Eh Mwee still remembers a fish he received over a decade ago, and—more importantly—where it came from.
Mwee, who is of Karen ethnicity and was born in Burma (now Myanmar), was 29 years old and had just arrived in Syracuse, New York, after spending 25 years in a Thai refugee camp. Food was scarce in the camp. Mwee was accustomed to eating what he could find. So when a fellow Karen refugee offered him a fish from nearby Onondaga Lake, a Superfund site that butts up against several polluting factories, he gladly accepted. “I didn’t believe anything about poison. ‘Come on, a fish is fish,’” he recalls thinking.
But his meal came from waters contaminated with industrial pollutants—including those known as per- and polyfluoroalkyl substances (PFAS) or “forever chemicals,” which have been linked to health conditions, such as cancers and impaired immune function.
Htoo Say prepares to fish in the Oswego River in New York.
PFAS are infamous for contaminating drinking water. But a growing number of studies suggest that we may also consume concerning quantities of these chemicals through food—especially fish.
Earlier this year, New York State Department of Health (NYSDOH) scientists published a study finding that refugees from Burma living in the Syracuse area had elevated PFAS concentrations in their blood. Locally caught fish may be the source.
But the full extent of PFAS contamination in fish—whether from a fishing hole or supermarket counter—is not yet known. U.S. Food and Drug Administration (FDA) and Environmental Protection Agency (EPA) studies are ongoing, and researchers are still working out how best to quantify PFAS in fish, as even exceedingly low levels are now believed to threaten human health.
One concern is clear: Communities that rely on locally caught fish as a key component of their diet and culture may face the greatest risk.
Awash with PFAS
But PFAS molecules contain carbon-fluorine bonds so strong that, once created, these “forever chemicals” do not easily break down in the environment. PFAS are increasingly showing up in food, such as beef in Michigan and produce in Maine, due to soil fertilized with contaminated wastewater sludge.
Fish are also a concern, says Heidi Pickard, a PhD candidate at Harvard University who studies PFAS in aquatic ecosystems. “The same way that [PFAS] can get into the drinking water, they can get into the surface waters and a lot of these chemicals then can accumulate into the fish.”
A 2017 study drawing on data from the Centers for Disease Control and Prevention’s (CDC) National Health and Nutrition Examination Survey showed that Americans who ate more fish and shellfish had greater PFAS concentrations in their blood than those who did not.
“The same way that [PFAS] can get into the drinking water, they can get into the surface waters and a lot of these chemicals then can accumulate into the fish.”
The EPA has been testing for PFAS in fish from select rivers since 2008 and from the Great Lakes since 2010. “In the majority of our studies we have found low levels of perfluorooctane sulfonate (PFOS) in nearly all of the fish tissue tested, and five additional PFAS chemicals that are often found with the PFOS in fish but are less likely to be detected in ambient or drinking water,” said an EPA spokesperson in a statement to Civil Eats.
As part of their Total Diet Study (TDS), the FDA has tested for PFAS in food since 2019—including in fish from supermarket counters. They’ve detected PFAS in fish sticks and canned tuna, as well as tilapia, cod, and shrimp. But their stance is that, “Based on the best available current science, the FDA has no scientific evidence that the levels of PFAS found in the TDS samples tested to date indicate a need to avoid any particular food.”
Elsie Sunderland, an environmental chemist at Harvard University, questions that messaging. “The big issue I have is how that limited set of data has been interpreted and communicated to the public,” she says, noting that standard PFAS analyses only capture a limited number of these chemicals. There are now over 9,000 PFAS; the FDA’s most recent analysis included only 20.
Sunderland also worries that standard analytical tools are not yet sensitive enough to capture PFAS concentrations in food at levels that could potentially impact human health when multiplied by many meals. “Quantifying the concentrations at low levels is hard,” says Sunderland. “But it turns out that that is what we need to do because people eat a lot of certain things.”
Because of their diets, subsistence fishers can be at risk of increased exposure to a range of environmental pollutants. “If someone eats 10 times more fish, they are going to have 10 times more exposure to whatever is in that fish,” says Jeremy FiveCrows, communications director for the Columbia River Inter-Tribal Fish Commission (CRITFC) and a member of the Idaho-based Nez Perce Tribe. In the early 1990s the commission conducted a survey of tribal members’ fish eating habits. The study revealed that they ate 6 to 11 times more fish than the general U.S. population, which at the time ate 6.5 grams per day.