Are PFAS chemicals accumulating in the seafood you eat?

What's actually in it

PFAS enter waterways from industrial discharge, firefighting foam runoff, and the degradation of PFAS-containing products. Marine organisms absorb them from water, and then larger animals eat the smaller ones, concentrating the PFAS at each step up the food chain.

PFAS don't break down in fish tissue. They accumulate. This is called bioaccumulation, and it's the same reason mercury is a concern in large predatory fish.

What the research says

A 2026 study in Food Chemistry analyzed PFAS co-occurrence, bioaccumulation, and dietary risk from seafood. The researchers found multiple PFAS compounds present simultaneously in most seafood tested, with higher concentrations in species higher on the food chain.

Fatty fish had higher PFAS concentrations because PFAS bind to proteins and fats. Shellfish, particularly bivalves like mussels and clams that filter large volumes of water, also showed elevated levels.

The dietary risk assessment found that for people who eat seafood regularly, fish and shellfish can be a major contributor to total PFAS exposure, comparable to or exceeding other dietary sources. The study recommended varying seafood choices and favoring lower-PFAS options like smaller, shorter-lived fish for frequent consumption.