The Known Health Effects of PFAS: What Science Tells Us So Far

Per- and polyfluoroalkyl substances (PFAS), commonly referred to as “forever chemicals”, have become an increasingly urgent public health concern. Used in thousands of consumer and industrial products, from nonstick cookware to firefighting foams, these synthetic chemicals are incredibly resistant to heat, water, and oil. Their chemical stability means they persist in the environment and accumulate in the human body over time. As public awareness grows, so does the body of scientific evidence linking PFAS exposure to a range of health effects.

One of the most serious health concerns linked to PFAS is cancer. While the science is still developing, the U.S. Environmental Protection Agency (EPA) has found evidence that certain PFAS, especially a type called PFOA, may increase the risk of cancer. This lines up with a large health study that looked at communities exposed to contaminated water, which found a possible connection between PFOA and higher rates of kidney and testicular cancer.

PFAS can also weaken the immune system. A study in children found that higher levels of PFAS in the body were tied to lower responses to common vaccines, meaning the body didn’t produce as many protective antibodies as it should have. EPA and ATSDR report that certain PFAS are linked to reduced vaccine response; longitudinal studies in children show lower antibody levels with higher PFAS exposure. This is a serious concern during things like flu season or public health emergencies.

Hormones and development are another focus. European risk assessors and public-health agencies note links between PFAS exposure and pregnancy complications (like low birth weight and high blood pressure), altered thyroid hormones, and potential delays in development—concerns that have helped drive tighter European policy. The European Environment Agency (EEA) continues to synthesize new evidence, including PFAS polymer uses and their broader environmental footprint.

Cholesterol levels and liver function are also affected by PFAS exposure. Analyses of large-scale health datasets, have found that people with higher levels of PFAS in their blood tend to have increased total and LDL (“bad”) cholesterol levels. PFAS exposure has also been associated with elevated liver enzymes, indicating potential liver inflammation or damage.

Regulatory action in Europe is accelerating. Five European authorities—Denmark, Germany, the Netherlands, Norway, and Sweden—submitted a REACH “universal” PFAS restriction proposal to the European Chemicals Agency (ECHA) in 2023. ECHA received 5,600+stakeholder comments during its consultation, signaling broad engagement as the EU weighs sweeping limits across thousands of PFAS uses.

Finally, Europe is mapping the scale of contamination. The EEA’s 2024 briefing compiled reported monitoring data and compared PFOS levels against regulatory thresholds to give an initial picture of PFAS pressures across European waters—evidence that supports targeted cleanup and prevention.

Human exposure to PFAS occurs primarily through contaminated drinking water, food (especially from packaging like grease-resistant wrappers), indoor dust from treated carpets and furniture, personal care products, and occupational exposure—particularly for firefighters and chemical plant workers. Once PFAS enter the body, they do not break down easily. Instead, they accumulate in the blood, liver, and kidneys, sometimes persisting for years.

While there is still more to learn about the full extent of PFAS’s health effects, the evidence to date makes one thing clear: PFAS pose real risks to human health, especially with long-term or high-level exposure. As research continues and regulations evolve, it’s essential to stay informed, push for stronger protection, and make safer choices where possible.

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Sources

1.     ATSDR. How PFAS Impacts Your Health. 2025. https://www.atsdr.cdc.gov/pfas/about/health-effects.html

2.     U.S. EPA. Our Current Understanding of the HumanHealth and Environmental Risks of PFAS. 2024. https://www.epa.gov/pfas/our-current-understanding-human-health-and-environmental-risks-pfas

3.     U.S. EPA. Human Health Toxicity Assessment for Perfluorooctanoic Acid (PFOA) – Fact Sheet. Final assessment (Apr 2024); factsheet (Jan 2025). https://www.epa.gov/system/files/documents/2025-01/pfoa-human-health-toxicity-assessment-infographic-factsheet.pdf

4.     IARC/WHO. IARC Monographs Volume 135: PFOA (Group 1) and PFOS (Group 2B). 2025. https://www.iarc.who.int/news-events/iarc-monographs-volume-135-perfluorooctanoic-acid-pfoa-and-perfluorooctanesulfonic-acid-pfos/

5.     National Academies (NASEM). Guidance on PFAS Exposure, Testing, and Clinical Follow-Up. 2022. https://nap.nationalacademies.org/catalog/26156

6.     EFSA Panel on Contaminants. Risk to human health related to the presence of PFAS in food (sets TWI 4.4 ng/kg bw/week for sum of 4 PFAS). EFSA Journal2020;18(9):e06223. https://www.efsa.europa.eu/en/efsajournal/pub/6223

7.     C8 Science Panel. Probable Link Reports (Mid-Ohio Valley). 2012. http://www.c8sciencepanel.org/prob_link.html

8.     ECHA. PFAS Universal Restriction (REACH) –Registry entry. 2023–ongoing. https://echa.europa.eu/registry-of-restriction-intentions/-/dislist/details/0b0236e18663449b

9.     ECHA. News: ECHA receives more than 5,600 comments on PFAS restriction proposal. Sept 26, 2023. https://echa.europa.eu/-/echa-receives-5-600-comments-on-pfas-restriction-proposal

10.    European Environment Agency (EEA). PFAS pollution in European waters (PFOS exceedances vs EQS). 2024. https://www.eea.europa.eu/en/analysis/publications/pfas-pollution-in-european-waters

11.     Grand jean P, et al. Serum vaccine antibody concentrations in children exposed to perfluorinated compounds. JAMA. 2012;307(4):391–397. https://pubmed.ncbi.nlm.nih.gov/22274686/

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