Environmental▼News lightly than assessments under the ESA, where mistakes in registering pesticides are viewed as potentially irreversible and biologists are directed to preclude extinction, Senatore explains. Clark charges that the proposed rules were drafted by the office of Craig Manson, the Assistant Secretary of the U.S. Department of the Interior, whose political motivation is to ease the way for farmers to use pesticides, not to protect declining species. The recommenda-
tions of career biologists at FWS and NMFS were totally disregarded, and the new rules were drafted with industry help and support, Senatore charges. Many career staff at FWS and NMFS would not speak to ES&T—some were fearful of reprisals by Administration officials—but confirmed that environmentalists’ claims of industry interference were accurate. EPA’s poor compliance record with the ESA is now being played out in the courts, Senatore says. On
January 22, the U.S. District Court in Seattle ordered EPA to consult with NMFS on the adverse effects of pesticides on endangered salmon and established interim protections that ban application of 38 pesticides near streams in Washington, Oregon, and California. Similar lawsuits over the impact of pesticides on sea turtles in the Chesapeake Bay and California’s red-legged frog are threading their way through the courts, Senatore says. —JANET PELLEY
Mercury woes appear to grow more slowly than normal along a particular circuit in their brains. However, the researchers did not find a link between prenatal exposure to PCBs and electrical signal latencies. The study, one of the first to look for neurodevelopmental effects in older children, is likely to fuel the RHONDA SAUNDERS
Two new studies find that problems arising from mercury exposure may be more severe than previously thought. Children born to women who ate large amounts of seafood containing methylmercury during pregnancy can suffer brain development that persists at least into adolescence, according to results from a large, long-term study of Faroe Islanders. Meanwhile, a preliminary estimate from the U.S. EPA finds that about 630,000 infants are born every year in the United States with unsafe levels of mercury in their blood, which is roughly twice the agency’s earlier calculations. The U.S. Food and Drug Administration (FDA) currently advises pregnant women, nursing mothers, and young children to avoid eating fish with high levels of mercury, although many consumer and environmental groups argue that the warnings are inadequate. The study of children on the Faroe Islands—several islands in the Atlantic, northwest of Scotland, where inhabitants eat a lot of fish and whale meat—was led by the Harvard School of Public Health’s Philippe Grandjean. Because of their diets, Faroe Islanders are exposed to high levels of mercury, PCBs, and other contaminants. The researchers found that 14year-olds who had high levels of mercury in their umbilical cord blood at birth continued to show neurological deficits previously identified at age 7. In particular, the children transmitted electrical signals
Children whose mother ate large amounts of mercury-contaminated seafood during pregnancy could suffer unique problems.
continuing debate about the health effects of this toxic form of mercury. According to Grandjean, the study suggests that “when mercury gets into the brain of a fetus, it will cause damage and that damage will be permanent.” The researchers also found latencies in electrical signals from other parts of the brain in 14-yearolds who are linked to current mercury exposure, which suggests that postnatal exposure may damage brain functions in a different way than during fetal development, according to the authors. More than 850 14-year-olds participated in the study, which began with over 1000
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mothers and their children. However, the mercury picture that is emerging from modern longterm studies is not entirely clear. A second large long-term investigation on the tropical Seychelles Islands, where inhabitants also eat lots of fish, has found little evidence that mercury exposure during brain development causes harm. The difference may arise from the Faroe Islanders’ unique, whale-rich diet, according to University of Rochester neurologist Gary Myers, one of the principal investigators in the Seychelles study. He notes that toxins other than mercury in the whale meat might explain some of the detrimental effects. Meanwhile, a new estimate of the number of children born with unsafe blood mercury levels was presented by EPA scientist Kate Mahaffey in January at the National Forum on Contaminants in Fish. The new estimate is based on a recent analysis of methylmercury in maternal and fetal umbilical cord blood that found that the mercury level in fetal blood is 1.7 times higher than that in maternal blood—not one to one as previously assumed (Environ. Health Perspect. 2003, 111, 1465–1470). This means that a mercury level of only 3.5 parts per billion (ppb) in a mother’s blood would be enough for her fetus’s blood to exceed the 5.8-ppb safety level. Nearly 16% of U.S. women have mercury blood levels of 3.5 ppb or higher, according to figures from the U.S. Centers for Disease Control. —REBECCA RENNER
