PFAS and cancer: which types are linked to forever chemicals?

One of the most serious concerns about PFAS is their connection to cancer. These “forever chemicals” do not break down in the environment or in our bodies, and decades of accumulating research now point to real cancer risks for people with elevated exposure. If you have been reading about PFAS on this site, you already know they show up in drinking water, cookware, food packaging, and dozens of other everyday products. The cancer question is why that matters so much.

This is not a theoretical worry. Major health agencies have weighed in, and large population studies are filling in the picture. Here is what we know, which cancers have the strongest links, and what you can do to lower your family’s exposure.

The research connecting PFAS to cancer

In late 2023, the International Agency for Research on Cancer (IARC), which is part of the World Health Organization, reclassified PFOA as a Group 1 carcinogen. That is the highest classification, meaning there is sufficient evidence that it causes cancer in humans. PFOS, another common PFAS compound, was classified as “possibly carcinogenic” (Group 2B).

A 2024 study from USC’s Keck School of Medicine analyzed PFAS contamination in public water systems across the United States and found that counties with higher PFAS levels in their drinking water had 2% to 33% higher cancer incidence rates depending on the cancer type. The researchers estimated that PFAS-contaminated water may contribute to roughly 6,800 additional cancer cases per year in the U.S. alone.

That is a staggering number, and it underscores why filtering your water and reducing product-based exposure is worth the effort.

Which cancers are linked to PFAS?

Not all cancers have equal evidence linking them to PFAS. Here is what the research supports most strongly.

Kidney cancer

Kidney cancer has one of the most consistent associations with PFAS exposure. Multiple epidemiological studies, including research on communities near PFAS manufacturing plants and military bases, have found elevated kidney cancer rates among people with high PFAS blood levels. The C8 Health Project, which studied tens of thousands of people exposed to PFOA-contaminated water near a DuPont plant in West Virginia, identified a “probable link” between PFOA and kidney cancer.

Testicular cancer

Testicular cancer is the other cancer type with strong epidemiological support. The same C8 Health Project found elevated rates among exposed populations. PFAS are known endocrine disruptors (we cover this in detail in our PFAS and endocrine disruption guide), and the hormonal interference may play a role in testicular cancer development.

Liver cancer

The liver is where PFAS accumulate most heavily in the body, so it is not surprising that liver cancer shows up in the research. Animal studies have consistently demonstrated liver tumors in rodents exposed to PFOA and PFOS, and human studies have found associations between PFAS exposure and liver damage markers that precede cancer.

Thyroid cancer

Given that PFAS disrupt thyroid hormones, the link to thyroid cancer has been an active area of research. The Vanderbilt University study from 2026 found that PFAS disrupted signaling pathways involved in cancer development within thyroid tissue. Population-level studies have shown mixed but increasingly supportive results.

Other cancer types under investigation

The USC/Keck study found elevated incidence rates for digestive cancers, endocrine cancers, respiratory cancers, and oral cancers in high-PFAS areas. The patterns were sex-specific: some cancer types showed stronger associations in men, others in women. Research is ongoing, and the list of potentially linked cancers may grow as more data comes in.

How PFAS may cause cancer

PFAS do not appear to cause cancer through a single mechanism. Researchers have identified several pathways that likely work together:

First, PFAS cause chronic inflammation. Persistent low-grade inflammation is a well-established driver of cancer development, and PFAS trigger inflammatory responses in multiple organ systems.

Second, PFAS disrupt hormones. As endocrine disruptors, they interfere with the signaling that normally keeps cell growth in check. Hormonal imbalance is a known risk factor for hormone-sensitive cancers.

Third, PFAS may interfere with the immune system’s ability to detect and destroy abnormal cells. Studies have shown that PFAS suppress certain immune functions, which could allow precancerous cells to proliferate unchecked.

Fourth, PFAS accumulate. Unlike many environmental toxins, PFAS have half-lives measured in years inside the human body. This means exposure compounds over time, and the total body burden keeps rising unless new exposure is actively reduced.

What you can do to reduce your risk

You cannot control every source of PFAS exposure, but you can eliminate the biggest ones. Here is where to focus.

Filter your drinking water

Contaminated drinking water is the primary exposure route for millions of Americans. A high-quality water filter that removes PFAS is the single most impactful change you can make. The Clearly Filtered Water Pitcher is independently tested to remove over 99% of PFAS, including PFOA and PFOS. It is affordable, requires no installation, and the filters last about four months.

If you want to know what is actually in your water before choosing a filter, start with a lab test. Our PFAS water testing guide walks through the options.

Swap out nonstick cookware

Traditional nonstick coatings are made from PFAS compounds. When heated, especially above medium heat, they can release trace amounts into food and kitchen air. Cast iron, stainless steel, and ceramic-coated pans are all PFAS-free alternatives. Our cookware guide compares the options.

Reduce food packaging exposure

Grease-resistant food packaging, including fast food wrappers, microwave popcorn bags, and some takeout containers, often contains PFAS. Where you can control it, store food in glass or stainless steel. Our food storage guide covers the kitchen in detail.

Check personal care products and textiles

PFAS are used in waterproof cosmetics, stain-resistant clothing, and some dental floss. The PFAS Free Life Database has verified products across hundreds of categories, so you can search for clean alternatives by product type.

Frequently asked questions

Which cancers are most strongly linked to PFAS?

Kidney cancer and testicular cancer have the strongest epidemiological evidence linking them to PFAS exposure, based on decades of research including the C8 Health Project. Liver cancer, thyroid cancer, and several digestive and endocrine cancers also show associations in population-level studies. The International Agency for Research on Cancer classified PFOA as a Group 1 carcinogen (sufficient evidence of causing cancer in humans) in 2023.

Does PFAS in drinking water cause cancer?

PFAS-contaminated drinking water has been associated with increased cancer incidence in multiple studies. A USC/Keck School of Medicine study found that counties with higher PFAS in their public water systems had 2% to 33% higher cancer rates across several cancer types, with an estimated 6,800 additional cancer cases per year in the U.S. attributable to PFAS water contamination. Filtering your water with a system that removes PFAS is one of the most effective steps you can take.

How long does it take for PFAS to leave the body?

Most PFAS compounds have biological half-lives of 2 to 8 years, meaning it takes that long for your body to eliminate half of the accumulated amount. PFOA has a half-life of about 3.5 years, while PFOS can persist for 5 years or more. This is why reducing ongoing exposure is so important: even after you stop taking in new PFAS, your existing body burden declines slowly.

Can I get tested for PFAS exposure?

Yes. Blood tests can measure PFAS levels, and some labs offer panels that test for multiple PFAS compounds. Your doctor can order these tests, and some environmental health clinics specialize in PFAS exposure assessment. If you live near a known contamination site or military base, testing may be especially worthwhile.

*Research references: IARC PFOA Classification 2023

USC/Keck PFAS Cancer Study

C8 Health Project*