Environmental▼News one-quarter to one-half of presentday levels, Petrie finds. Over the past 15 years, the scaup have switched from eating native snails and crustaceans to consuming the abundant zebra mussels. At the same time, scaup populations in North America have declined from a high of 8 million birds in 1972 to 3.7 million in 2001, with most of the decline occurring since the mid1980s after zebra mussels invaded the Great Lakes, he says. It is tempting to conclude that selenium contamination from eating zebra mussels on the lower Great Lakes is contributing to the downward spiral in scaup numbers, Petrie says. Even if selenium inputs to the Great Lakes have not
changed much in 15 years, zebra mussels, by filtering vast quantities of suspended matter, have bioconcentrated selenium and increased its availability to the ducks, he says. Zebra mussels can accumulate 20–370 ppm of selenium and still maintain stable populations, Petrie says. Few other species accumulate selenium to such levels, probably because the mussels filter so much more water. Although the Great Lakes basin has many potential sources of selenium, such as coal-fired power plants and landfills, researchers have not yet documented a widespread selenium problem in the lakes, says Peter Hodson, director of the School of Environmental
Studies at Queens University in Kingston, Ontario. Little is known about selenium because the contaminant is not regularly monitored by either the United States or Canada in the Great Lakes, says Alice Dove, watershed scientist with Environment Canada. Nevertheless, studies on North Carolina reservoirs have shown that nontoxic levels of selenium in water and sediments bioaccumulate in the aquatic food chain to levels high enough to kill fish, adds Hodson. If the link between zebra mussels and selenium poisoning is borne out, governments would have to track down the selenium sources and curb releases, he says. —JANET PELLEY
A 2001 expert literature review that concluded hexavalent chromium, Cr(VI), in drinking water is unlikely to cause cancer has been thrown out by the California EPA amid allegations that the scientific panel responsible for the report was manipulated to favor corporate interests. Nevertheless, the University of California’s Office of the President, which organized the blue-ribbon panel, and the panel’s chair, University of California–Davis toxicologist Jerold Last, stand behind the report, which was launched as a review of California’s 1999 public health goal of 2.5 parts per billion (ppb) total chromium. By comparison, the U.S. EPA set a standard of 100 ppb for total chromium in 1991. California’s strict 1999 goal “was based on a flawed study that was never intended to be used for risk assessment and that no other public health agency in the world has used, and that’s what our panel told the state,” Last says. The panel’s controversial findings are also consistent with recent evaluations by the U.S. EPA, the Agency for Toxic Substances Disease Registry, and the International Agency for Research on Cancer.
CORBIS
Allegations of manipulation lead to withdrawal of Cr(VI) report
Erin Brockovich (shown here as played by Julia Roberts) alerted the world to the perils of chromium contamination.
Cr(VI) is a human carcinogen that is widely agreed to cause lung and nasal cancer in anyone who inhales it at high concentrations. But whether Cr(VI) in drinking water causes cancer is controversial. Most experts say that the stomach’s acidic, reducing environment converts ingested Cr(VI) to nontoxic Cr(III). However, some scientists caution that the stomach’s reduction of Cr(VI) could be incomplete. “We don’t know that all Cr(VI) gets changed to Cr(III),” says Max Costa chair of the Department of
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Environmental Medicine at New York University. “Some people change Cr(VI) better than others.” California EPA head Winston Hickox abandoned the panel’s report after hearing allegations from attorney Gary Praglin to the California State Senate in February and March. Praglin, one of the attorneys suing utility Pacific Gas and Electric (PG&E) over this issue, claimed that lobbyists paid by the company tried to stack the panel; that part of the report was copied from industry-sponsored publications; and that consultants had sought to discredit an epidemiological study by ghostwriting a followup that was published as work by the original authors. Dennis Paustenbach, a consultant toxicologist with Exponent in Menlo Park, Calif., and a target of intense criticism by Praglin because of prior work for PG&E, says that the lawyers are trying to discredit the scientific findings by attacking the process. “Praglin has taken dozens of snippets of testimony collected over several months out of context and has strung them together into a story which feels compelling to those who have not had a chance to read all of the testimony,” he claims. “This isn’t a case of industry manipulating science. It’s a case of lawyers manipulating the regulatory process.”
