PFAS 'ubiquitous' in water, atmosphere in Great Lakes Basin

A first-of-its-kind study published this week shows that levels of toxic per- and polyfluoroalkyl substances, or PFAS, are now so ubiquitous in the environment that they have begun building up in the Great Lakes Basin after entering it through rainwater and the air, contaminating 95% of the United States' fresh surface water supply.

Researchers at Indiana University, Bloomington and Environment and Climate Change Canada published the study Thursday, revealing that "background levels" of PFAS, also called "forever chemicals," are so high that atmospheric counts were consistent throughout the basin.

"The PFAS in rain could be carried from local sources, or have traveled long distances from other regions. Regardless, it is a major source of pollution that contributes to the lakes' levels," reported The Guardian on Saturday.

The levels of PFAS in precipitation did not correlate with whether or not an area in the Great Lakes Basin was heavily industrialized, lead author Chunjie Xia, a postdoctoral associate at Indiana University, told The Hill.

"The levels in precipitation don't depend on the population," said Xia. "They are similar in Chicago, which is heavily populated, and at Eagle Harbor, Michigan, where there's maybe 500 people living in a 25-kilometer radius."

"That tells us the levels are ubiquitous," he said. "This is the first time we've seen that. We've never seen that for other pollutants before."

Within the basin, however, levels of PFAS were higher near urban areas.

Twenty percent of the world's freshwater is held in the Great Lakes Basin, while 10% of the U.S. population and 35% of Canadians live in the region.

In 2023, Duke University and the Environmental Working Group analyzed fish samples collected from the Environmental Protection Agency's monitoring program for the Great Lakes, and found that eating just one locally caught freshwater fish could be the equivalent of drinking PFAS-contaminated water for a month.

Forever chemicals have earned their nickname because they do not naturally break down and can continuously remain in and move through the environment. PFAS are used by dozens of industries to make products heat-, water-, and stain-resistant.

European lawmakers have proposed a ban that could go into effect as early as 2026, but Reutersreported Wednesday that the law could include exemptions for certain industries.

Last month, the Biden administration finalized a rule setting limits on PFAS in drinking water.

"We need to take a broad approach to control sources that release PFAS into the atmosphere and into bodies of water," Marta Venier, a co-author of the new study, toldThe Guardian, "since they eventually all end up in the lakes."