New research from the University of Notre Dame shows how PFAS chemicals move through the Great Lakes ecosystem and into people. The peer-reviewed study, published this spring, analyzed 42 years of data from nearly 2,500 samples across the food web.
Researchers combined studies on algae, fish, birds, and other organisms to track six common PFAS compounds. Levels of PFOS declined sharply in Lakes Erie and Ontario after industries voluntarily phased out the chemical in the early 2000s. No similar drop appeared in the larger upper lakes, where water remains for decades longer.
Gary Lamberti, an aquatic science professor at Notre Dame and study co-author, said the food web itself transfers the chemicals between organisms. The study confirmed that concentrations rise at higher trophic levels, with predators such as salmon and eagles showing the highest amounts.
State officials in Michigan and elsewhere already issue fish consumption guidelines because of PFAS risks. Katherine Manz of the University of Michigan noted that better data on levels in the food web can improve public health advice.
Lamberti added that removing these chemicals from production allows food webs to cycle them out over time, offering a path for future management.
