What Are the PFAS Health Effects?
- Last updated: July 17, 2025
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Contributor:
nicky
Per- and polyfluoroalkyl substances, commonly called PFAS, have been manufactured since the 1950s for products that resist heat, stains, and water. PFAS health effects have become a major focal point for public health agencies, as evidence suggests these chemicals can remain in the human body and environment longer than many other pollutants.
According to the Centers for Disease Control and Prevention, PFAS have been detected in the blood of nearly all tested Americans, at about 97 percent. They have also been found in wildlife globally, including polar bears in the Arctic. The Environmental Protection Agency (EPA) has responded with regulations and guidance that aim to reduce PFAS exposure in drinking water and consumer products, but research continues to reveal new types of PFAS, along with uncertainties over their human health impacts.
We recognize that many people worry about confirmed and potential risks, especially if they live in areas with known water contamination or work in industries that handle PFAS. In this article, we present current data on how PFAS enter the body, why they persist for so long, and what documented health outcomes have been linked to these substances. We also address frequently asked questions about testing, possible health claims, and broader regulatory efforts surrounding these chemicals.
How PFAS enters the body
PFAS contaminants typically enter human systems through ingestion or inhalation. Most exposure results from drinking water that has been in contact with PFAS, such as areas near industrial facilities or sites that used firefighting foam. Research indicates that fish, meat, and dairy products can also be sources when animals accumulate PFAS from contaminated feed or water. According to the EPA, PFAS can be found in various consumer products, including some food packaging.
In areas with confirmed contamination, local water supplies might contain elevated PFAS concentrations. We have seen this documented in several states and communities, prompting measures such as water treatment upgrades or the use of at-home filtration systems. Our own review suggests that many individuals concerned about PFAS exposure rely on solutions like carbon filters or reverse osmosis to reduce contamination. To learn more about these approaches, some refer to pfas in drinking water and how to remove pfas from water.
Occupational exposure presents another pathway, especially in factories that produce or recycle PFAS. Workers can inhale PFAS-containing dust or fumes, increasing their body burden over time. Personal protective equipment and exposure monitoring are therefore central to workplace safety guidelines. Even beyond direct industrial contact, PFAS can be released to the air and travel long distances before eventually settling into soil or water.
Why PFAS stay in the body so long
Several PFAS compounds have chemical structures that make them resistant to breakdown. They are highly stable, which helps them function well in products that repel water or stains. Unfortunately, that same resilience means they do not degrade easily in the body or the environment.
Studies published by the National Health and Nutrition Examination Survey (NHANES) suggest that blood levels of older PFAS chemicals, like PFOA and PFOS, have decreased in the general population since industry phased them out in the early 2000s. However, new PFAS continue to be invented and used, which makes it challenging to track and understand all potential variants. Additionally, changes in PFAS manufacturing do not automatically eliminate legacy contamination.
When PFAS accumulate in tissue, the human body can take years to eliminate them. The exact half-life depends on the specific compound, but many remain detectable for extended periods. Some PFAS tend to bind to proteins in the blood and liver, which contributes to their lengthy retention time. More research is ongoing to determine why individuals vary in how quickly they can clear PFAS, and whether genetics, diet, or health status play roles in these differences.
Confirmed health risks from PFAS exposure
Numerous studies have examined possible links between PFAS and adverse health outcomes. Although scientific consensus evolves as new data emerge, certain potential risks have been documented by organizations such as the National Toxicology Program (NTP) and the EPA. The NTP concluded that two well-studied PFAS compounds, PFOA and PFOS, can suppress the antibody response and pose a hazard to immune function.
Other reports indicate that PFAS exposure is associated with issues like liver damage, higher cholesterol, and reproductive harm. Researchers typically focus on long-chain PFAS, considered more likely to bioaccumulate in people and animals. In the United States, the EPA has established drinking water regulations for some of these substances, citing concerns about long-term exposure.
Despite ongoing research, uncertainties remain about which PFAS are most harmful at specific concentrations. We note that certain studies highlight immune system suppression and potential carcinogenic effects, but large-scale, longitudinal research is still underway to pinpoint exactly how different PFAS may trigger health effects under various exposure scenarios.
PFAS and cancer risk
Multiple epidemiological studies have reported associations between PFAS exposure and certain cancers, including kidney, testicular, and possibly breast cancer. The C8 Science Panel, formed to study communities near a West Virginia plant, concluded there was a probable link between PFOA and testicular and kidney cancers. Additional studies have found connections between long-chain PFAS and several tumor types, but these do not necessarily prove that PFAS directly cause cancer in every individual.
Laboratory models and animal testing have helped researchers identify potential mechanisms, such as disruption of cell signaling and hormone regulation. Ongoing studies aim to clarify whether critical windows of exposure exist, such as during childhood or pregnancy. We can refer to pfas and cancer for more details on how PFAS might elevate cancer risks. While researchers remain cautious in interpreting results, many regulatory actions, including the EPA’s proposal to list certain PFAS as hazardous substances, reflect concerns about cancer and other severe outcomes.
