‘Forever Chemicals’ Study: PFAS in Tap Water Linked to Increased Risk of Cancer

Per- and polyfluoroalkyl substances (PFAS), commonly known as “forever chemicals,” have become a pervasive environmental and public health concern. Their unique chemical properties, which make them resistant to heat, water and oil, have led to their widespread use in various industrial and consumer products.

However, this same persistence means they do not break down easily, accumulating in the environment and our bodies over time, posing significant health risks. Due to their persistent nature, PFAS have become widespread environmental contaminants, particularly in drinking water sources.

Now, new research published in 2025 has found an alarming link between PFAS in tap water and an increase in the incidence of several different types of cancer.

Study: PFAS in drinking water linked to cancer

A study published in the Journal of Exposure Science & Environmental Epidemiology in January 2025 examined the relationship between PFAS levels in U.S. drinking water and county-level cancer incidence from 2016 to 2021. Researchers utilized data from the Surveillance, Epidemiology, and End Results (SEER) Program for cancer incidence and the Unregulated Contaminant Monitoring Rule (UCMR) for PFAS concentrations in public water systems.

Specifically, they analyzed data from UCMR3 (2013-2015) and UCMR5 (2023-2024), which measured various PFAS compounds, including PFOA, PFOS, PFNA, PFHxS, PFHpA, PFBS, PFBA, PFHxA, PFPeA and PFPeS.​

The study found significant associations between PFAS contamination in drinking water and increased incidence of cancers in the digestive, endocrine, oral cavity/pharynx and respiratory systems, with incidence rate ratios (IRRs) ranging from 1.02 to 1.33. Notably, perfluorobutanesulfonic acid (PFBS) showed the strongest association with oral cavity and pharynx cancers (IRR: 1.33).

Sex-specific analyses revealed that in males, PFAS exposure was linked to cancers of the urinary system, brain, leukemia and soft tissues, while in females, associations were observed with thyroid, oral cavity/pharynx and soft tissue cancers. The researchers estimated that PFAS in drinking water could contribute to approximately 4,626 to 6,864 incident cancer cases annually in the U.S., depending on the data set used.​

Other dangers of forever chemicals

Beyond cancer, PFAS exposure has been linked to other health issues, including liver damage, immune system disruption, thyroid disease, developmental delays in children and decreased fertility. Their persistence in the environment and bioaccumulative nature make them particularly concerning, as they can remain in the human body for extended periods.​

Studies focused on the effects of PFAS have examined how these chemicals impact human health through methods like:

• Epidemiological studies: These studies analyze the relationship between PFAS exposure and health outcomes in large populations.
• Toxicological studies: These studies examine the effects of PFAS on cells and animals to understand the mechanisms of toxicity.
• Exposure assessments: These studies measure PFAS levels in environmental samples (water, soil, air) and human samples (blood, urine).

Findings from these type research studies consistently indicate that PFAS exposure is associated with a range of adverse health effects, including:

• Increased cholesterol levels
• Immune system dysfunction
• Liver damage
• Increased risk of certain cancers (such as kidney and testicular)
• Developmental effects in infants and children
• Reproductive issues

These studies reinforce that even low levels of PFAS exposure can have detrimental effects on human health.

Beyond that, the broader dangers of forever chemicals include:

• Environmental persistence: PFAS contaminate soil, water and air, leading to long-term exposure for humans and wildlife.
• Bioaccumulation: PFAS accumulate in the food chain, posing risks to animals and humans who consume contaminated food.
• Widespread exposure: Due to their use in numerous products, PFAS are found in the blood of most people worldwide.
• Disruption of endocrine systems and hormonal balances.

How to limit exposure

While eliminating PFAS exposure entirely is challenging, individuals can take steps to reduce their risks. To mitigate exposure to forever chemicals, individuals can take several steps:​

1. Test drinking water: If you rely on well water or have concerns about your municipal water, test for PFAS.
2. Water filtration: Utilize home water filtration systems certified to reduce PFAS levels.​
3. Product awareness: Avoid products known to contain PFAS, such as certain non-stick cookware, stain-resistant fabrics and water-repellent clothing.​
4. Choose PFAS-free products: Look for products labeled “PFAS-free” or “PFOA/PFOS-free.”
5. Reduce processed food intake: Some food packaging contains PFAS.
6. Stay informed: Keep abreast of local water quality reports and any advisories related to PFAS contamination.​
7. Advocate for regulation: Support policies and regulations aimed at monitoring and reducing PFAS emissions and usage.​

Conclusion

• This major study underscores the critical need for ongoing monitoring of PFAS in drinking water and further research into their health impacts.
• Given the associations between PFAS exposure and increased cancer incidence, it is imperative to implement strategies to reduce exposure and safeguard public health.​
• The growing body of scientific evidence really emphasizes the significant health risks associated with PFAS exposure.
• The persistence and widespread presence of these “forever chemicals” demand urgent action to mitigate their impact.
• By understanding the dangers and taking proactive steps to limit exposure, individuals and communities can work toward protecting public health and the environment.
• Continued research and regulatory efforts are crucial to address this ongoing challenge.