE M. COONEY
Endocrine disruption: Potent combinations Synthetic estrogens that are individually weak have up to 1000 times more estrogenic potency when combined, according to a study published in the June 7 issue of Science. Looking at the pesticides dieldrin, toxaphene, and endosulfan, the authors found their individual potency is about 1/10,000th that of the natural estrogen 17-(3-estradiol. However, that difference was nearly closed when the pesticides were combined with similar estrogendisrupting chemicals. The chemicals' potency in combination was screened using yeast to which human estrogen receptors were added, according to the authors. The results support an earlier in vivo study by John A. McLachlan of TulaneXavier Center for Bioenvironmental Research, one of the current report's authors, who found sexual development of turtie eggs to be greatly affected by combinations of singularly weak polychlorinated biphenyl congeners, the authors noted. The study may resurrect recently discarded theories, said S. Stoney Simons, Jr., of the National
Institutes of Health in an introductory article, including the possibility of multiple receptor binding sites (Science 1996, 272, 148992). Also released in June was a consensus statement from 18 scientists concerning the significance of hormone-disrupting chemicals. It urged that greater research, communication, and other actions be taken to address the threat these chemicals pose. Among a host of recommendations, the scientists said more research should be focused in this field; the public should be made more aware of the problem; and manufacturers should assure consumers their products are safe, provide names of all chemicals used in products, and demonstrate that these chemicals pose no developmental health hazards. The document grew from a meeting held last year under the auspices of the International School of Ethology at the Ettore Majorana Centre for Scientific Culture in Erice, Sicily, which followed from the so-called Wingspread Conference held in 1991. —JEFF JOHNSON
HEALTH ADVISORY
Fish advisories rise; mercury a major cause Mercury is the most pervasive pollutant leading to U.S. fish consumption advisories, according to a new EPA report. The analysis of 1995 advisories shows that mercury accounted for 1306 consumption advisories, followed by polychlorinated biphenyls (438 advisories), chlordane (122), dioxin (52), and DDT (35). These five contaminants made up 95% of all advisories. The number of water bodies with fish advisories (1740) is 14% higher than in 1994 and 36% higher than in 1993, EPA reports. These water bodies included 4% of all U.S. river miles, all of the Great Lakes, and 15% of all lake acreage. One of the chief sources of mercury is coal-fired electric utilities, the report notes. Mercury standards for utilities were stalled, however, earlier this year when the agency announced a delay until November of a strategy to control utility toxic emissions, including mercury. Required under the Clean Air Act, the report was to be forwarded to Congress by November 1993.
VOL.30, NO. 8, 1996/ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS • 3 3 1 A
