GRAND RAPIDS, Mich. (WOOD) — A new study by the Environmental Working Group has found another troubling source of PFAS contamination: freshwater fish.

The study, which will be published in the March edition of the scientific journal Environmental Research, found that a single serving of freshwater fish contains an average of 48 parts per trillion of the “forever chemicals.” That equates to drinking roughly a month’s worth of PFAS-tainted water.

Scott Faber, EWG’s senior vice president for government affairs, called the test results “breathtaking” and said it shows how pervasive PFAS pollution truly is. Nadia Barbo, a graduate student at Duke University and lead researcher on the project, called the results “staggering.”

“(Based on the findings) there should be a single health protective fish consumption advisory for freshwater fish across the country,” Barbo said in a release.

The PFAS level in self-caught fish is notably higher than fish sold in grocery stores and markets across the country, which are tested by the Food and Drug Administration. Researchers say this will have a disproportionate impact on communities in need that rely on self-caught fish for food.

“Self-caught fish are an important source of subsistence for many individuals, indicating that advisories for PFAS will disproportionately affect these individuals who cannot afford to replace self-caught fish with purchased fish,” the study concluded.

The data analyzed 501 fish samples from across the country. Some form of PFAS was found in 500 of them. Most fish samples had concentrations of total PFAS between 1,000 and 10,000 nanograms per kilogram, which is equivalent to 1,000 to 10,000 parts per trillion as measured in liquid. For reference, the maximum containment levels in Michigan for the most common types of PFAS in drinking water range from 6 to 16 ppt.

The median level of total PFAS found in the fish fillets was 9,500 ng/kg. For the Great Lakes, the median level was even higher: 11,800 ng/kg.

Note: Highest example of PFAS found in one fish. The PFAS rate does not apply to the entire species.

Of the 501 samples, 152 were pulled from the Great Lakes. On average, Lake Erie and Lake Ontario showed fish with the highest amounts of PFAS. The most polluted fish was a yellow perch pulled from Lake Erie that contained 74,900 ng/kg of PFAS. Lake Ontario had three fish with more than 60,000 ng/kg of PFAS. A lake trout from Lake Huron registered at 67,490 ng/kg.

Numbers were lower in the fish samples from Lake Michigan and Lake Superior. The most polluted fish from Lake Michigan was a longnose sucker caught off the coast of Leelanau County that contained 43,880 ng/kg of PFAS. The most polluted fish in Lake Superior was also a longnose sucker, this one containing 37,730 ng/kg caught off the coast of Ontonagon County.

EQG senior scientist Tasha Stoiber said the findings not only show how widespread PFAS pollution is but also how the chemicals move in a cycle and end up in our bodies.

“PFAS do not disappear when products are thrown or flushed away. Our research shows that the most common disposal methods may end up leading to further environmental pollution,” Stoiber said. “Identifying sources of PFAS exposure is an urgent public health priority.”

PFAS — or per- and polyfluoroalkyl substances — is a giant group of chemical compounds. They were first developed by DuPont in the 1940s and incorporated into thousands of products in the years that followed ranging from Teflon to firefighting foam. In the Grand Rapids area, contamination has often been blamed on the Scotchgard used to waterproof Wolverine Worldwide shoes.

There is evidence that DuPont discovered PFAS was toxic as early the 1950s, including that the chemicals do not break down naturally and can build up in the human body. That evidence, however, was kept in house and the chemicals were created and used for decades.

It wasn’t until 2005 that the Environmental Protections Agency identified PFAS as a pollutant and labeled it a major health risk. According to the Centers for Disease Control and Prevention, PFAS can cause reproduction issues, suppress a person’s immune system and increase the risk for certain cancers.

Faber said that besides the need for more awareness on PFAS pollution in freshwater fish, the study underscores the need for the EPA to take quick action.

“The EPA needs to move swiftly to set regulations for the industries most likely to be dumping PFAS into the environment. Downstream communities especially have suffered the consequences of unregulated PFAS discharges for far too long,” Faber said.

A spokesperson for the Michigan Department of Health and Human Services encouraged people to follow the Eat Safe Fish Guides that are updated annually by the state. The guidelines break down which limits anglers should follow based on fish species, where it was caught, and which pollutant is the problem.

The MDHHS will review the EWG study but “ensures that Eat Safe Fish guidelines are based on the best available science to be health protective for people who eat fish caught in Michigan.”