Degrees of Mercury

Do government safety advisories go too far or not far enough?



Welcome to the Heavy Metals Age. Virtually every day new reports assault us like anti-aircraft flak with dire news about the toxic burdens our bodies endure. Maintaining a healthy diet isn’t just a matter of scaling the food pyramid to better health. Advice about reducing fat and cholesterol is often tempered by warnings about PCBs and heavy metals in fish and seafood. Even then, questions arise: Do government warnings go too far, or not far enough?

Such is the case with the latest government advisories about mercury levels in fish. In January the U.S. Food and Drug Administration (FDA) issued a consumer advisory for vulnerable populations—nursing mothers, children under 6, pregnant women and those planning to get pregnant—to avoid eating large fish that are higher on the food chain and thus accumulate higher levels of methylmercury, which can be toxic to the nervous systems of young children and developing fetuses. Species like shark, swordfish, king mackerel and tilefish can contain mercury levels above one part per million (ppm) and should be avoided. For other fish species, the FDA recommends that vulnerable populations eat no more than 12 ounces per week.

Then in March, the Montana Department of Public Health and Human Services (DPHHS) issued its own advisory based on recommendations spelled out by the U.S. Environmental Protection Agency, which are more stringent than the FDA’s.

Specifically, DPHHS recommends that those women and young children who eat fish from Montana waters should eat smaller fish, eat it less often, and eat only those containing very low levels of mercury and PCBs. To determine those levels, DPHHS provides six pages of charts and tables, listing Montana bodies of water, fish species, sizes, and measured levels of mercury and PCBs.

For instance, a 10-inch Walleye caught in Bighorn Lake contains mercury in concentrations of 0.20 ppm and should be eaten by pregnant women or young children no more than once a month. But a 27-inch Walleye in Bighorn Lake should be avoided altogether. However, a 12-inch Walleye caught in Canyon Ferry Reservoir is safe to eat once a week, as would be a 19-inch rainbow trout. Those recommendations change depending upon if the fish is eaten seasonally or year-round.

Sound complicated? It is, admits Stan Strom with the DPHHS Food and Consumer Safety Section, which issued the advisory. Part of the problem, says Strom, is trying to communicate to consumers the wide array of variables that affect the levels of mercury consumed, such as species size, frequency of consumption, and the consumer’s gender, age and body size, to name but a few.

“My job is to publicize this stuff and present this information in such a way that it’ll do the most good for the most people and still won’t alienate the reader,” says Strom.

But some consumer advocates aren’t buying it. A new report issued in April by the Montana Public Interest Research Group (MontPIRG) and the Environmental Working Group criticizes the FDA, Environmental Protection Agency and DPHHS for what it calls inadequate protections against mercury exposure for young children and pregnant women.

According to the report, entitled “Brain Food: What Women Should Know About Contamination in Fish,” if pregnant women follow FDA guidelines, more than one in four—or about 1 million fetuses nationwide—will be exposed to potentially harmful doses of mercury for at least one month of their pregnancy.

The report also finds that about 20,000 fetuses would be exposed to mercury levels that increase their risk of neurological effects for the entire nine months of pregnancy.

“Even though Montana does a better job of reporting mercury than most states, the science they’re using to come up with a safe level of consumption is inadequate,” says David Ponder, executive director of MontPIRG. Ponder notes that FDA consumption advisories are based on the metabolism of an average 150-pound male. In fact, most pregnant women are considerably smaller, increasing their exposure risk by a factor of two to three. Additionally, at least 10 percent of all women already have elevated mercury levels in their blood, according to the Centers for Disease Control.

“When it comes to the FDA’s posture on this, I’m troubled by it,” says Strom, who agrees that FDA guidelines probably don’t go far enough to protect children and pregnant women, which is why Montana follows EPA recommendations instead. Ironically, Montana does a better job than states like Idaho and Wyoming, which don’t even track mercury levels in fish.

“A lot of tuna fish off the shelf in cans, which there’s no FDA consumption limit on, is much higher than sport fish in Montana,” says Strom. “It makes it look like Montana’s fisheries are much, much worse than other states. And that’s not really true.”

But Ponder remains skeptical of the state’s confusing advisory system, and asks whether Montana fishermen are likely to pore over the health department’s complicated chart system when deciding which fish to eat.

“I’d like to think so,” says Strom. “But indications are that a lot of consumers just dismiss the whole thing out of hand as being so much environmentalist hand-wringing.”

Just as importantly, says Ponder, the state health department should be more aggressive in its assessment of how mercury is getting into Montana fish. In one section, the DPHHS advisory reads, “Mercury is widespread in the environment and can be found in low concentrations in most soils and rocks. These naturally occurring deposits are the most probable cause of elevated levels of mercury in fish in Montana.”

“That’s bull hockey,” says Ponder. “We know where the mercury is coming from. The leading source of mercury pollution is power plants, and in Montana, the secondary cause is incinerators. They’re a public health agency and they should know that.”

Add a comment