'Forever chemicals' in freshwater fish more risky than those in drinking water, study says
MILWAUKEE – The levels of "forever chemicals" found in fish harvested from river streams and lakes across the United States, including the Great Lakes, are much higher than in commercially raised fish, according to a new study.
The peer-reviewed study, published in the Environmental Research journal, found that consuming freshwater fish harvested from urban areas 12 times per year could more than triple the level of PFOS – one of the most well-known and researched PFAS compounds – in residents of the U.S.
Researchers say the samples in this study actually show lower levels of some of the chemicals, which could be due to industry changes, but that it's important for the EPA to issue guidance to the public about how to safely consume fish with 'forever chemicals' because they are so prevalent.
What are PFAS, PFOS?
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 the human body over time.
PFOS – or perfluorooctane sulfonate – is part of the PFAS family. The chemical is used in commercial production of textiles, paper, metals, pesticides and firefighting foams, according to the EPA.
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 as well as high blood pressure. The chemicals enter the human body largely through drinking water.
Study shows PFAS in humans come from diet, not just drinking water
The research shows how the compounds found in humans aren't just coming from drinking water, but their diet as well. said Tasha Stoiber, one of the researchers from the Environmental Working Group.
"It's a bit shocking and hard to digest this information," she said. "But the contamination is widespread and it's important to talk about that."
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PFOS levels blow past EPA guidance levels
One serving of locally caught freshwater fish could be equivalent to drinking water with PFOS at 48 parts per trillion for a month, researchers said.
"Finding contaminants in fish isn't new, but talking about PFAS, not a lot of attention has been paid to that," Stoiber said.
Freshwater fishers beware
The study shows that consuming fish harvested from freshwater must now be thought about differently.
"People who consume freshwater fish, especially those who catch and eat fish regularly, are at risk of alarming levels of PFAS in their bodies," David Andrews, an EWG scientist and one of the lead authors of the study, said in a release. "Growing up, I went fishing every week and ate those fish. But now when I see fish, all I think about is PFAS contamination."
Where the fish were harvested
The study was published along with a map (above) showing the locations where the fish in the study were harvested.
In Lake Michigan near Milwaukee, a Coho salmon harvested in 2010 showed 19,000 parts per trillion of PFOS, while a lake trout harvested the same year from Lake Superior near Superior showed 21,000 parts per trillion of PFOS.
The researchers from Duke University and the Environmental Working Group analyzed more than 500 samples of fish filets harvested from across the United States between 2013 and 2015 by the EPA during routine monitoring programs.
Fish with PFAS were found in all 48 continental states.
Great Lakes area of particular concern
All of the 152 fish samples harvested from the Great Lakes had detectable levels of the compounds – raising concerns for the millions of people in the U.S. and Canada who rely on the lakes for drinking water, in addition to harvesting fish.
"These results highlight that PFAS contamination may be of particular concern for the Great Lakes ecosystem and the health of people who depend on fishing on the Great Lakes for sustenance and cultural practices," the report said.
The authors highlighted the particular risk to those who routinely rely on fish they catch from local waters as a major source of protein in their diet.
But, the report noted, there is a lack of guidance on how fish can be safely consumed to protect consumers from PFAS. To remedy that, the EPA should begin issuing advisories and educating the public, researchers said.
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Fish PFOS levels lower than in past, but still concerning
Compared to older fish sampling, the levels of PFOS were actually lower in the 2013 to 2015 data collected for the current study. That decrease is likely the result of industry stopping the use of PFOS and PFOA.
But finding PFAS in fish today is still concerning Stoiber said. Especially because there still isn't an efficient way to remove the compounds from the environment.
"What's needed is a reduction of discharges to the environment, as well as curtailing non-essential uses of PFAS," she said. "There's no practical way to clean surface waters or watershed. We need to reduce the input so that the contamination isn't made worse."
Laura Schulte can be reached at leschulte@jrn.com and on Twitter at @SchulteLaura.
This article originally appeared on Milwaukee Journal Sentinel: Freshwater fish have alarming levels of PFAS 'forever chemicals'
