Chemical used by 3M found in fish; advisory issued

A chemical once manufactured by 3M has shown up in fish from several east metro lakes, prompting the Minnesota Department of Health to warn people to limit the fish they eat from those waters.

By Mary Lynn Smith, Star Tribune

Last update: August 16, 2007 - 11:21 PM

A chemical once manufactured by 3M has shown up in fish from several east metro lakes, prompting the Minnesota Department of Health to warn people to limit the fish they eat from those waters.

The results are part of a broader study to help state officials figure out the extent of the contamination after the chemical PFSOS (perfluorooctane sulfonate) was found earlier this year in bluegills taken from Lake Calhoun in south Minneapolis. Scientists were baffled by the finding because the lake is nowhere near the former 3M dump sites in the east metro that have contaminated groundwater and raised concerns about drinking water safety.

The new fish advisories in Ramsey County are for Como and a chain of lakes including Phalen, Gervais, Gervais Mill Pond, Round, Keller, Kohlman and Spoon. In Washington County, the new fish advisories are in effect for Demontreville, Olson, Lake Elmo and Ravine lakes.

Health officials said the chemical levels don't likely pose a health risk for swimmers.

They have found no traces of several related 3M chemicals in drinking water in Minneapolis and St. Paul.

Fish from Bald Eagle, White Bear and Square lakes also were tested but the chemical level either wasn't detected or was a low enough level not to prompt a restrictive advisory.

In some studies, the chemical has been shown to cause cancer, liver and thyroid problems in animals, but no adverse health effects have been found in humans.

The fish advisories are based on potential risks from years of consumption. Health officials said there have been no reports of illness from people who've eaten the fish containing PFOS.

"As we get more fish from more lakes, we're hoping to see some patterns and track down the causes," said Paul Hoff, who's supervising the study for the Minnesota Pollution Control Agency. "We want to find the source and cut it off."

Fish from at least 20 more lakes in Minneapolis and the west metro area will be tested in the next few months, Hoff said.

The results so far show that contamination in Lake Calhoun isn't unique, although the chemical's level in fish there was among the highest tested so far, Hoff said.

"This tells us that there's something more going on here," he said.

The source of the chemical in these lakes isn't known yet, Hoff said. But he said it's possible that the contamination in the fish from Lake Elmo could be related to the nearby 3M waste disposal sites.

3M spokesman Bill Nelson said more data are needed before that determination can be made.

Nelson said the recent findings of elevated chemical levels in the metro lakes supports the decision by 3M to phase out the manufacture of PFOS. The company began manufacturing the chemical in the 1950s and stopped in 2002.

"3M had information that PFOS was found at low levels all over the world and that these materials don't break down naturally in the environment," Nelson said. "They can last for a long time and, based on that information as well low levels being found in the blood of the general population, 3M for environmental responsibility reasons, stopped manufacturing it."

Mary Lynn Smith • 612-673-4788

Mary Lynn Smith • mlsmith@startribune.com