Perfluoroalkyl and polyfuoralkyl substances (PFAS) are a group of at least 14,000 man-made chemicals that have been used in industry and consumer products worldwide since the 1950s. Perfluorooctanoic acid (PFOA) was initially used to manufacture nuclear weapons during World War II. Since then, manufacturers have used PFAS in a wide range of products because they repel oil and water, reduce friction, and resist temperature changes. DuPont used them for its Teflon nonstick pans and 3M for its Scotchgard stain-proofing spray. Today, PFAS are most commonly found in food packaging, water and stain repellent fabrics, cosmetics, nonstick cookware, and fire-fighting foam.
PFAS have leaked into the environment from manufacturing plants, military bases, airports, and landfills. Factories emit them from smokestacks or waste. Military bases and airports have long used PFAS firefighting foams for training and emergencies. The compounds seep through the filtration systems at many landfills and wastewater treatment plants. Some treatment plants sell sewage sludge for fertilizer, which contaminates soil and crops. People may absorb small amounts of PFAS from cookware, cosmetics, or dental floss.
The soil, surface water and groundwater of neighboring ecosystems have been contaminated. When PFAS enter the environment, they bioaccumulate in fish, wildlife, livestock, and people. The concentration of PFAS in freshwater fish is thousands of times higher than what’s typically found in drinking water. The Environment Working Group has reported that just one serving of fish can be equivalent to a month of drinking contaminated water.
At least 17 states have issued PFAS-related fish consumption advisories. Some states have warned residents not to eat any fish caught in lakes or rivers with dangerous levels of contamination.
Because there is no federal guidance on safe PFAS concentration in fish, the “do not eat” threshold varies greatly among states. For example, the cutoff is 25.7 parts per billion in New Hampshire and 800 ppb in Alabama.
In 2022, the FDA issued a recall for canned clams from China that had high concentrations of PFOA. FDA cautioned that the consumption of more than 10 ounces of these clams per month could be harmful.
PFAS are called “forever chemicals” because they do not break down in the environment and can accumulate in soil, water, fish, animals and humans. The CDC has found that most people living in the United States have detectable levels of PFAS in their blood. Certain groups are at risk of high PFAS exposure including those working at airports, military bases, wastewater treatment plants, landfills, and farms where biosolids have been spread. The most well-studied PFAS are excreted slowly, with half-lives in the human body ranging from 3 to 8 years.
In 2022, the National Academies of Sciences, Engineering and Medicine published a sweeping federally funded report that associated PFAS exposure with serious health issues such as cancer, low birth weight, developmental defects, reduced immune response, thyroid dysfunction, and liver toxicity. More recent evidence has linked PFAS exposure to increased risk of pregnancy-induced hypertension, testicular cancer, breast cancer, thyroid disease, liver enzyme elevations, and ulcerative colitis. The International Agency for Research on Cancer has classified perfluoroctanoic acid as carcinogenic and perfluorooctanesulfonic acid as possibly carcinogenic to humans.
The US Geological Survey estimates that PFAS have contaminated at least 45 percent of the nation’s drinking water. Municipalities need to invest millions of dollars in new infrastructure to reduce the levels of PFAS in drinking water. There are two major technologies that most utilities consider for removing PFAS from drinking water: activated carbon or ion exchange systems. PFAS bind tightly to activated carbon. Ion exchange systems work by flowing water over charged particles that can remove PFAS. Ion exchange systems are typically even better at lowering PFAS concentrations than activated carbon systems, but they are more expensive.
Major PFAS producers (Chemours, DuPont, and Corteva) have reached a $1.19 billion settlement with water providers. The money will be used to upgrade treatment plants so they can filter PFAS from drinking water. 3M has also reached a $10 billion settlement with water providers and agreed to stop manufacturing and using the chemicals by the end of 2025.
On April 10, 2024, the Biden administration introduced the first national standards to eliminate the most prevalent PFAS from American drinking water sources. The new regulation sets legally enforceable limits for only six of the chemicals: PFOA, PFOS, PFNA, PFHxS, PFBS and HFPO-DA (GenX). But because PFAS typically occur in mixtures of related chemicals, the regulation is likely to reduce exposure to more than just those directly specified. Also, many of the treatment technologies that will be implemented to eliminate the specified PFAS will also reduce unspecified PFAS that might be present. Utilities have a 5-year deadline to comply.
However, the future of such measures is unclear. President Trump has appointed former chemical industry executives to the EPA and has withdrawn in-progress regulations, including the proposal to limit PFAS in wastewater.
The European Union is considering a blanket ban of approximately 10,000 PFAS.
References
KFF Health News, Dec 1, 2023
Locally caught freshwater fish across the United States are likely a significant source of exposure to PFOS and other perfluorinated compounds, Evironmental Research 2023, 220: https://doi.org/10.1016/j.envres.2022.115165
FDA Shares Results on PFAS Tesing in Seafood, July 15, 2022, https://www.fda.gov/food/cfsan-constituent-updates/fda-shares-results-pfas-testing-seafood?utm_campaign=wp_the_health_202&utm_medium=email&utm_source=newsletter&wpisrc=nl_health202
National Academies, Guidance on PFAS Testing and Health Outcomes, 2022; https://www.nationalacademies.org/our-work/guidance-on-pfas-testing-and-health-outcomes?utm_campaign=wp_the_health_202&utm_medium=email&utm_source=newsletter&wpisrc=nl_health202#sectionPublications
PFAS Information for Clinicians. Agency for for Toxic Substances and Disease Registry (ATSDR): https://www.atsdr.cdc.gov/pfas/health-effects/us-population.html
Knutson J. Companies to pay billions in "forever chemical" water pollution settlements. Axios, June 2, 2023. https://www.axios.com/2023/06/02/pfas-chemicals-companies-billions-settlement-water
Criswell R, Fleisch AF, Ducatman A. Clinical Implications of New Drinking Water Regulation for “Forever Chemicals”. JAMA. 2024;332(10):785–786. doi:10.1001/jama.2024.12705.
Burakoff M. The Forever Fall Out. Audubon, Spring 2025.
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