PFAS have been found in animals in Wisconsin. Here's what you should know

An adult bald eagle feeds its eaglet in June 2023 at a nest in Racine County.

MADISON - As research on toxic "forever chemicals" continues, more is being learned about not only the impacts on humans, but on animals as well.

Here's what you should know about the research in Wisconsin on that topic.

Have PFAS been found in animals in Wisconsin?


Sean Strom, a wildlife toxicologist for the Department of Natural Resources, said that PFAS have been detected in a number of species in Wisconsin, including bald eagles, fish, deer, white-footed shrews, mice, muskrats and mink.

More: 'Forever chemicals' in Great Lakes fish more risky than PFAS in drinking water, study says

What kind of impacts do the chemicals have on animals?

Just like in humans, it's really hard to pinpoint what problems PFAS cause in animals, and what impacts are caused by other environmental factors, Strom said.

"Any of the impacts are going to be referred to as sub-lethal or subtle," he said. "And that makes it even more difficult to observe and document."

But it's likely that PFAS will have similar impacts to those observed in humans, such as reproductive issues, thyroid problems or cancer.

What do human studies show about the impacts on animals?

Researchers from the Environmental Working Group in a study released Tuesday found that PFAS impacts on humans can be used to gauge the impact on wildlife, as well.

"There's a much smaller body of research on how these chemicals are impacting the health of wildlife, and part of that is the difficulty of studying health impacts in wildlife populations not in a laboratory setting," said David Andrews, one of the researchers on the study.

"And we think this human health data, and our understanding of how it causes harm should be used as a way to evaluate the potential impacts on wildlife."

Do PFAS affect certain animals more than others?

Research shows that pretty much all animals are susceptible to PFAS, but it's unclear if some species will be more impacted in the long run than others, said Tasha Stoiber, an EWG researcher.

For the most part, animals that live close to humans or in the water are being found to have higher levels of PFAS, because they are more often exposed to higher levels.

"Animals that live near known sources of PFAS have higher rates, definitely those animals are going to be more susceptible," she said.

More: 'Forever chemicals' found in Wisconsin River, lakes near Stella, raising concerns over fish

Should hunters be worried? And what about anglers?

For hunters, the worry over contaminated deer is small, Strom said.

There is an advisory for deer harvested near the Tyco Fire Products facility in Marinette, which says hunters shouldn't consume the livers from the animals. But other than that, there shouldn't be concerns for animals harvested where there aren't high levels of contamination.

"This is a site-specific concern," Strom said.

But those who hunt waterfowl or fish regularly may want to check consumption advisories, or if PFAS testing has been done on the water they're harvesting from. Because waterfowl spend a lot of time in the water and consume fish there could be more cause for concern. Testing for PFAS in waterfowl is underway in Wisconsin, and results are expected sometime in 2024, Strom said.

As for anglers, checking for any fish consumption advisories is always a good idea. Consuming fish with high levels of PFAS can be just as bad, if not worse, than drinking contaminated water, so use caution in eating too many fish harvested from contaminated lakes, rivers or streams.

More: Fish may carry higher levels of PFAS than drinking water. Here's what you should know about it.

How do we prevent PFAS from getting into animals?

In short, the easiest way to prevent PFAS from getting into animals is to prevent them from getting into the environment at all.

Stoiber said that the best way to keep PFAS from affecting animals is to stop the chemicals from entering the environment in the first place.

"The time to act is now, and those actions will benefit human health, of course, and the health of wildlife," she said. "We really need to advocate for getting rid of non-essential uses of PFAS, and the best strategy is to turn off the tap."

More: ‘Forever chemicals’ are a growing problem. Here’s what we found when we tested Wisconsin’s drinking water.

What do I need to know about PFAS?

PFAS, or per- and polyfluoroalkyl substances, are a family of man-made chemicals used for their water- and stain-resistant qualities in products like clothing and carpet, nonstick cookware, packaging and firefighting foam.

The family includes 5,000 compounds, which are persistent, remaining both in the environment and human body over time. The chemicals have been linked to types of kidney and testicular cancers, lower birth weights, harm to immune and reproductive systems, altered hormone regulation and altered thyroid hormones.

The chemicals enter the human body largely through drinking water. PFAS have been found across Wisconsin.

Laura Schulte can be reached at and on X at @SchulteLaura.

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This article originally appeared on Milwaukee Journal Sentinel: Here's what you should know about 'forever chemicals' in animals