Bioaccumulation
The gradual buildup of PFAS in living organisms over time, faster than they can be eliminated.
Bioaccumulation occurs when organisms absorb PFAS faster than they metabolize or excrete them. PFAS accumulate primarily in blood, liver, and kidneys. Long-chain PFAS like PFOA and PFOS have human half-lives of 3-8 years. Bioaccumulation through the food chain (biomagnification) means top predators — including humans — carry the highest body burdens.