Wednesday, Jul 9, 2008
Millions of fetuses whose mothers eat fish are being exposed to brain-damaging mercury. But critics charge the Bush administration's regulations are like bailing the ocean with a thimble.
Apr 18, 2005 | When children in Dr. Kevin Browngoehl's practice suffer from learning disabilities or attention problems, the pediatrician wonders whether methylmercury in the fish their mothers ate before they were born is to blame. "Once the damage has been done, it appears to be a permanent thing. It's something I can't do much about as a doctor," says Browngoehl, who practices in Drexel Hill, Penn.
Browngoehl explains that mercury travels through a mother's bloodstream, "goes through the placenta, and is concentrated in the brain of the fetus." What's so insidious about the neurotoxin, he says, is that it's likely to present no symptoms in a pregnant woman as it attacks fetal brain cells.
"The mercury is damaging and killing the cells as they're trying to develop areas of the brain that deal with attention and memory," Browngoehl says. "You have a nerve poison being introduced during a critical time of the development of the brain."
Browngoehl's remarks are backed by several alarming studies of mercury in the past decade. One study, sponsored by the U.S. National Institute of Environmental Health Sciences, and Europe's Environment and Climate Research Program, showed that children exposed to mercury in utero did poorly on tests measuring their attention span, memory and speaking abilities. According to the U.S. Environmental Protection Agency, both the brains and nervous systems of children who have been exposed to mercury can be damaged. Their language and visual spatial skills can also suffer.
"Children who suffer the consequences of methylmercury toxicity often appear like other children who may have been affected for a genetic reason," explains Leo Trasande, the assistant director of the Mount Sinai School of Medicine's Center for Children's Health and the Environment in New York. "A child with mental retardation may have had a significant environmental exposure in the perinatal period. But there are no hallmarks." One study found that an affected child could score lower on IQ tests by as little as .20 of a point to as much as 24 points.
The mercury studies are behind the EPA's advisory to moms and would-be moms to avoid eating the most mercury-laden fish, such as swordfish and shark. And to go easy on the tuna. But even with those warnings in place, the agency estimated that as many as 600,000 newborns are being exposed each year. That's 15 percent of the 4 million babies born in the United States each year.
While the Bush administration cajoles women to follow its fish warnings, it's proved unwilling to take on the root of the problem. Fish, after all, are only the pathway of mercury to our bloodstreams. Coal-fired power plants, in the United States and abroad, are the largest source of man-made mercury pollution. But Bush and company stand in the way of international efforts to prevent mercury pollution and are doing little the stop it at home.
Just last month, the EPA adopted new regulations to curb power plants' emissions of mercury pollution. It heralded its new rules as the very first time that such pollution has been regulated from coal-fired power plants. But environmentalists and health officials view the new rule, which includes a pollution trading scheme, as unlikely to make much difference in mercury pollution for more than a decade. "Essentially, the agency adopted a do-nothing approach to mercury for the next 12 years," said John Walke, director of the Natural Resources Defense Council's clean-air program.
Browngoehl compares mercury poisoning to another heavy-metal neurotoxin that once haunted the country: lead. Once common in paint and gasoline, lead poisoned kids and caused lower IQ scores. Mercury is the new lead, he points out, with one crucial difference -- there's a lack of political will to do anything about it. "We didn't say, 'OK, don't eat the paint and don't breathe the air,'" Browngoehl says. "We got the lead out of paint and gasoline. And we still have paint and gasoline. It was a struggle, but people had the political will to do it. People have to decide that this is worth the health of children."
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