Lake Huron fish sold without warnings despite health advisories

BAY CITY — A regulatory loophole means that Great Lakes fish containing potentially dangerous levels of cancer-causing dioxin are being sold to consumers without warning.

A Lake Huron whitefish filet is presented at the fresh fish market at Bay Fest in Bay City over the Memorial Day weekend. (Photo by Eartha Jane Melzer/Michigan Messenger)

In its “2008 Michigan Family Fish Consumption Guide: Important facts to know if you eat Michigan fish,” the Michigan Department of Community Health warns that pre-menopausal women and children should avoid all lake trout and large whitefish from Lake Huron because elevated levels of PCBs and dioxin have been detected in samples taken by the Department of Environmental Quality.

But people who encounter these same fish in restaurants and fish markets across the country are unlikely to know about Michigan’s consumption advisory — commercial fisheries are regulated by the Food and Drug Administration which does not regularly screen for dioxin and doesn’t require that consumers be informed about state consumption advisories.

At Bay City’s Bay Fest over the Memorial Day weekend, representatives from Bayport Fish Co. said that most of their fish is sold to Jewish and Chinese distributors in Chicago and New York City.

According to a report by the university-based Michigan Sea Grant Extension, 60 percent of the commercially caught Great Lakes whitefish come from Lake Huron. In 2000, more than 3.5 million pounds of whitefish were harvested from the lake’s U.S.-administered waters.

Lake Huron’s Saginaw Bay is recognized as a federal “Area of Concern” because of contaminated sediments and fish. Dioxin, an extremely toxic byproduct of the chemical manufacturing process, has spread from Dow Chemical’s Midland plant through the Tittabawassee and Saginaw rivers and into the bay. In May, the U.S. Environmental Protection Agency declared it would use its Superfund powers to pressure Dow to move toward clean up of the contamination. In 2008 a sample taken in the bay showed dioxin contamination at 3,000 parts per trillion — more than 30 times the level that requires cleanup under state law.

In a telephone interview last week, Kevin Halfmann, food program specialist with the Department of Agriculture’s food and dairy division, explained that in Michigan the state Department of Agriculture has a contract to inspect commercial fish operations on behalf of the FDA.

“The FDA sends a list of places to go to,” he said, and once a year the department visits each commercial fishing operation and reviews the company’s reports of physical, chemical and microbiological contamination.

In its manual for inspectors the FDA directs the state to “understand the potential hazard” when it comes to environmental chemical contamination, particularly in fish harvested from fresh water.

In determining whether a potential hazard is significant, the agency argues that “[y]ou should be guided by the historical occurrence of environmental chemical contaminants and pesticides at levels above the established tolerances, action levels, or guidance levels in fish for your area.”

It also directs inspectors to make sure “that incoming fish have not been harvested from waters that are under a consumption advisory by a federal, state or local authority based on a determination by the authority that fish harvested from the waters are reasonably likely to contain contaminants above federal tolerances, action levels, or guidance levels.”

If chemical contamination is identified as a likely hazard, fisheries are asked to submit a chemical analysis demonstrating that chemicals in their fish fall within tolerable levels.

In this case, fish must be screened for a list of contaminants, including pesticides and PCBs.

However, because no tolerance level has been set for dioxin, the FDA does not require that the fisheries test for it, even if it is known to be present in water and fish.

In a discussion of dioxin on its website, the FDA explains that the EPA has not completed its assessment of the human health effects of dioxin.

Since about 1995, FDA dioxin monitoring has involved several hundred samples a year, primarily of fish and dairy products from grocery stores and distribution centers across the country. To date the FDA monitoring of dairy products and fish shows that when detectable levels are found, they are generally consistent with EPA estimates for background occurrence of dioxins.

In 1983, a New York Times report on dioxin in Lake Huron carp prompted a scare about eating the fish and wholesalers responded by rejecting thousands of pounds of carp from Michigan. Although the FDA found dioxin at levels between 16-20 parts per trillion in carp from Saginaw Bay and health departments in both Michigan and New York issued warnings, the agency did not restrict the sale of the fish.

Some warn that dioxin levels in Lake Huron will be exacerbated by a U.S. Army Corps of Engineers navigational dredging project now underway in the Saginaw River.