plaints rely on the theory that the cumulative pollution in a particular area is already too much, the staffer said. Several SAB members criticized the definition of a pollution burden as too loose, said Don Barnes, SAB staff director. Because the analyses can determine the pollution burden, but they are not risk assessments, the burden cannot be explained as risk, and it does not represent exposure, he said. "The board felt EPA had to be careful about how burden was defined and communicated to the public," Barnes said. Other SAB committee members faulted the analyses for not considering chronic health effects such as asthma a top health problem in poor communities and instead focusing on anite health problems All three analyses rely on Toxics Release Inventory data. Although EPA staffers had to begin with known data, TRI reports do not really represent daily exposures, said Joe DiGangi, a Greenpeace toxicologist who attended the SAB review. The TRI summarizes annual emission estimates, but the company reports do not indicate when a chemical was emitted; they do not include all chemicals, such as dioxin; and they do not take into account chemical re-emission some committee members said. The multitude of chemical releases under the TRI (some 650 chemicals) makes establishing the burden difficult. To address this, the analyses weight the releases according to their toxicity, and the weighted chemicals are added together and treated as if they were one "pseudochemical." The pseudochemical framework involves too many assumptions, several committee members said. "The strength of this is that it covers many exposures, but does it really make scientific sense to combine cancerous and noncanceroi 1 s chemicals to come up with a load?" said Henry Anderson chairman of the SAB committee and chief medical officer for the Wisconsin Department of Public Health The committee suggested the chemicals be disaggregated into units of like chemicals to better indicate what was
driving the pollution burden, said Goode, and EPA staff have begun working on that suggestion. On the upside, all three models are transparent, so they would be easy to explain, said Anderson. They also use existing TRI and state data, and they do not take long to run to do [the investigation] in," he added. A separate committee concern dealt with how EPA might use the models, which is not SAB's bailiwick, admitted Anderson. "Part of the problem is that [EPA] doesn't really have a policy yet," Ander-
son said. "So we don't know what the outputs mean. EPA hasn't said what the magic number is that shows disparate risk." Six months ago, the civil rights office did not have these models, Goode said. "All of the environmental justice projects have presented the agency with a real challenge," said Goode. "We are working on how to get a grip on what our environmental requirements are and how they fit with our environmental justice concerns," she said. CATHERINE M. COONEY
International treaty aims to stem flow of toxics An international treaty signed in September by 57 countries, including the United States, establishes a "first line of defense" against unwanted imports of certain hazardous chemicals and pesticides, particularly in developing countries, according to Klaus Toepfer, executive director of the United Nations Environment Programme (UNEP). UNER together with the U.N.'s Food and Agriculture Organization, will oversee the treaty's implementation. Under the treaty, called the Rotterdam Convention on the Prior Informed Consent (PIC) Procedure for Certain Hazardous Chemicals and Pesticides in International Trade, any chemical that is banned or severely restricted in at least two participating countries cannot be exported without prior permission from the importing country. Through the information exchange facilitated by the treaty, importing countries will be able to decide which chemicals they want to receive and exclude those they cannot according to UNEP. If trade still takes place labeling requirements including information on any potential health and environmental effects should promote safe use The accord becomes legally binding only after 50 countries ratify it. As a first step among multilateral environmental agreements, however, governments have agreed to continue implementing the voluntary PIC procedure, in effect since 1992, with
the new provisions until the convention formally enters into force. Substances that fall under the PIC requirements include five industrial chemicals and 22 pesticides. Some of targeted chemicals are nearing the end of their useful life cycle—such as aldrin, dieldrin, and polychlorinated biphenyls— and some are still widely in use, such as DDT. Although DDT is banned in the United States, it is still the chemical of choice in many countries for controlling mosquitoes that carry malaria, said Cadileen Barnes widi EPA's Office of Pesticide Programs. "It happens to be a pesticide that's very cheap and not acutely toxic," she added. Acutely toxic pesticide formulations that present a hazard under conditions of use in developing countries, such as parathion and methyl-parathion, also are included on the PIC list. These two pesticides have caused a large number of accidental poisonings because their application restrictions are so stringent, said Jim Willis, UNEP's chemicals director. "But just because they're in PIC doesn't mean they can't be used safely," Willis added. "It just means mat these [importing] countries need to keep an eye out for them and make tiieir own decision on whether thev can use them safely" Many more substances are likely to be added to the list in the future according to UNEP. The chemical industry and environmental groups alike have applauded the accord as a step in the right direction to providing
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Unwanted and obsolete stockpiles of toxic chemicals and pesticides have accumulated in virtually every developing country, according to the United Nations Environment Programme.
