Researchers conducted the first global meta‑analysis of PFAS movement through food webs, reviewing 64 studies and tracing 72 compounds across 100+ terrestrial and aquatic systems. They found some PFAS roughly double in concentration with each trophic level, and identified F‑53B as rising about threefold from prey to predator. The findings raise ecological concerns for apex predators and potential health risks for people who eat contaminated seafood, prompting calls for urgent research and targeted policy action.
How ‘Forever Chemicals’ Climb the Food Chain — And Why That Matters for Our Health
Lead image: William Buelow Gould / Wikimedia Commons
Tiny marine organisms first absorb persistent man‑made chemicals circulating in water, and those compounds can then travel up the food chain — from krill to anchovies to the tuna we buy at the supermarket. New global research shows some of these so‑called “forever chemicals” concentrate as they move from prey to predator, raising alarms for wildlife and people alike.
What Are PFAS?
Per‑ and polyfluoroalkyl substances (PFAS) are a large class of industrial chemicals used across more than 200 types of products because they repel water and resist heat. Their very strong chemical bonds make them highly persistent: PFAS do not readily break down in soil, air or water, and scientists have even detected them in remote regions such as Antarctica.
What the New Study Found
An international team conducted the first global meta‑analysis of PFAS transfer across food webs, compiling data from 64 studies that covered more than 100 terrestrial and aquatic food webs. The researchers tracked 72 PFAS compounds and found that for some substances, concentrations roughly double on average with each step up a trophic level — a pattern driven by uptake rates that exceed an animal’s ability to metabolize or excrete the chemicals.
Not all PFAS behave identically. The study highlights F‑53B, a chemical used in some industrial applications, which showed the largest average increase — about a threefold rise from prey to predator. F‑53B was introduced as a replacement for a restricted compound, but like other substitutes, it can bioaccumulate even more strongly than the original.
“Given what we know about PFAS toxicity from other studies, these extreme accumulation rates in top predators suggest serious health risks,” said Lorenzo Ricolfi, a co‑author and Ph.D. student at the University of New South Wales. “This creates a cascading ecological risk: apex predators face disproportionately high exposure even in relatively low‑contaminated environments.”
Implications for Wildlife and People
Scientists have linked PFAS exposure to a range of human health concerns — including liver and kidney problems and some cancers — though direct causal links are still under investigation. PFAS have been detected in blood samples from people and animals around the world, so increased accumulation in upper trophic levels raises both ecological and human‑health concerns, particularly for species (including humans) that consume predatory fish.
Policy and Research Needs
The authors urge policy attention toward the specific PFAS that concentrate most strongly between prey and predator, especially newer, less‑regulated replacement chemicals. They call for accelerated toxicological research into these alternatives before they become widespread.
Bottom line: The study adds strong evidence that some PFAS magnify up food chains, creating heightened risks for apex predators and potentially for humans who eat contaminated seafood. Policymakers, manufacturers and researchers should prioritize the PFAS compounds that show the highest bioaccumulation and close the gap on knowledge about replacement chemicals.
Originally reported in Nature Communications and featured by Nautilus.
