Mercury Rising

By Heather Heilman
Photography by Jackson Hill

Bluegill, sunfish, white crappie, largemouth bass, red-ear sunfish, redfish, speckled trout, flounder, white trout, red snapper, crab, shrimp, oysters and crawfish. Those are the kinds of seafood April and Damien Foret eat, although April can't identify all of those fish by name.

"Whatever he catches, I eat," she says. "He brings it home and he cleans it. I don't know what kind of fish it is."

The Forets are a young couple from around Bayou LaFourche. They're sitting in the public health clinic in Cut Off, La., answering questions about what kinds of fish they eat and where it comes from. Damien wears a camouflage T-shirt with a picture of a deer on the front. He works on an oil rig, but lives to fish and hunt. The couple eats seafood at least twice a week, and except for an occasional can of tuna, Damien and his friends catch all of it in the waters of south Louisiana.

That's why they're here in Cut Off, getting ready to give a blood sample. They're concerned about the harmful effects of mercury, and they know that eating fish is the most significant source of exposure to the heavy metal for most people.

The Forets have volunteered to participate in the Mercury Project, a study directed by William Hartley, associate professor and co-director of the Environmental Diseases Prevention Research Center at Tulane's School of Public Health and Tropical Medicine.

The Mercury Project is being conducted under the auspices of the Environmental Diseases Prevention Research Center, which is affiliated with the Centers for Disease Control. Funding for the project comes from the Louisiana Department of Health and Hospitals and the Louisiana Department of Environmental Quality. The study is in part the result of lobbying by organizations and individuals in the community who became concerned about the levels of mercury that were appearing in Louisiana fish and convinced the state legislature to appropriate some money to look into the issue.

SOMETHING FISHY
While Hartley directs the project, Angela Machen and Tonya Shropshire are the ones who load up the car and travel around southeast Louisiana to talk to study participants and take their blood samples. Machen is a doctoral student at the School of Public Health, and Shropshire is a registered nurse who received her master's degree in public health last fall.

Their goal is to find 150 families from a five-parish area around New Orleans who eat locally caught fish at least once a week, in order to test the level of mercury in their blood.

"Fish are great food, but they accumulate all kinds of chemicals," Hartley says. One of those chemicals is mercury, which gets into the environment mostly through the burning of fossil fuels. Medical- and hazardous-waste incinerators can also be a significant source of mercury contamination. Chlorine plants release some mercury into the air, and strip mines expose mercury buried in the earth. Mercury in the air is washed out when it rains and gets into the water and soil. Mercury exposed by strip mining will run off into the water. Some industries, like paper mills, release relatively low amounts of mercury directly into the water.

Across the country, about 2,000 mercury advisories have been issued on particular lakes and rivers in more than 40 different states. The problem in Louisiana does not seem to be as severe as in some other states, particularly in the Great Lakes region.

Nevertheless, Louisiana has a lot of fishermen and a lot of water--and it's just the kind of acidic, highly organic water that contributes to the rapid conversion of inorganic mercury into organic methyl mercury, which accumulates in fish.

"Methyl mercury is the most dangerous kind of mercury because it crosses into the brain and nervous system," Hartley explains.

The state of Louisiana has been testing levels of mercury in fish for a decade. At this writing, the state has 20 mercury advisories on Louisiana lakes and rivers and the Gulf of Mexico. In most cases, the advisories only apply to particular species of fish, and only to the consumption of the fish by children under 7 and women who are pregnant, breastfeeding, or planning on becoming pregnant. The main concern with mercury is that it may damage the developing nervous systems of babies and small children, although it is toxic to the kidneys of both adults and children. In adults, low to moderate mercury exposure will usually have no permanent adverse effects and any symptoms will disappear once exposure is stopped.

It's a problem that is receiving a growing amount of national attention. The Food and Drug Administration recently issued a warning that pregnant women, or women who plan on becoming pregnant, should not eat shark, swordfish or king mackerel at all because of mercury accumulation in those fish. The National Academy of Sciences estimates that as many as 60,000 mothers and children might be affected by mercury contamination, which could have a significant impact on the numbers of children who struggle in school.

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