In thousands of communities across the United States, drinking water is contaminated with chemicals known as perfluoroalkyl and polyfluoroalkyl substances (PFAS). PFAS are used in a wide range of products such as non-stick cookware, water and stain repellent fabrics, and fire-fighting foam because they have properties that repel oil and water, reduce friction, and resist temperature changes (learn more). Exposure to PFAS has been linked to an increased risk of several adverse health effects, including certain cancers, thyroid dysfunction, small reductions in birth weight, and high cholesterol.
A report from the National Academies recommends that Centers for Disease Control (CDC), Agency for Toxic Substances and Disease Registry (ATSDR) should revise its existing PFAS clinical guidance to say that clinicians should offer education and blood testing to patients who are likely to have a history of elevated exposure to PFAS, such as those exposed through their work or who live in areas with known PFAS contamination. The CDC, ATSDR, and public health departments should support clinicians by creating educational materials on PFAS exposure, potential health effects, the limitations of testing, and the harms and benefits of testing.
PFAS contamination is global. PFAS have been detected even in regions with little human activity such as the Arctic and Antarctic seas. PFAS can enter the environment at sites where they are made, used, disposed of, or spilled, such as:
PFAS are mobile. They can be transported through rainwater run-off that then enters lakes, ponds, and other surface water, or seeps through the soil and migrates into groundwater (underground sources of drinking water).
In the United States, an estimated 2,854 locations across the 50 states and two territories have some level of PFAS contamination.
In the late 1990s perfluorooctanoic acid (PFOA) water contamination was identified in Parkersburg, WV (learn more ), which led 3M, a primary PFAS manufacturer, to begin a voluntary phase-out of some PFAS. The contamination in Parkersburg led to a class action lawsuit which identified several health effects related to PFAS exposure and established a medical monitoring program. Shortly thereafter, the U.S. Environmental Protection Agency (EPA) began requiring all community water systems that serve over 10,000 people to test for certain PFAS, leading more communities to learn their water was contaminated. Learn more about PFAS milestones.
PFAS contamination can be hard to detect. The properties that make PFAS persistent and mobile in the environment also make them particularly challenging to analyze. Analytical methods sensitive enough to detect environmentally relevant concentrations became widely available in the early 2010s, but these methods still allow identification of only a small fraction of the thousands of PFAS that have been created and used since the 1950s. As existing analytical methods improve it is likely that additional PFAS and new release sites will be identified.
PFAS exposure is highly complex and can take varied paths:
PFAS levels in people's bodies persist unless exposure ceases, and even after exposure stops, some PFAS are persistent in the human body until they are eliminated by natural processes. The time it takes for the human body to eliminate half of a substance is called the biological half-life. Half-life estimates range from days for some PFAS (e.g., PFBA) to years for other PFAS (e.g., PFOA, PFOS). It is generally assumed it takes five half-lives to get rid of a chemical after exposure has ceased.
Organizations such as the International Agency for Research on Cancer (IARC), the Agency for Toxic Substances and Disease Registry (ATSDR), and the EPA have linked exposure to PFAS (particularly PFOA and PFOS) to multiple cancers, thyroid dysfunction, small changes in birthweight, and high cholesterol. Most health effects or conditions found to be associated with PFAS exposure are already common in the general population and all have multiple known risk factors. This report provides an objective and authoritative review of current evidence to determine the likely association between exposure to PFAS and elevated risk of several human health effects. The report looked at studies only of the seven PFAS being monitored in the CDC’s National Report on Human Exposure to Environmental Chemicals. The available evidence was synthesized into four categories of association as shown in the table below.
The report recommends that ATSDR update its clinical guidance to offer education and blood testing to patients who are likely to have a history of elevated exposure to PFAS. To advise patients who are concerned about or would like to reduce their exposure to PFAS, clinicians should:
Clinicians counseling parents of infants on PFAS exposure should discuss infant feeding and steps that can be taken to lower sources of exposure to PFAS. Guidance to breastfeed remains the best feeding advice for most infants given the many benefits of breastfeeding for both mothers and babies.
Recommendation 4-1: Clinicians advising patients on PFAS exposure reduction should begin with a conversation with their patients to first determine how they might be exposed to PFAS (sometimes called an environmental exposure assessment) and what exposures the patient is interested in reducing.
The exposure assessment should ask questions about current occupational exposures to PFAS (such as work with fluorochemicals or firefighting) and exposure to PFAS through the environment. Known environmental exposures to PFAS include living in a community with PFAS contaminated drinking water, living near industries that use fluorochemicals, service in the military, and consumption of fish and game from areas with known or potential contamination.
Recommendation 4-2: If the patient may be exposed occupationally, such as a by working with fluorochemicals, or as a firefighter, clinicians should consult with occupational health and safety professionals knowledgeable of the workplace practices to determine the most feasible ways to reduce exposure.
