Chicago Tribune, August 30, 2008

STUDY: WOMEN LIVING IN MERCURY'S SHADOW

[Rachel's introduction: In the northeastern U.S., nearly one in five women of child-bearing age have eaten so much mercury-contaminated fish that the toxic metal in their blood would pose a risk to their fetuses, compared with one in 10 nationally.]

By Michael Hawthorne, Tribune staff reporter

The nation's first region-by-region analysis of mercury in women's blood shows vast differences based on where they live, with the highest levels found in the Northeast.

There, nearly one in five women of child-bearing age have eaten so much contaminated fish that the toxic metal in their blood would pose a risk to their fetuses, compared with one in 10 nationally, the federally financed study found.

Women in the Midwest generally had much less mercury in their bodies; less than 3 percent exceeded a safety level intended to protect the developing brain before birth.

The study also found that women who make more money tend to have higher mercury levels. That may be because they are better able to afford expensive seafood, such as swordfish or high-grade tuna, that often is more contaminated.

Within the otherwise troubling analysis there were some glimmers of welcome news. Nationally, the percentage of women with high mercury levels declined from 16 percent in 2000 to 10 percent four years later, the most recent data available. Levels of mercury also dropped most dramatically among the women with the most exposure--a decline that occurred, the authors noted, even though those women were eating the same amount of seafood.

That finding suggests consumer advisories about mercury in fish are starting to work, the researchers argue. The seafood industry and top officials with the Food and Drug Administration have insisted that advising women about high- and low-mercury species would scare women away from eating seafood altogether.

"Women are a lot smarter than they have assumed," said the study's lead author, Kathryn Mahaffey, who until this week was a top scientist at the U.S. Environmental Protection Agency. "They're eating fish, but they're choosing more wisely."

Medical experts agree that on balance, eating fish is good for most people. Seafood generally is a low-fat source of protein, and some fish, such as salmon and sardines, are rich in omega-3 fatty acids that are thought to help prevent heart disease and stimulate brain development.

But studies have found that regular consumption of mercury- contaminated fish can offset those benefits. Exposure to mercury in the womb, mostly from fish eaten by mothers, can irreversibly damage the brain before birth, causing subtle delays in walking and talking as well as decreased attention span and memory.

After an extensive review, the National Academy of Sciences, the nation's leading scientific advisory body, concluded two years ago that Americans need to eat more fish but should vary their choices and, in some cases, avoid certain species altogether because of mercury contamination.

The newest study--financed by the EPA and based on blood samples and fish consumption data collected by the Centers for Disease Control and Prevention--was posted this week on the Web site of Environmental Health Perspectives, a journal published by the National Institutes of Health.

The peer-reviewed study found that 10 percent of U.S. females ages 16 to 49 had mercury levels in their blood exceeding 3.5 parts per billion. Previous studies have shown that level causes the amount of mercury in a fetus to exceed the EPA's safety limit of 5.8 parts per billion.

In coastal states, 16 percent of women exceeded the limit, compared with 6 percent among their inland counterparts, who generally eat less fish.

Levels among the most exposed women are dropping but remain a concern, said Mahaffey, who had a long career at the EPA as one of the agency's top toxicologists. Her analysis found that the amount of mercury in those women has declined from 7.2 parts per billion to 4.4 parts per billion since 1999.

Michael Bolger, an FDA toxicologist, agreed that more awareness of mercury's dangers appears to have led many women to choose seafood that tends to be less contaminated. But Americans still don't eat enough fish, Bolger said.

The FDA in particular has been criticized for failing to do more to protect women and children from mercury exposure. A 2005 Tribune investigation found that supermarkets routinely sell fish that are highly contaminated with the toxic metal, in part because the federal government does not inspect seafood for mercury before it is sold.

Moreover, the government's consumer advisory does not reflect its own testing data. The FDA/EPA advisory tells pregnant women, young children and other at-risk groups to not eat shark, swordfish, king mackerel and tilefish because of high mercury levels. It also cautions those groups to limit their overall fish consumption to 12 ounces a week, including no more than 6 ounces of canned albacore tuna.

Yet the advisory is silent about other commonly sold fish that contain even more mercury than albacore, including grouper, orange roughy, Chilean sea bass and marlin.

In response, physicians groups and several states, including Wisconsin and Minnesota, have issued their own warnings that caution women and children against eating a wider variety of species. Likewise, many supermarket chains have posted warnings.

The seafood industry has financed research suggesting that mercury warnings are scaring women away from seafood. As a result, industry representatives contend, those women are depriving their children of important nutrients.

"There is a lot of confusion out there about what women should do," said Jennifer Wilmes, a dietitian for the National Fisheries Institute, an industry trade group. "The worst thing you can do, of all of your options, is to eat no fish or very little fish."

mhawthorne@tribune.com

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