Published April 2026 — Updated Regularly

PFAS Health Effects: A Comprehensive Guide to Forever Chemical-Linked Conditions

Last updated: May 2026

Per- and polyfluoroalkyl substances (PFAS) are a group of over 12,000 synthetic chemicals that have been linked to serious health conditions — from kidney cancer to thyroid disease to problems during pregnancy. Understanding what PFAS exposure does to the body matters if you've been drinking contaminated water, live near a military base or industrial site, or have a diagnosis you can't fully explain.

Here's what the current science actually shows.

How PFAS Get Into the Body

PFAS enter the human body through multiple routes:

• Drinking water: The most significant source for most Americans. PFAS dissolve in water and are not removed by standard water treatment.
• Food: PFAS can be present in food grown on contaminated soil, in packaging materials (grease-resistant food wrappers, popcorn bags), and in fish from contaminated waterways
• Air: Communities near industrial PFAS sources may inhale airborne particles
• Consumer products: Nonstick cookware, stain-resistant fabrics, waterproof clothing, and dental floss (some brands) can be PFAS sources
• Occupational exposure: Firefighters using AFFF foam and factory workers at PFAS manufacturing facilities have some of the highest PFAS blood levels ever measured

Once in the body, PFAS accumulate in the blood, liver, kidneys, and bones. Because they do not break down, they build up over years and decades — a process called bioaccumulation. This is what makes chronic low-level exposure so dangerous.

PFAS Health Effects: What the Science Shows

Kidney Cancer

Kidney cancer is one of the health conditions most strongly linked to PFAS exposure in the scientific literature. Multiple studies have found elevated kidney cancer rates in communities with PFAS-contaminated water, among firefighters with occupational PFAS exposure, and in workers at PFAS manufacturing facilities.

A 2020 study in Environmental Health Perspectives found a significant association between PFAS blood levels and kidney cancer risk. The National Academy of Sciences' 2022 analysis of PFAS health evidence concluded there is "sufficient" evidence to establish a causal link between PFAS exposure and kidney cancer.

Testicular Cancer

Testicular cancer has been significantly associated with PFAS exposure in multiple independent studies. Men who were exposed to PFAS through drinking water or occupational settings show elevated rates of this cancer. A study of Danish workers found a strong association between PFAS exposure and testicular cancer risk.

The National Academy of Sciences' 2022 review also concluded there is "sufficient" evidence linking PFAS exposure to testicular cancer.

Thyroid Disease

PFAS disrupts the thyroid gland's ability to produce hormones by interfering with thyroid-hormone binding proteins. Research consistently finds that people with higher PFAS blood levels are more likely to have thyroid disease — including hypothyroidism (underactive thyroid), hyperthyroidism (overactive thyroid), and thyroid cancer.

The thyroid-PFAS link is particularly concerning for pregnant women and children. Thyroid hormones are essential for normal brain development in fetuses and infants. Disruption of thyroid function during pregnancy is associated with developmental problems in children.

High Cholesterol (Dyslipidemia)

One of the most consistent PFAS health effects found across dozens of studies is elevated cholesterol. People with higher PFAS blood levels consistently show higher total cholesterol and LDL ("bad") cholesterol levels. The mechanism is not fully understood, but PFAS appears to interfere with cholesterol metabolism in the liver.

High cholesterol itself is not a disease but is a major risk factor for heart disease and stroke — so PFAS-related cholesterol increases have implications beyond the cholesterol finding alone.

Immune System Effects

PFAS has a documented effect on the immune system — specifically, it reduces the body's ability to mount an immune response. Studies have found that children with higher PFAS exposure produce fewer antibodies in response to vaccines. Adults with higher PFAS levels show reduced immune function as well.

The immune suppression effect of PFAS means that exposed individuals may get sicker from infections, may respond less well to vaccines, and may have a harder time fighting off diseases — including cancer.

