New research traces how ‘forever chemicals’ move through the Great Lakes and into people

New research from the University of Notre Dame looked at how PFAS, the "forever chemicals" found in nonstick cookware, cosmetics, and food packaging, move through the Great Lakes and up into the animals and people who eat from them. Researchers combined 42 years of studies and nearly 2,500 samples of algae, fish, and birds to track the chemicals through the food chain. They found PFAS build up more the higher you go: algae and plants have the least, while predators like salmon and eagles, which eat a lot of contaminated prey, carry the most.

There was some good news. One PFAS chemical called PFOS has dropped sharply in Lake Erie and Lake Ontario over the last two decades, following a voluntary phaseout by industry in the early 2000s. That drop was much smaller in Lakes Superior, Michigan, and Huron, likely because water sits in those larger lakes far longer, sometimes 60 to 170 years, compared to just 2 to 7 years in the lower lakes. The finding suggests that once these chemicals stop being made, they do eventually work their way out of the environment, though slowly.

This matters most directly if you eat fish from the Great Lakes region. Several states, including Michigan, Wisconsin, Pennsylvania, Montana, and North Carolina, issue advisories on how much locally caught fish is safe to eat because of PFAS levels. Michigan has tested Great Lakes fish for these chemicals since 2012 and updates its guidance yearly. There's no nationwide ban on PFAS, but some restrictions and voluntary industry phaseouts are already in place.