PFAS and thyroid disease
Thyroid health depends on finely regulated hormone levels, and various PFAS have been implicated in disrupting that balance. The C8 Science Panel concluded there is a probable link between PFOA exposure and thyroid disease, particularly hypothyroid conditions. According to this research, PFAS may interfere with the binding and transport of thyroid hormones, although more evidence is needed to pinpoint the thresholds at which these chemicals become harmful.
Thyroid dysfunction can manifest in fatigue, weight gain, or mood changes, among other symptoms. Some communities near industrial sites have reported higher rates of thyroid problems, prompting further investigation. However, factors like genetics, diet, and iodine intake may also affect thyroid health. We recommend that anyone suspecting exposure and experiencing thyroid-related symptoms consult a healthcare professional to discuss potential testing and appropriate interventions.
PFAS and liver damage
Data from population studies show activity of specific liver enzymes increasing in individuals with higher PFAS levels. Persistent elevations in enzymes such as alanine aminotransferase (ALT) may indicate stress or damage to liver tissue. In extreme cases, chronic liver injury can progress to fibrosis or other severe conditions.
Animal studies support these findings. Scientists have observed changes in liver weight, cell structure, and function in test subjects exposed to certain PFAS concentrations. While not all PFAS produce identical effects, the general trend of liver impact aligns with larger epidemiological research. Authorities like the EPA continue to focus on identifying safe exposure levels in drinking water, as populations with prolonged exposure to high PFAS concentrations could be at a greater risk for liver-related diseases. It is important to note that factors such as alcohol use, viral infections, and other toxic exposures also contribute to liver damage, making it essential to interpret PFAS effects in a broader health context.
PFAS and immune system effects
A robust immune system typically responds to infections and vaccines by producing specific antibodies. However, the National Toxicology Program found that PFAS, particularly PFOA and PFOS, suppressed the antibody response in both humans and animals. Elevated exposure could potentially reduce vaccine effectiveness and increase susceptibility to certain infections.
Epidemiological findings have documented associations between long-chain PFAS exposure and autoimmune conditions, such as inflammatory bowel disease. Additional research indicates that immune cells might be less capable of launching normal defense responses after repeated PFAS contact. Children’s developing immune systems could be even more vulnerable, although scientific consensus has not fully identified the range of immunological impacts across different age groups.
PFAS and reproductive harm
PFAS exposure has been linked with various effects on reproductive health, including difficulties conceiving and potential disruptions to menstrual cycles. Certain studies suggest that PFAS might impair hormone function or disrupt signaling pathways important for healthy reproductive organs. Biologically, these chemicals can accumulate in blood and tissues over time, raising concerns about how chronic exposure might affect fertility.
For some individuals seeking medical explanations for infertility or recurrent miscarriages, PFAS has emerged as one among many possible environmental factors. Nonetheless, infertility can be multifactorial, influenced by genetics, lifestyle, and other health conditions. Ongoing research supported by the National Institute of Environmental Health Sciences (NIEHS) aims to clarify the magnitude and mechanisms of potential reproductive risks. Our observation is that some communities with notable PFAS exposures have also reported elevated rates of fertility challenges, though more in-depth, controlled studies are needed to confirm these patterns.
PFAS and pregnancy complications
Pregnant individuals can pass PFAS to their unborn children, as these chemicals can cross the placenta. Studies also show that PFAS can be transferred through breast milk, potentially contributing to neonatal exposure. While breastfeeding remains highly beneficial overall, scientists are examining whether sustained PFAS exposure in mothers might affect fetal development or increase the risk of complications such as preeclampsia.
Several investigations, including the C8 Science Panel and subsequent cohort analyses, have identified associations between PFAS concentrations in maternal blood and low birth weight or hypertensive disorders in pregnancy. Research continues to examine whether these outcomes directly result from PFAS exposure or other underlying factors, such as co-exposures to different pollutants or individual nutritional status. Those with chronic health issues who suspect high PFAS intake, especially via drinking water, often consult both obstetricians and environmental health specialists to better understand ways to mitigate potential risk. More details on pregnancy concerns can be found at pfas and preeclampsia.
PFAS and childhood development
Children may be more sensitive to PFAS impacts due to their developing organs and higher relative intake of food or water compared to adults. Many children drink formula made with tap water and consume other beverages that could be sources of PFAS. Ongoing experiments suggest that prenatal or early-life exposures can alter immune response and raise the likelihood of infections or allergies.
The potential for disrupted growth and developmental milestones has prompted research groups, funded by agencies like NIEHS, to follow children in communities with known PFAS contamination. Some parents also consider specialized products advertised as PFAS free, such as pfas free diapers, although the effectiveness of such measures can depend on the actual product formulations. Longitudinal monitoring through well-designed cohort studies will be critical to understanding whether mild delays or more significant developmental differences arise from PFAS exposure.
