How fish scales help reconstruct historical PFAS trends

In recent decades, scientists have documented widespread per- and polyfluoroalkyl substances (PFAS) contamination in the environment, including in fish. Because these compounds don’t degrade easily, fish can accumulate PFAS in their bodies. When people eat these fish, they’re also exposed to the PFAS, some of which can cause adverse health effects.Recent studies have thus used archived samples of fish tissue—typically fillets—to examine the bioaccumulation of PFAS while also monitoring for changes in PFAS composition in these samples. But unlike these muscle tissues, fish scales are “metabolically inert,” according to Lokesh Padhye, who studies emerging environmental contaminants at Stony Brook University. That means any PFAS that bind to the protein-rich scales get trapped and remain preserved for a longer time, he said. At the American Chemical Society Spring 2026 meeting, Padhye made the case for using fish scales to study historical PFAS exposure in these aquatic animals. He presented the preliminary findings at a Division of Environmental Chemistry session on Monday.“This is the only study of its kind that I'm aware of,” said Susan Richardson, an analytical and environmental chemist at the University of South Carolina who attended the talk and wasn’t involved in the work. Focusing on fish scales “could be a really exciting new direction for PFAS work,” she added.For the study, Padhye’s team used striped bass scales collected as part of the Hudson River Biological Monitoring Program—which was one of the longest-running fish monitoring programs in the US. Between 1974 and 2017, scientists surveyed fish populations in the Hudson