Lee Bergquist

Milwaukee Journal Sentinel

Wisconsin officials are using fish to locate a class of pollutants under growing national scrutiny, but aren’t following Michigan’s lead, where white-tailed deer have also been sampled to identify potential hotspots.

The aim, in either case, is to identify areas with high concentrations of perfluorinated chemicals, a class of contaminants that do not easily deteriorate and have been linked to illnesses ranging from some cancers to developmental problems in fetuses.

In Wisconsin, scientists have identified numerous waterways where the chemicals, which have been in wide use for decades, have been found. The highest levels detected have been in sections of the Mississippi River.

Since 2007, the Wisconsin Department of Natural Resources and Department of Health Services have recommended, for example, no more than one meal a week of bluegill and crappie for one of the chemicals, perfluorooctane sulfonic acid, or PFOS, on the Mississippi.

But in the past year, regulators are paying special attention to Marinette in northeastern Wisconsin.

There, the chemicals have spread from a property of Tyco Fire Products into groundwater, local streams and some private wells.

Tyco, a unit of Johnson Controls, manufactures firefighting foam, which contains PFOS. Tyco is determining the extent of contamination and will be required to clean it up. The company has also installed water filtration systems on 37 properties that rely on private wells, and as a first step, will place treatment systems in two waterways to remove the chemicals now flowing into Green Bay.

RELATED:New evidence of groundwater pollution turning up near Lake Michigan at Tyco plant in Marinette

RELATED:DNR: Do not eat deer taken near contaminated former Wurtsmith base

Michigan warning on venison

On Oct. 19, Michigan issued a “Do Not Eat” advisory for venison for an area within five miles of a marsh that borders the former Wurtsmith Air Force base near Lake Huron after a single deer showed high levels of a chemical ingredient in firefighting foam.

Michigan authorities have identified numerous areas around the state where the chemicals have been found and decided to test deer near the military base after hunters expressed concerns about the safety of venison.

Of 20 deer tested to date, one showed high levels of PFOS. No other chemicals turned up in the other deer, or at very low levels, according to Michigan authorities.

In a statement, the Michigan departments of natural resources and health said their work targeting deer was “the first of its kind and very little scientific information exists on whitetail and (perfluorinated chemicals.)”

In Wisconsin, Marinette Police Chief John Mabry said the DNR told his office that the agency “would be happy” to test deer his officers killed as part of a state program that allows communities to apply for grants to pay sharpshooters to reduce urban deer populations.

DNR officials said they have no knowledge of such an offer.

Venison donated to food pantries

Douglas Oitzinger, who served two terms as Marinette's mayor, the last ending in 2006, also has pressed officials in Madison to test deer because venison is donated to food pantries.

“The point is that we have an opportunity here,” Oitzinger said. “We give that venison to poor people. The deer are drinking water out of the creeks.”

The current mayor, Steve Genisot, said, “this is all kind of new, but we would have no problem with them testing deer.”

RELATED:Firefighting foam used by unit of Johnson Controls poses toxic threat to Green Bay

Chemicals tied to health problems

A federal report released in June 2018 found that perfluorinated chemicals present a greater public health risk than previously known.

The report said epidemiology studies suggest that the chemicals are associated with increased risk of pregnancy-induced hypertension, liver damage, thyroid disease, asthma, decreased fertility, some cancers and a decline in response to vaccines.

But officials at both the DNR and the Department of Health Services said there are no current plans to sample deer.

In an email, Rob Thiboldeaux, a toxicologist for health services, said Michigan’s initiative with deer appears to be the first of its kind. Duplicating the work would be difficult, and he said Wisconsin is "not yet set up for this specific type of work."

Eric Lobner, the DNR’s director of wildlife management, said fish are better indicators of contamination.

“You’ll get better test results,” Lobner said. “You are working with a species that is literally in the water.

“This is standard scientific procedure. You look at your levels of risk as you progress through the food chain and in this case you expect that the highest concentrations would be in water.”

If levels of contamination are high in fish, then the next move is to investigate other species, such as deer or geese, he said.

Fish surveys involving perfluorinated chemicals date back to 2006 in Wisconsin.

The DNR said that preliminary results of 43 fish taken from the Menominee River and Green Bay in 2017 and 2018 showed that perfluorinated chemicals were present in the fish. More sampling will take place this year in Marinette “near known or probable sources” of the chemicals, Sean Strom, a DNR toxicologist, said in an email.

The results from 2017 and 2018 were about the same as levels found in past surveys, Strom said. The fish consumption advisory for another pollutant — polychlorinated biphenyls, an industrial chemical that was banned by regulators in the 1970s and has also been found in the waters — is more restrictive, and if followed, should protect the public, he said.

As the chemicals and their health effects have come under increased scrutiny, the DNR asked DHS in March 2018 to recommend safe levels that could be present in groundwater. The recommendations would then go through a multiyear rule-making process.

Thiboldeaux said his agency is assessing 26 chemicals.

Some chemicals have been assigned to a single expert, and in the case of PFOS, and another fire retardant, PFOA, perfluorooctanoic acid, he said a group of environmental scientists is reviewing the relevant scientific literature to make recommendations.

He declined to provide a date on when the agency would make recommendations.