greater public and environmental protection. The Global Crop Protection Federation, which represents manufacturers of pesticides, herbicides, and fungicides, has made PIC compliance a condition of membership. In the absence of effective regulatory regimes, however, "it's a nice concept that won't get very far," said Clif Curtis, toxics campaign director for the World Wildlife Fund. Pointing to China and India as examples, he noted that trade-related controls are moot when chemicals are produced and used domestically because no border crossings occur that trigger the advised consent and information related requirements under PIC. Likewise, developing countries often lack even rudimentary chemical programs and do not have strong customs and enforcement infrastructures. In these instances, Willis conceded, PIC will not do much to stem the flow of unwanted hazardous chemicals. The potential for such substances to be exported under lax controls is great, according to an analysis of U.S. Customs shipping records by the Foundation for Advancements in Science and Education (FASE), a public interest group. From 1995 through 1996, more than 338 million pounds of hazardous pesticides were exported from U.S. ports alone, the majority going to destinations in the developing world, FASE found. During this period, at least
21 million pounds of pesticides banned for use in the United States were exported. The Pesticides Trust, an independent charity, has been pushing for a commitment of financial and technological assistance from developed countries to bring
about more effective implementation of the PIC procedure. "[Developing countries] need the funds for training, identifying severely hazardous pesticide formulations that cause problems in their countries, establishing poison centers and monitoring systems, and capacity building," said Barbara Dinham, the trust's international projects officer. For other substances to be considered for inclusion as a severely hazardous pesticide formulation, information has to be compiled on specific incidents in developing countries, the adverse effects, and the way in which the formulation was used. The trust's experience, Dinham said, is that evidence at such a detailed level is extremely difficult to obtain. "It's important to keep PIC in perspective," Dinham said. "It is a limited and targeted treaty . . . [which] by itself will certainly not transform chemical control, use, misuse, and ignorance." —KRIS CHRISTEN
Cost-effective testing effort demonstrates new cleanup technologies In a five-year testing campaign that cost less than $20 million, researchers at the Advanced Applied Technology Demonstration Facility (AATDF) validated the performance of 10 innovative cleanup methods targeting difficult soil and groundwater contamination. The project's final report, which recommends that the Department of Defense (DOD) begin using several of the technologies, was scheduled for publication this October. The effort included "the first truly statistically valid phytoremediation project for fuels in soils in the U.S.," claimed Calvin "Herb" Ward, AATDF director and environmental science and engineering professor at Rice University, Tex., where the AATDF is headquartered. The demonstration "showed absolutely conclusively that phytoremediation is capable of reducing the concentrations of PAHs in soil," Ward said. For treating groundwater contaminated with chlorinated solvents, or combinations of hydrocarbons and chlorinated solvents, the AATDF project found that passive/semipassive remediation using "funnel and gate" technology with zero-valent iron was effective. The demonstration begun by Ward's group has been taken over by the Naval Air Station in Alameda, Calif., which is using the technology to control a groundwater plume that would otherwise threaten the San Francisco Bay. Not all of the technologies evaluated in the project proved worthy of application at DOD sites. Because academic researchers tend to underestimate the costs of applying a technology, Ward hired consulting engineers to come up with credible cost estimates. AATDF's activities also included the creation of experimental controlled release test systems and the publication of a technology practices manual for surfactants and cosolvents. "We feel like we got a lot of bang for the buck," Ward said. Most federal field technology demonstrations cost between $2 million and $4 million, and some go as high as $10-15 million, he noted. —KELLYN S. BETTS
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