sight and with the urging of several California agencies and legislators, the National Toxicology Program (NTP) has begun conducting a multimillion-dollar two-year rodent cancer study to resolve this uncertainty. The consequences of California’s regulatory decision are high. The recent movie Erin Brockovich popularized the story of a $333 million out-of-court settlement stemming from claims that Cr(VI), which leaked from PG&E facilities and contaminated groundwater in and around the southern California town of Hinkley, caused various illnesses, including cancer. Other suits potentially worth hundreds of millions of dollars are still proceeding through the courts. California plans to review the literature again and propose a new draft public health goal for Cr(VI) this fall. Until that time the state will use the old 50 ppb total chromium standard, according to Office of Environmental Health Hazard Assessment spokesperson Alan Hirsch. The results of the NTP study are not expected until 2006. —REBECCA RENNER
Seabirds on Midway Atoll, a decommissioned Navy base that has been turned into a wildlife refuge, are being exposed to high levels of lead from deteriorating lead-based paint found on several of the islands’ former military buildings, according to research in this issue of ES&T (pp 3256–3260). Although the refuge is now the responsibility of the U.S. Fish and Wildlife Service (USFW), the findings point to the need for better lead cleanup when military bases are shut down and used for other purposes. From early October until August, Midway Atoll National Wildlife Refuge, which is located at the western end of the Hawaiian archipelago, is inhabited by hundreds of thousands of Laysan albatross seabirds. Space is at a premium, and many birds are forced to nest in close proximity to the abandoned buildings.
BRADFORD KEITT
Lead paint on former military bases poses risks to wildlife
Laysan albatross chicks have drooping wings from nesting near buildings with deteriorating lead-based paint on Midway.
Chicks that nest near these structures often develop acute lead poisoning and rarely survive, says Myra Finkelstein, a doctoral student at the University of California–Santa Cruz and lead author of the ES&T study. One of the most noticeable symptoms of lead exposure is a con-
News Briefs Delivering with fuel cells The U.S. EPA is teaming up with the UPS delivery service and DaimlerChrysler to test fuel-cell vehicles under real-world conditions in a project expected to begin later this year, the three organizations announced in May. The project will be based at EPA’s National Vehicle and Fuel Emissions Laboratory in Ann Arbor, Mich. The first vehicle to go into service will be a passenger-sized test car based on the Daimler-Chrysler Mercedes-Benz A-Class, and it will be joined by at least one Dodge Sprinter van in 2004. The test delivery vehicles will be used in typical UPS delivery operations on established routes, so the project will allow the members of the government–industry partnership to evaluate fuel economy and driving performance under varying weather conditions. For more information, go to www.epa.gov/fuelcell.
Ontario to exceed ozone treaty target Canada’s Ontario province is projected to exceed by 44% a 2007 cap for ozone-causing nitrogen oxide (NOx) emissions from the electricity sector, according to a new report by Synapse Energy Economics, a Cambridge, Mass., consulting firm. The report estimates that even with new selective catalytic reduction controls, emissions will total 56 kilotons (kt) in 2007. If the government replaced the two dirtiest coal-fired power plants, at Nanticoke and Lambton in southern Ontario, with combined cycle gas turbines, emissions would total 18.6 kt NOx in 2007, 52% below the 39-kt cap. A Clean Path to Ozone Annex Compliance: Phasing Out Ontario’s Coal-Fired Power Plants, written for the Sierra Club, is available at www.synapse-energy.com.
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PHOTODISC
Others are not so sure. John Froines, head of the University of California–Los Angeles’ Center for Occupational and Environmental Health, says that he quit the panel over worries about potential conflicts of interest among fellow members, that the report was rushed, and that the findings that there were no health risks associated with drinking Cr(VI) in water were too definite. “The issue is not that I think Cr(VI) has been shown to cause cancer,” Froines says. “But there is sufficient uncertainty that we can’t say there is no problem. How to address the uncertainties in the possible chromium-related cancers is an important public policy issue to be considered by state authorities.” In the past 10 years, California has become a crucible for the debate on chromium as the state crafts the nation’s first regulatory standard specifically for Cr(VI) in drinking water amid massive class action lawsuits. Previous drinking water standards have focused on total chromium, because of the difficulty in analyzing for Cr(VI). However, with no clear recommendation in
