SAB advisory panel rejects dioxin risk characterization

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ENVIRONMENTAL NEWS SAB advisory panel rejects dioxin risk characterization SCIENCE Wetlands regulations need overhaul, says NRC report, 304A > M T B E detected in survey of urban groundwater, 305A i Integrating environmental databases, 305A GOVERNMENT States turning to voluntary programs to speed cleanups, 306A Clinton to cut environmental health, research programs, 307A Low-level radioactive waste site receives go-ahead, 308A SOCIETY Study encourages firms to find hidden environmental costs, 309A : Browner pledges to visit "environmental justice" sites, 309A

BRIEFS Economic impact of Southern California air pollution regulations, 310A

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n advisory panel to the EPA Science Advisory Board (SAB) rejected on May 16 EPA's proposed risk characterization for dioxin. The decision throws the long-running EPA dioxin risk assessment into confusion and makes the Agency's stated goal of finalizing its review of dioxin by next September highly unlikely, according to EPA officials. It also comes at a time when the Agency is proposing new regulations for several classes of incinerators that are primary emitters of dioxin. The conclusion followed two days of review in which the panel agreed with most of the 2000page risk assessment, released last September, but found fault with the final volume that characterized the risk of dioxin to humans. The risk characterization chapter is intended to guide risk managers in devising management schemes to protect public health. Panel members made clear that the Agency need not modify the exposure or health chapters, which make make up the lion's share of the assessment, and in large part they accepted the assessment's conclusions. The panel's concerns about the risk characterization section, however, may result in the delay of the final assessment package until the end of the year or later, said Robert Huggett, EPA assistant administrator for research, at a House hearing May 24. In preparation for the review, the SAB created two advisory panels, one to assess health chapters and another to examine exposure sections. In all, 39 scientists made up the two panels, which will report their conclusions to the SAB executive board. It was hoped that the comments

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would be ready in time for the executive board to act at its next quarterly meeting in late July, but it was unclear whether additional meetings of the advisory panels might be called. The board is to offer its comments to EPA, based on its review of the total report, public comments, and the panels' recommendations, before the Agency issues a final risk assessment and characterization. The dioxin risk assessment and characterization found dioxins to be a probable human carcinogen and raised concerns about noncancer health effects. It presented a detailed examination of exposure pathways from air deposition to the human food chain; it also provided data showing that dioxin body burden was already near levels that trigger health effects for some people [ES&T, January 1995, p. 24A). In general, the review panels supported the exposure sections and backed, for instance, EPA conclusions that anthropogenic activities are responsible for dioxins and that meat and milk are the primary pathways to humans. Still, they noted, major data gaps exist; in some areas peerreviewed studies are few. Agency officials, however, discussed several ongoing studies that will address the missing data, including development of an atlas of dioxin emissions that ties air emission plumes to weather patterns. On the health side, several panel members questioned whether the data supported conclusions drawn in the assessment and risk characterization. In particular, they said more explanation is needed regarding EPA's use of toxic equivalency factors, EPA's belief that there is no threshold for dioxins' effects, and its assertion that current body burden

0013-936X/95/0929-302AS09.00/0 © 1995 American Chemical Society

levels are within an order of mag­ nitude of causing health effects. "If we endorsed [the risk char­ acterization] subject to minor cleanup at this point it would not represent a consensus," con­ cluded Morton Lippmann, a member of the SAB executive board and chair of the health panel. There was a strong need to "sharpen up" portions of the re­ port, he added. The panels' review of the risk characterization itself was pre­ sented by John Graham, head of the Harvard Center for Risk Anal­ ysis. Despite strengths, Graham said, the characterization lacked balance, especially concerning cancer. For example, he said, po­ tency figures for negative health effects were spelled out but pro­ tective effects that have been at­ tributed to dioxin exposure were not provided. Also, uncertainties in EPA's position were not seri­ ously analyzed or clearly por­ trayed, he said, and EPA's risk characterization for noncancer effects did not allow use of incre­ mental analysis of regulatory al­ ternatives. Graham said he worried that EPA's risk characterization would leave risk managers "naked and in the cold" when making decisions about rules in the years ahead. He urged that a new risk characterization be drafted by risk managers outside EPA. Linda Birnbaum, director of the EPA Environmental Toxicol­ ogy Division, defended the risk characterization as sufficiently reviewed by outside researchers. Speaking after the meeting, she said the Agency may have made a mistake by not making the role of outside scientists clearer. There is a need to make EPA's reasoning "more transparent" so managers could better use and trust the material, she said. "In some cases, we didn't make it clear how we moved from A to B, bu they are not telling us we need new data." —JEFF JOHNSON

EPA research faces major cuts

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ederal funding for environ­ mental science faces an uphill battle in the new Congress, judging from the 1996 fiscal year House and Senate budget resolu­ tion and the 1995 rescision con­ ference report. "Disappointing" was how Jo­ seph K. Alexander, EPA deputy assistant administrator for sci­ ence, termed the proposed cuts. He noted that in some research areas EPA got off easier than other federal agencies, but several programs proposed for elimina­ tion are key to new directions EPA hopes to take. EPA science programs pro­ posed for elimination in 1996 budget resolutions include the Environmental Technology Initia­ tive (ΕΤΙ), environmental educa­ tion research fellowships, and re­ search programs directed to global change and environmental justice, according to congres­ sional budget documents. Alexander was particularly alarmed at the proposed elimina­ tion of the $120 million ΕΤΙ and $10 million fellowship programs. ETI's elimination will curb devel­ opment and verification of new environmental technologies. Wip­ ing out the fellowships would de­ stroy a new program in which 2400 students applied for 100 fel­ lowships in its first trial year. "Maybe we haven't made this clear to Congress, but there is a need to recruit bright grad stu­ dents for environmental science careers," he said. "This isn't a pro­ gram to train a new generation of tree huggers but to train the best professionals for jobs in state and local government, industry, and the regulated community." Although budget resolutions show congressional intent, they are merely federal spending blue­ prints, setting broad limits on funding to be appropriated later in the budget process. That pro­

cess began for EPA May 23 and 24 as the House Appropriations Sub­ committee on Veterans' Affairs, Housing and Urban Develop­ ment, and Independent Agencies wrestled with the EPA 1996 ap­ propriation bill. Subcommittee members plan to mark up the EPA appropriation bill in late June. Subcommittee members warned that cuts lie ahead. EPA Administrator Carol Browner de­ fended her budget but agreed to provide a list of program priori­ ties by mid-June. She also noted that after two years of piecemeal program cuts, the Agency was reaching a point where some ac­ tivities could no longer be done. Browner and members also discussed the 1995 congressional rescision package that cleared the House and Senate but has been vetoed by President Clinton. Re­ scision legislation withdraws funds allocated in earlier years but not spent. The package removes about $1.5 billion from EPA. Most of the cuts ($1.3 billion) are in drinkingwater facility funds. Cuts in the research arena include: $6 million from the Environmental Monitor­ ing and Assessment Program (EMAP); $1 million from "aca­ demic training" programs; $1.3 million in neurotoxicity and health effects research; $5 million unspecified research cuts; and $1.3 million in research-related procurement savings. The resci­ sion would also return $83 mil­ lion earmarked for a research center at Bay City, MI. EMAP cuts come as the Agency is restructuring the $36 million program, said Robert Huggett, EPA assistant adminis­ trator for research, who predicted EPA will now work more closely with other agencies to integrate program resources. —JEFF JOHNSON

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