You probably know the slick coating on a non-stick pan and the water that beads off a rain jacket. Few people stop to think about what any of that is made from.
The chemicals behind both have a quiet way of sticking around.
They are called PFAS, short for per- and polyfluoroalkyl substances.
Nearly every American now carries measurable amounts in the blood, according to the US Agency for Toxic Substances and Disease Registry (ATSDR), part of the CDC.
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A new overview from the European Food Safety Authority (EFSA) this week pulled together what research has pinned down so far about the health effects. The clearest signal, EFSA said, is a weaker immune response at low doses.
That includes a reduced antibody reaction to childhood vaccines, meaning some kids may build less protection from a given shot.
PFAS are a group of thousands of synthetic chemicals built around a very stable carbon-fluorine bond. They repel grease and water, which is why they end up in cookware, waterproof clothing, firefighting foams, and food packaging.
That same bond is why they resist breaking down in the environment, and in the body.
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What the science has pinned down so far
The CDC's Agency for Toxic Substances and Disease Registry lists several outcomes as potentially associated with PFAS exposure, drawn from years of observational research.
The clearest ones in people include higher cholesterol, changes in liver enzymes, and small decreases in birth weight.
For PFOA, one of the most studied compounds in the family, higher exposure has been linked to kidney cancer and testicular cancer.
Pregnancy-induced high blood pressure and preeclampsia appear in the same list.
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These are statistical associations, not proof that PFAS directly cause each outcome.
There are no approved treatments to clear PFAS from the body, so the focus is on cutting new exposure.
Where does the exposure actually come from?
Drinking water tends to get the most attention. For many people, food is the bigger route.
Eggs and fish can be notable contributors when animals are raised or caught in contaminated areas, EFSA said.
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Grease-resistant food packaging, stain-resistant textiles, some cosmetics, and older non-stick cookware add smaller amounts over time. The exposure is cumulative because the chemicals do not easily leave the body.
The National Academies of Sciences, Engineering, and Medicine recommended in a 2022 report that doctors consider PFAS blood testing for patients with elevated exposure histories.
That includes firefighters, people with occupational exposure, and residents of communities with contaminated water supplies.
What you can actually do about it
At the tap, the US Environmental Protection Agency finalized the first federal drinking-water limits for six PFAS.
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The rule sets 4 parts per trillion for PFOA and PFOS and 10 parts per trillion for three others, including GenX.
Public water systems have until 2029 to meet the limits, with some utilities eligible to request a two-year extension.
The EPA estimates the standards will prevent PFAS exposure in drinking water for about 100 million people.
In May 2026, the EPA proposed to push the PFOA and PFOS deadline out to 2031 for all systems and to rescind the limits on the four other PFAS, including GenX.
Those changes are proposals, not final rules, so the 2024 standards still apply for now.
At home, certified filters that are specifically tested for PFAS removal, such as activated carbon or reverse osmosis units, are the most studied way to cut what comes through the tap.
Switching away from worn non-stick pans and grease-resistant takeout wrappers can trim smaller daily sources.
If you want to know what is in your local tap, public water systems were required to begin PFAS monitoring under the EPA rule, with the first full round of results due by 2027.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.