People should feel free to eat more fish than previously recommended from waters contaminated with mercury and PCBs. But they should also heed new limits on consuming fish contaminated with a former 3M-made industrial chemical. That's the message of the state's latest fish consumption advisory, released Tuesday.

For more than 20 years, the state Department of Health's advisory has helped Minnesotans choose which species of fish to eat and how often in order to minimize their risks from contaminants in fish while gaining the many health benefits from eating fish.

After a former 3M chemical was detected in bluegill sunfish from Lake Calhoun in Minneapolis in 2006, the state began testing fish in metro lakes and rivers for a family of compounds called perfluorochemicals (PFCs).

Based on those results, the advisory indicates that for 14 metro lakes, at least one species of fish -- usually bluegills but also crappies and largemouth bass in some locations -- should be eaten no more than once a month or once a week, depending upon whether the consumer is an adult, child, or expecting a child.

But one fish consumption guideline was eased this year. Previous Health Department guidelines on mercury and PCBs advised consumers that they could choose a fish meal from one of two categories: once per week or once per month.

Now, the state Health Department is advising that it's fine to eat a fish meal from both.

For example, rather than limiting yourself to either a northern pike meal once a week or a sauger meal once a month from Rainy Lake, you can now have both.

"The health benefits of eating more fish are clear," said Pat McCann, an environmental health researcher for the department and coordinator of the fish consumption advisory. "Additional data and a thorough analysis show that this slight change will still be safe for people eating fish."

This year's edition of the advisory includes a substantial amount of new data collected from numerous species of fish from more than 250 Minnesota lakes and rivers.

For this advisory, the department scrutinized lab results from about 4,500 samples of fish tissue, more than twice the usual amount.

Paul Hoff, supervisor of the special studies unit at the Minnesota Pollution Control Agency, said that more advisories based upon the 3M chemicals may be issued in the future. The agency will analyze PFCs in fish from another dozen metro lakes later this summer, he said, and will receive data in a few months about PFC levels detected in fish taken last year from nearly 50 lakes around the state. More fish will be taken and analyzed this summer from the Mississippi River south of the 3M plant in Cottage Grove that manufactured PFCs for decades before ceasing production in 2002, Hoff said.

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