State health officials say fish tested from nine of Minnesota's 10 largest walleye lakes show those lakes have very little or no contamination from perfluorochemicals, or PFCs.
The classes of chemicals were used to make products that resist oil, stains and grease. Animal testing shows PFCs can harm the liver and thyroid.
Pat McCann, a research scientist with the Minnesota Department of Health, said the lack of PFCs means state consumption recommendations won't change for PFCs in those lakes.
"We didn't find PFCs, which is good. We have found them in some metro area lakes and also in a few lakes by Duluth and one lake in southern Minnesota," McCann said. "In general, lakes outside the metro area have been low or non-detect as far as levels of PFCs in fish."
McCann said the lack of PFCs in the state's most popular walleye fishing lakes is good news, but he said that it wasn't a surprise because the health department has data on about 50 lakes that are outside the metro area that showed lower levels.
The lakes tested included Kabetogema, Rainy, Vermillion, Mille Lacs, Lake of the Woods, Leech, Winnibigoshish, Cass and Upper Red Lake.