Study of invasive mussels finds PFAS is nearly everywhere in the Great Lakes

• ‘Forever chemicals’ were found in mussel tissues at 106 out of 120 sampling sites across the Great Lakes
• The highest average PFAS concentration was in Lake Michigan mussels, followed by the Niagara River, Lake Erie, Lake Ontario and the Detroit River
• Newer PFAS alternatives in the lakes represent an ‘impending storm,’ one researcher said.

Every summer throughout the mid 2010s, researchers scoured the Great Lakes in search of PFAS contamination.

They took tissue samples from invasive mussels that have spread across the lakes near wastewater treatment plants, in rivers feeding into the lakes and from sites further offshore. They took samples from 120 sites in total.

The results: The scientists found PFAS nearly everywhere.

Those findings — published late last year by researchers at the National Oceanic and Atmospheric Administration and the National Centers for Coastal Ocean Sciences — are another indicator of how ubiquitous so-called “forever chemicals” have become in the environment. PFAS, or per- and polyfluoroalkyl substances, have been linked to cancer, thyroid problems and other health challenges.

While scientists have documented the substances in organisms near the bottom of the food chain, like mussels, before, this report provides the clearest picture yet of the magnitude and spatial distribution of the toxic compounds in the lakes. 

The report combined data from various studies in the Great Lakes under the National Mussel Watch Program, which has tracked contaminants in the lakes since 1992. The program didn’t start tracking PFAS, however, until 2013.

Mussels in Lake Michigan had the highest average concentration of PFAS, followed by sites sampled in the Niagara River, Lake Erie, Lake Ontario and the Detroit River.

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Newer PFAS compounds meant to replace phased-out chemicals in manufacturing are appearing in greater numbers and could reach harmful levels sometime soon, the report found. Although these so-called “short-chained” compounds aren’t as heavily regulated as other PFAS, some evidence suggests they can persist in the environment for longer.

“There is an impending storm of these short-chained components,” said Michael Edwards, a physical scientist at NOAA and one of the report’s authors. “Now there’s a need to be ahead of that storm, to do more monitoring, to do more assessments.”

The results have worrying implications for the Great Lakes, which hold 21% of the world’s surface freshwater, support a $7 billion dollar fishing industry and provide drinking water for more than 30 million people. 

PFAS compounds have many channels to enter the environment. They are found in a wide array of products, ranging from nonstick cookware and stain-resistant carpet to firefighting foam and automobiles. Past research shows that much of the contamination is literally raining down on the Great Lakes.

The researchers also found PFAS in mussels sampled from undeveloped areas, although the highest levels were detected adjacent to developed land and industry. Contamination wasn’t as high near municipal wastewater treatment plants which are required to limit discharge of some types of PFAS.

A spokesperson for the Department of Environment, Great Lakes, and Energy told Bridge Michigan that, although the agency has detected PFAS in the Great Lakes, no water supply relying on them has been out of compliance with Michigan’s PFAS limit since they went into effect in August 2020.

However, more work needs to be done by the state to encourage industry to find safe alternatives to PFAS in manufacturing, said Erica Bloom, toxic campaigns director at the Ann Arbor-based Ecology Center. 

Bloom added that contamination in the Great Lakes rarely stays contained in their waters. PFAS-concentrated white foam has been washing up on the shores of the Great Lakes in recent years and forms in inland lakes, rivers and streams across the state. Earlier this week, Michigan also tripled the number of waterbodies where it says fish are no longer safe to eat due to PFAS contamination.

Tony Spaniola, who owns a home in the PFAS-polluted community of Oscoda and co-chairs the Great Lakes PFAS Action Network, said he wishes EGLE would do more about contamination in Lake Huron, though recognized that the agency is stretched thin addressing such widespread contamination.

Oscoda residents struggled to grab EGLE’s attention about the beach foam, eventually conducting their own tests that showed high levels of PFAS.

 It’s likely that any community dealing with a similar problem, Spaniola said, would need to be vocal about the contamination in their community. “People in the community have to make their voices heard with the agency to let them know they have a problem,” he said.