Forever chemicals found in most tested fish from these 4 IL rivers

CHAMPAIGN, Ill. (WCIA) — A team of University of Illinois researchers studied four northern Illinois rivers, in which nearly all fish across nine tested species were found with “ forever chemicals .”

Forever chemicals, known more formally as per- or polyfluoroalkyl substances (PFAS), are synthetic chemicals that can be harmful to the health of people, animals, and the environment. These are found in everyday products and have even made their way into drinking water , soil, and human tissues. The Environmental Protection Agency estimates that nearly 15,000 PFAS exist today.

The research team, headed by U of I Professor of Bioengineering Joseph Irudayaraj, found PFAS in all 15 of their northern Illinois test sites. High levels of one type of PFAS compound — perfluorooctanesulfonic acids (PFOS) — were found in almost all the fish studied.

In an interview with the U of I News Bureau, Irudayaraj said PFAS contain carbon-fluorine bonds, which is one of the strongest bonds in organic chemistry. These are very hard to break down, giving PFAS long-lasting durability. This is why they are dubbed “forever chemicals” and can be bad for your health, as they gradually build up in the body and stay there.

“About 99% of people living in the U.S. have PFAS in their system,” Irudayaraj said .

So, why do industrial and commercial industries continue to use them in their products? PFAS are resistant to heat and water and remain stable under such stresses. Long-chain PFAS — which possess at least six carbon-fluorine bonds — was often utilized before people became aware of the dangers of forever chemicals.

Now, short-chain PFAS — with less than six of these bonds — are usually used instead. Irudayaraj said it was theorized that short-chain PFAS would be less impervious and therefore less destructive. However, that is not quite true, as Irudayaraj and his team soon found.

As industrial emissions and urban rainwater may worsen PFAS contamination, they wanted to focus on waterways near Chicago. Specifically, the researchers analyzed fish in the Pecatonica River, Rock River, Sugar River and Yellow Creek from 2021-2022.

Nine fish species spanning different castes of the food chain were represented in the study. That includes bluegill, channel catfish, common carp, northern pike, smallmouth bass and walleye. They were then scanned for the presence of 17 PFAS chemicals.

Channel catfish were the most susceptible to PFAS accumulation. This species is omnivorous but at the top of the food chain, being the lowest in plant-eating. Fish from every sampling site had PFOS, which is a long-chain PFAS. Short-chain PFAS were also found.

As for location, Rock River fish had the most PFAS build-up in their tissues, though Irudayaraj noted that fish travel, so this does not necessarily mean the river itself is highly contaminated. It does, however, mean that a risk of forever chemicals is posed to those who have consumed fish from these test sites or spent time in their waters.

“Further studies are warranted to comprehensively evaluate the occurrence and sources of PFAS throughout the state of Illinois,” the researchers wrote in their study, which is now published in the Science of the Total Environment journal. “Such information is crucial to better understand the distribution and potential risks of these compounds to the environment.”

Due to elevated levels of PFAS in some Illinois waters, the Illinois Department of Public Health recently updated their Fish Consumption Advisory lists. To learn more, click here .

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