PFAS and high cholesterol
Surveys including cross-sectional and longitudinal data have demonstrated that PFAS exposure can correlate with elevated total and LDL (bad) cholesterol. One hypothesis is that PFAS disrupt lipid metabolism by affecting the proteins involved in cholesterol regulation. Adults and adolescents with higher PFAS levels have shown a greater likelihood of hypercholesterolemia.
The degree of elevation appears to vary, and experts caution that lifestyle factors, including diet and exercise, significantly influence cholesterol levels. However, a pattern of small but consistent increases has emerged across multiple studies. While additional research is needed to clarify the exact biochemical mechanisms, these findings have spurred more frequent cholesterol screenings for people with known high PFAS exposure.
PFAS and hormonal disruption
Beyond thyroid hormones, PFAS may also affect other endocrine pathways. Researchers are exploring whether these compounds interrupt estrogen, testosterone, or cortisol regulation. Hormonal imbalances can lead to a wide range of symptoms, including changes in body weight, mood, and metabolic function.
Laboratory tests in animals indicate that some PFAS can alter hormonal signaling at relatively low doses, although translating those results to human health risks is complex. Additional human epidemiological data is needed to confirm whether specific PFAS disrupt hormones in detectable ways at typical environmental exposures. Nevertheless, the possibility of endocrine disruption is an ongoing concern and has been part of the scientific rationale behind regulating PFAS in water supplies.
What health conditions qualify for legal or medical claims?
Individuals who develop chronic illnesses potentially linked to PFAS often ask about legal or medical recourse. In some cases, people living near industrial discharge sites or military bases with firefighting foam use have pursued lawsuits, alleging contamination led to cancers or other injuries. However, legal standards for proving causation can be rigorous. Each claim often hinges on identifying a clear exposure pathway, medical diagnosis, and recognized scientific evidence connecting that condition to PFAS.
While there is no single list of guaranteed qualifying conditions, common inquiries include cancer, thyroid disease, and immune-related disorders. Attorneys familiar with PFAS litigation can offer more detailed guidance on how to document exposure and demonstrate that harm likely resulted. We recommend consulting specialists to evaluate your case. For those seeking a free case review, resources are available at Legal Claim Assistant, where potential clients can connect with lawyers experienced in PFAS lawsuits. It is also advisable to speak with medical professionals knowledgeable about PFAS-related health assessments.
Can you get tested for PFAS exposure?
Yes, blood tests can detect certain PFAS compounds, particularly PFOA and PFOS. However, these tests typically do not provide a direct diagnosis of how PFAS has impacted health. They simply indicate the presence and concentration of these substances in the bloodstream. If you suspect contamination in your vicinity, you may consult a pfas testing lab or speak with public health officials about expanded testing programs.
The EPA and some state agencies offer guidance on water sampling for residences or private wells, which can help individuals determine if removal systems are necessary. Regular monitoring, sometimes referred to as pfas monitoring, may be an option in areas with suspected or known contamination. While knowing PFAS levels can clarify exposure, research has yet to identify a precise threshold at which illness becomes inevitable. If you have a chronic health condition associated with PFAS in the scientific literature, sharing testing data with your healthcare team can provide additional context for treatment and potential interventions.
Frequently asked questions (FAQ)
What is the difference between PFOA and PFOS?
PFOA and PFOS are two of the most studied PFAS compounds. Both were phased out of many consumer products in the early 2000s due to concerns about persistence and potential toxicity. However, many replacement PFAS with similar structures have emerged, and their health risks are still under investigation.
Which PFAS are regulated by the EPA?
In April 2024, the EPA finalized National Primary Drinking Water Regulations for six PFAS. These include individual maximum contaminant levels for PFOA, PFOS, PFHxS, PFNA, and HFPO-DA, along with a Hazard Index approach for mixtures of these substances. Some decisions are undergoing reconsideration, but the key aim is to reduce harmful PFAS exposure for millions of people.
Does the new EPA regulation address all PFAS risks?
The regulation targets specific PFAS in drinking water and does not cover all PFAS found in the environment. Research on thousands of PFAS compounds remains ongoing. Broader legislation and additional policies may evolve to include other PFAS, depending on emerging data and risk assessments.
Can filters remove PFAS from drinking water?
Certain filtration methods can lower PFAS concentrations. Carbon filters and reverse osmosis systems have demonstrated effectiveness, though results vary by setup and compound. More details are available at do carbon filters remove pfas and does reverse osmosis remove pfas.
Where can I find more information on PFAS contamination or testing?
Many state health departments provide local advisories. Nationally, the EPA and CDC offer guidance on testing methods and health implications. You may also consult nonprofit environmental organizations or independent labs for further resources.
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