Can PFAS in tap water affect fertility for multiple generations?

What's actually in it

PFAS (per- and polyfluoroalkyl substances) are in tap water across the country. They get there from firefighting foam, industrial runoff, and consumer products that break down in landfills. Standard water filters remove some, but many types of PFAS pass right through. These chemicals don't break down in nature or in your body, which is why they're called "forever chemicals."

What the research says

A 2026 study in Environ Res gave mice drinking water containing PFAS at levels similar to what's found in contaminated tap water. Then the researchers tracked what happened to their offspring, and their offspring's offspring, across three generations.

The results were alarming. Even at trace levels, PFAS damaged mitochondria in embryos. Mitochondria are the energy factories inside every cell, and embryos need them working perfectly to develop normally. The damage showed up not just in the mice who drank the water, but in their grandchildren, who were never directly exposed.

The embryos from exposed lineages had lower energy production, more oxidative stress, and poorer development overall. The effect got passed down through changes to the egg cells, meaning the chemical exposure altered something fundamental about how the next generation's cells function.

This study matters because the PFAS concentrations used were realistic. They weren't extreme lab doses. They were the kind of levels that show up in regular tap water in many communities.