Pregnancy Complications

PFAS exposure during pregnancy is associated with multiple serious complications:

• Preeclampsia: A dangerous pregnancy complication involving high blood pressure. Women with higher PFAS exposure show elevated rates of preeclampsia.
• Gestational hypertension: High blood pressure during pregnancy even without preeclampsia
• Reduced birth weight: Babies born to mothers with higher PFAS levels tend to weigh less at birth
• Preterm birth: Some studies find associations with earlier delivery

Developmental Effects in Children

Children are particularly vulnerable to PFAS because they drink more water relative to body weight and because developing bodies are more sensitive to chemical disruption. PFAS exposure in children has been linked to:

• Reduced immune response to vaccines
• Higher rates of obesity
• Delayed puberty
• Reduced birth weight and growth effects
• Possible learning and behavioral effects (research ongoing)

Liver Disease

PFAS are processed by the liver, and high exposure levels have been associated with elevated liver enzymes and, in some studies, non-alcoholic fatty liver disease (NAFLD). The liver damage mechanism is an area of active research.

Ulcerative Colitis

PFAS exposure has been linked to inflammatory bowel disease, specifically ulcerative colitis, in multiple studies. The link between PFAS and immune system disruption may explain this connection, as ulcerative colitis is an immune-mediated condition.

Bladder Cancer and Other Cancers

While kidney and testicular cancers have the strongest evidence, PFAS has also been associated with elevated rates of bladder cancer, breast cancer, and prostate cancer in some studies. The National Academy of Sciences categorized these as having "limited or suggestive" evidence — meaning the associations are seen in the data but not as definitively established as kidney and testicular cancer.

How Much PFAS Exposure Is Dangerous?

There is no known safe level of PFAS. The EPA's new drinking water limits — set at 4 parts per trillion for PFOA and PFOS — reflect the agency's assessment that even very small amounts of exposure over time can cause harm, particularly for vulnerable populations like pregnant women, infants, and children.

The risk increases with both the concentration of PFAS (how much per unit of water or blood) and the duration of exposure (how many years). People who drank contaminated water for decades face much higher risk than someone who moved into a contaminated area recently.

Getting Tested for PFAS

There is a blood test that can measure your PFAS levels. It is called serum PFAS testing and is available through some doctors and through environmental health labs. Your doctor can order this test if you are concerned about exposure.

The results tell you your current blood PFAS levels, but interpreting them is complex — the test does not tell you definitively whether you will develop a particular disease, and there is no treatment to remove PFAS from the body. The main value is establishing your exposure level for medical and legal purposes.

When to See a Doctor

You should discuss PFAS exposure with your doctor if:

• You live or lived near a military base, industrial PFAS source, or known contaminated water supply
• You are a firefighter or work in an industry with potential PFAS exposure
• You have been diagnosed with any of the conditions listed above and are uncertain of the cause
• You are pregnant or planning to become pregnant and may have had PFAS exposure

Your Legal Rights

If you were exposed to PFAS through contaminated drinking water and have developed kidney cancer, testicular cancer, thyroid disease, or another PFAS-linked condition, you may have legal claims. Companies like 3M, DuPont, Chemours, and Tyco Fire Products manufactured and distributed PFAS-containing products for decades while concealing what they knew about the health risks.

Personal injury claims in AFFF MDL 2873 are still actively accepting cases. Military veterans and civilians who developed cancer from PFAS exposure near military installations may qualify for significant compensation.

Find out if you qualify for a PFAS lawsuit →

Sources

• National Academies of Sciences, Engineering, and Medicine. "Guidance on PFAS Exposure, Testing, and Clinical Follow-Up." 2022.
• U.S. EPA. "EPA Sets Maximum Contaminant Levels for Six PFAS Compounds." April 2024.
• ATSDR. "Toxicological Profile for Perfluoroalkyls." 2021.
• Fenton SE, et al. "Per- and Polyfluoroalkyl Substance Toxicity and Human Health Review." Toxicological Sciences, 2021.