Recommendation 4-3: Individuals with elevated PFAS in their drinking water may filter their water to reduce their exposure. Drinking water filters are rated by NSF International, an independent organization that develops public health standards for products. Search the NSF database online for PFOA to find filters that reduce the PFAS in drinking water included in the Committee's charge. Individuals who cannot filter their water may use another source of water for drinking.
Recommendation 4-4: In areas with known PFAS contamination, clinicians should advise patients that PFAS can be present in fish wildlife, meat, and dairy and direct patients to any local consumption advisories.
Recommendation 4-5: Clinicians can direct patients interested in learning more about PFAS to authoritative sources of information on how exposure to PFAS occurs and what actions to take for mitigation. Authoritative sources include the Pediatric Environmental Health Specialty Units (PEHSU), the ATSDR, and the EPA.
Recommendation 4-6: When clinicians are counseling parents of infants on PFAS exposure, they should discuss infant feeding and steps that can be taken to lower sources of PFAS exposure. The benefits of breastfeeding are well known; the American Academy of Pediatrics, the American Academy of Family Physicians, and the American College of Obstetricians and Gynecologists support and recommend breastfeeding for infants, with rare exceptions. Clinicians should explain that PFAS can pass through breast milk from a mother to her baby. PFAS may also be present in other foods, such as the water used to reconstitute formula and infant food, and potentially in packaged formula and baby food. It is not yet clear what types and levels of exposure to PFAS are of concern for child health and development.
Recommendation 4-7: Federal environmental health agencies should conduct research that evaluates PFAS chemical transfer to and concentrations in breastmilk and formula to generate data that can help parents and clinicians make shared informed decisions about breastfeeding.
Report advises ATSDR to update its guidance to say, clinicians should offer PFAS blood testing to patients who are likely to have a history of elevated exposure to PFAS. PFAS testing has many potential benefits, such empowering people to manage their own health, but it also carries some potential harms, such as stress about the health effects of PFAS exposure, or reduced property values if testing leads to knowledge of contamination. Patients should share in any decision making about PFAS testing with their clinician, and patients who do not want to be tested for PFAS should refuse testing.
Clinicians should explain to patients:
Recommendation 5-1: As communities with PFAS exposure are identified, governmental entities (CDC/ATSDR, public health departments, etc.) should support clinicians with educational materials about PFAS testing to discuss testing with their patients.
Educational materials should discuss:
Recommendation 5-2: Clinicians should offer PFAS testing to patients likely to have a history of elevated exposure. In all discussions of PFAS testing, clinicians should describe the potential benefits and harms of PFAS testing and the potential clinical consequences (such as additional follow-up), related social implications, and limitations of PFAS testing so the patient and clinician can make a shared, informed decision. Patients who are likely to have a history of elevated exposure to PFAS include those who have:
Most health effects or conditions found to be associated with PFAS exposure are already common in the general population and all have multiple known risk factors. Blood serum levels can help inform follow-up care and treatments for PFAS-associated health endpoints.
This flow chart provides an overview of how the Committee’s recommendations to ATSDR could be used for PFAS education, exposure assessment, and clinical follow-up.
Recommendation 5-3: Clinicians should use serum or plasma concentrations of the sum of PFAS* to inform clinical care of exposed patients, using the following guidelines for interpretation:
* Simple additive sum of MeFOSAA, PFHxS, PFOA (linear and branched isomers), PFDA, PFUnDA, PFOS (linear and branched isomers), and PFNA in serum or plasma. Caution is warranted when using capillary blood measurements as levels may differ from serum or plasma levels.
Recommendation 5-4: The National Health and Nutrition Examination Survey should begin collecting and sharing more data on children younger than 12 years of age and pregnant people to generate reference populations for those groups.
Recommendation 6-1: Clinicians should treat patients with serum PFAS concentration below 2 nanograms per milliliter (ng/mL) with the usual standard of care.
Recommendation 6-2: For patients with serum PFAS concentration of 2 nanograms per milliliter (2 ng/mL) or higher and less than 20 ng/mL, clinicians should encourage PFAS exposure reduction if a source of exposure is identified, especially for pregnant persons. Within the usual standard of care clinicians should:
Recommendation 6-3: For patients with serum PFAS concentration of 20 nanograms per milliliter (ng/mL) or higher, clinicians should encourage PFAS exposure reduction if a source of exposure is identified, especially for pregnant persons. In addition to the usual standard of care, clinicians should:
Learn More
Per- and polyfluoroalkyl substances (PFAS) are chemicals with almost ubiquitous exposure in the United States. Considering the vastness of this exposure, it is difficult to know who, when, how, and what to test, as well as the risks of testing. This study provides advice for clinicians about PFAS testing and how test results should inform clinical care. Additionally, the expert committee examined the health outcomes associated with PFAS exposure and developed principles clinicians can use to advise patients on exposure reduction.
Read the Report