糖心视频

 Sara Swanson

PFAS levels are declining in Great Lakes fish, new research shows

Decrease Font Size Increase Font Size Text Size Print This Page

Discoveries of PFAS contamination in rivers and lakes throughout Michigan have prompted fish consumption advisories, like this one along the Huron River. Photo credit: Kelly House/Bridge Michigan.

Editor note: This story was originally published by聽Bridge Michigan听(bridgemi.com), a nonprofit and nonpartisan news organization. To get regular coverage from Bridge Michigan, sign up for a free Bridge Michigan newsletter聽听().鈥澛

But in the Journal of Great Lakes Research offers hope that, one day, the fish could be safe to eat again.

The study was conducted by researchers in the former US Environmental Protection Agency Office of Research and Development, which the Trump administration amid a broad push to curtail federal oversight and loosen regulations on a host of chemicals,

Using decades鈥 worth of archived lake trout and walleye samples originally collected to track older pollutants like mercury and PCBs, scientists discovered PFAS levels in Great Lakes fish have declined significantly since the late 2000s, when manufacturers began phasing out once-common compounds like PFOS and PFOA

鈥淭he ecosystem responded very quickly to these changes in industrial production,鈥 said Sarah Balgooyen, a lead author of the study and former EPA chemist who is now a researcher at the Colorado School of Mines.

A growing body of research has linked certain PFAS (an acronym for a class of thousands of chemicals known as per- and polyfluoroalkyl substances) to cancer, thyroid problems and developmental, fertility and immunity challenges.

The research team tested for 45 compounds, using fish taken from the Great Lakes between 1975 and 2020. They found that average contamination levels by 2020 had reached their lowest since the 1980s.

In Lake Erie, for example, PFAS levels in the freeze-dried tissue samples peaked at close to 450 nanograms per gram in 2005 but were closer to 50 nanograms per gram in 2020. In Lake Michigan, levels reached a high of about 150 nanograms per gram in 2010 before drifting down to about 80 nanograms per gram in 2020.

鈥淲e hope to see that trend continue,鈥 Balgooyen said.

That welcome news to Chris Matteson, a 76-year-old from Muskegon who has been fishing in the Great Lakes since the days when factories lined the shore, spewing effluent so foul that, 鈥渋f you could see a foot into the water, that was pretty good.鈥

鈥淚鈥檝e been through a lot of fish warnings,” Matteson said.

A chart showing declining levels of PFAS in Great Lakes fish
Researchers used archived fish tissue to develop a historical record of PFAS levels in Great Lakes trout and walleye, finding that levels have significantly declined since manufacturers began phasing out some PFAS compounds. Photo courtesy of Sarah Balgooyen.

Although PFAS manufacturers their products are toxic since at least the 1970s, the public wouldn鈥檛 learn until decades later. Unregulated use of the so-called 鈥渇orever chemicals鈥 allowed them to escape into the environment, poisoning drinking water and embedding in the bodies of humans, fish and wildlife.

Only in recent years 鈥 after a series of contamination scandals 鈥 have state and federal governments begun regulating PFAS and investigating the extent of the pollution.

In 98 Michigan water bodies, some fish species are that state health officials say it not safe to eat them. Health advisories in hundreds more water bodies call for limiting meals to anywhere from 16 servings a month to six a year.

Michigan Department of Health and Human Services spokesperson Lynn Sutfin said agency staff are reviewing the study.

For now, she said, 鈥渙ur advice for anglers remains the same: To learn how to choose safer fish to eat, follow the Eat Safe Fish Guides.鈥

Gary Ankley, a former EPA research toxicologist and coauthor on the study, said the declining PFAS levels are encouraging. But there is no way to know how low PFAS levels will ultimately fall.

Known as 鈥渇orever chemicals鈥 because they don鈥檛 break down readily in the environment, some amount of PFAS will remain in the lake indefinitely, Ankley predicted.

Balgooyen cautioned that the study offers only a partial picture of PFAS risks in the lakes.

While manufacturers have largely stopped using the so-called 鈥渓ong-chain鈥 PFAS compounds that tend to bioaccumulate in fish, many have switched to new 鈥渟hort-chain鈥 compounds that do not.

The health risks of those newer compounds have not been well-studied.

鈥淲e’re seeing decreases in these compounds that we know are harmful, which is great,鈥 Balgooyen said. 鈥淏ut there’s still this unknown component of the replacement chemicals.鈥

Citing evidence that PFAS is more toxic than previously thought, state and federal regulators in recent years have lowered allowable PFAS levels in drinking water and taken other steps to discourage the chemicals鈥 use.

Seeking to make the EPA more business-friendly, the Trump administration has reversed some of those actions, announcing plans to and for manufacturers to report their PFAS use.

EPA Administrator Lee Zeldin called those “commonsense” changes that would lower costs for industries and water providers while still protecting the public.

But Matteson, the Muskegon fisherman, views the administration loosening of environmental regulations differently.

鈥淭he companies will go back to the easiest, cheapest way to do anything,鈥 he said. 鈥淢ost likely, it isn’t environmentally friendly.鈥

This first appeared on and is republished here under a .

Become a Monthly Patron!

You must be logged in to post a comment Login