Freshwater fish locally caught in the United States contain high levels of dangerous “forever chemicals” that stick around in the environment and can cause health problems in humans, a new study finds.
Compared to their store-bought counterparts, the examined freshwater fish contained 278 times more of these chemicals, called per- and polyfluoroalkyl substances (PFAS), according to the new paper, published Tuesday in Environmental Research.
The team also found that eating one serving of freshwater fish could deliver as much of these chemicals as drinking one month’s worth of water contaminated with PFOS, a particular type of PFAS, at 48 parts per trillion—2,400 times the U.S. Environmental Protection Agency’s recommended limits for safe levels of PFOS in drinking water.
“Even infrequent consumption of, for example, four meals per year [of freshwater fish] could potentially double the amount of PFOS in your body,” Tasha Stoiber, a study co-author and scientist with the Environmental Working Group, an activist organization, tells WBUR’s Gabrielle Emanuel.
These long-lasting toxins are “probably the greatest chemical threat the human race is facing in the 21st century,” Patrick Byrne, an environmental researcher at Liverpool John Moores University in England who did not contribute to the study, tells the Agence France-Presse (AFP). “This study is important because it provides the first evidence for widespread transfer of PFAS directly from fish to humans.”
The researchers examined data from fish collected by the EPA between 2013 and 2015. They detected PFAS in all but one of the 501 samples they tested and also found the chemicals in fish from each of the 48 continental U.S. states.
“To find this level of contamination in fish across the country, even in areas not close to industry where you might expect heavy contamination, is very concerning,” Linda Birnbaum, a toxicologist at the University of North Carolina who did not contribute to the research, tells CNN’s Sandee LaMotte. “These chemicals are everywhere.”
PFAS have been used since the 1940s in products such as food packaging, non-stick pans, clothing and furniture because of their resistance to heat, oil, grease and water. This resistance also means they last a long time in the environment, contaminating soil, drinking water, fish and wildlife, as well as rivers and lakes, according to the Centers for Disease Control and Prevention (CDC).
As a result, the chemicals also make their way into humans. A 2019 CDC report found them in the blood of 98 percent of Americans in the study. PFAS have been linked to health problems including cancer, high cholesterol, thyroid disease and reproductive and developmental harms.
Governments have recently made efforts to reduce the use of PFAS. The FDA phased out the use of PFOS in food packing in 2016, writes Popular Science’s Laura Baisas. Five countries proposed a ban on PFAS to the European Union last week, per the AFP.
Meanwhile, the EPA does not regulate levels of PFAS in fish caught by anglers or sold to consumers, writes the Colorado Sun’s Michael Booth.
“We really need consumption advisories across the country,” Elsie Sunderland, an environmental chemist at Harvard University who did not contribute to the research, tells WBUR.
“What’s needed is a reduction of discharges to the environment, as well as curtailing non-essential uses of PFAS,” Stoiber tells the Milwaukee Journal Sentinel’s Laura Schulte. “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.”
The findings also reveal an environmental justice issue, since several communities in the U.S. catch and consume local fish, the study authors write.
“There are Native American tribes and Burmese immigrants and others who fish because this is who they are,” Birnbaum tells CNN. “This is key to their culture. And you can’t just tell them not to fish.”