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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

How does PFAS Get into the Environment?

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:

  • Fluorochemical manufacturing sites release PFAS into water and into the air
  • PFAS-containing foams are sprayed at military sites and commercial airports in training exercises for firefighters
  • PFAS can leak from landfills where PFAS-containing waste is disposed
Figure. PFAS contamination can be found where PFAS is made, used, disposed of, or spilled. PFAS contamination is likely near facilities that use or have used fluorochemicals, commercial airports, military bases, wastewater treatment plants, farms where sewage sludge may have been used, or landfills or incinerators that have received PFAS-containing waste.

How does PFAS Get into Drinking Water?

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).

Where is PFAS contamination found in the United States?

In the United States, an estimated 2,854 locations across the 50 states and two territories have some level of PFAS contamination.

Figure. PFAS Contamination Across the United States.
SOURCE: Environmental Working Group (EWG). Learn more about this figure.

When was PFAS contamination discovered?

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.

Why wasn’t PFAS contamination identified sooner?

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

How are people exposed to PFAS?

PFAS exposure is highly complex and can take varied paths:

  • These include work in fluorochemical manufacturing facilities, work in facilities where PFAS containing products such as textiles or food contact materials are made, electroplating, paint, carpet installation and treatment, military and civilian firefighters who use PFAS containing foams in training exercises and wear PFAS impregnated gear, and jobs that require prolonged work with ski wax.
  • Ingestion is the primary route of exposure for those not exposed through their work. This may include drinking PFAS-contaminated water or eating foods such as vegetables, game, or dairy products grown in contaminated soil or water. Exposure may also occur when dust containing PFAS is ingested.
  • PFAS can transfer to the fetus during pregnancy, and in early life during lactation. While PFAS can pass through breast milk from mother to baby, research has consistently shown benefits of breastfeeding even while PFAS exposures have been occurring for many years. PFAS may also be present in water used to reconstitute formula and potentially in packaged formula and baby food.
  • PFAS are used in thousands of products including water- and stain-resistant clothing and personal care products such as sunscreen, makeup, and dental floss. Other product uses including paint, climbing ropes, guitar strings, and artificial turf.
  • PFAS are often used in food contact materials such as microwave popcorn bags or packaging of fast foods or processed foods.

How long do PFAS stay in the body following exposure?

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.

  • Start with a conversation with your doctor for how you might be exposed to PFAS, including at work. Unfortunately, it can be there are not many well-documented behavior changes that we know will reduce your exposure.
  • If PFAS are in your local drinking water, switching to consumption of water lower in PFAS – for example, filtered water – will reduce exposure. The report points to a database created by NSF International to help patients locate water filters that can reduce PFAS.

POTENTIAL HEALTH EFFECTS OF PFAS

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.

Evidence table view larger

GUIDANCE FOR CLINICAL CARE

Advising Patients about PFAS Exposure

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:

  1. talk with their patients to determine how they might be exposed to PFAS;
  2. advise that those with occupational exposure to PFAS consult with occupational health and safety professionals about reducing exposure;
  3. advise individuals with elevated PFAS in their drinking water to filter their water, or find drinking water source with lower levels of PFAS;
  4. advise patients living in areas of known PFAS contamination that PFAS can be present in fish, wildlife, meat, and dairy.

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.

PFAS Blood Testing

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:

  1. How PFAS exposure occurs, potential health effects of PFAS, limitations of PFAS testing, and the harms and benefits of PFAS testing
  2. That exposure biomonitoring may provide important information about an individual's exposure levels, which might guide clinical follow-up for diseases and conditions associated with increased risk from PFAS exposure
  3. That testing information cannot indicate or predict how likely it is that an individual will end up with a particular condition

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:

  • How people can be exposed to PFAS: Occupational exposures, work with fluorochemicals, or as a firefighter. Consumption of contaminated drinking water can occur in communities that obtain their water from sources near commercial airports, military bases, fluorochemical manufacturing plants, wastewater treatment plants, landfills, or incinerators where PFAS containing waste may have been disposed of or farms where sewage sludge may have been used. Consumption of contaminated fish or game if fishing or hunting occurs in contaminated areas. Individuals living near fluorochemical plants may also be exposed via inhalation of air emissions.
  • Potential health effects of PFAS exposure (Chapter 3) and strategies to reduce exposure (Chapter 4)
  • Limitations of PFAS blood testing: PFAS blood testing does not identify the sources of exposure or predict future health conditions. PFAS blood testing only assesses body burden at the time of sample collection. For example, a person with low blood levels today may have had higher exposure in the past.
  • The benefits and harms of PFAS testing (Box 5-2).

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:

  • Had occupational exposure to PFAS (such as those who have worked with fluorochemicals or worked as a firefighter),
  • Lived in communities where environmental and public health authorities (CDC, ATSDR, EPA, state and local environmental or health authorities), or academic researchers, have documented PFAS contamination,
  • Lived in areas where PFAS contamination may have occurred, such as near facilities that use or used fluorochemicals, commercial airports, military bases, wastewater treatment plants, farms where sewage sludge may have been used, or near landfills or incinerators have received PFAS containing waste.

Patient Follow-Up after PFAS Testing

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.

PFAS exposure [ view larger]

Flow Chart of Clinical Care

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.

Flow chart of clinial care [ view larger]

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:

  • Adverse health effects related to PFAS exposure are not expected at less than 2 nanograms per milliliter (ng/mL).
  • There is a potential for adverse effects, especially in sensitive populations, between 2 and 20 ng/mL.
  • There is an increased risk of adverse effects above 20 ng/mL.

* 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:

  • Prioritize screening for dyslipidemia with a lipid panel (once between 9 and 11 years of age, and once every 4 to 6 years over age 20) as recommended by the American Academy of Pediatrics (AAP) and American Heart Association (AHA).
  • Screen for hypertensive disorders of pregnancy at all prenatal visits per the American Congress of Obstetricians and Gynecologists (ACOG).
  • Screen for breast cancer based on clinical practice guidelines based on age and other risk factors such as those recommended by the U.S. Preventive Services Task Force (USPSTF).

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:

  • Prioritize screening for dyslipidemia with a lipid panel (for patients over age 2) following American Academy of Pediatrics (AAP) guidelines for high-risk children and American Heart Association (AHA) guidance for high-risk adults.
  • At all well visits:
    • conduct thyroid function testing (for patients over age 18) with serum thyroid stimulating hormone (TSH),
    • assess for signs and symptoms of kidney cancer (for patients over 45), including with urinalysis, and
    • for patients over 15, assess for signs and symptoms of testicular cancer and ulcerative colitis.

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