Clinical Evaluation and Management: PFAS Information for Clinicians - 2024

Clinical evaluation and management

When patients have concerns about PFAS or other environmental exposures, clinicians can help address these concerns by actively listening and providing practical advice. Clinicians play an important role in helping patients identify and reduce exposures and in promoting standard age-appropriate preventive care measures for physical health, mental health, and wellness (e.g., Bright Futures and U.S. Preventive Services Task Force recommendations).

No approved medical treatments are available to remove PFAS from the body. Based on information from both a patient's PFAS exposure history and the patient's health history, clinicians can collaborate with patients to develop individualized care plans.

Clinical presentation

PFAS toxicity is not associated with characteristic signs or symptoms. Patients with concerns about PFAS can present with a known exposure and be asymptomatic; they may have signs, symptoms, or a diagnosis of a disease or health issue (e.g., high cholesterol); or they may live in a community with exposure concerns but not know if they were exposed.

Exposure history

The goals of an exposure history are to:

• Identify current and past PFAS exposures,
• Assess the duration, magnitude, and routes of exposure,
• Help patients understand how they have been exposed, and
• Determine if current exposures can be reduced.

A PFAS exposure history asks about the following:

• Documented PFAS contamination in the home, workplace, or community.
• Water, dietary, and consumer product exposure from
  • contaminated drinking water (public water supplies or private well),
  • fish from contaminated water,
  • food wrapped or contained in grease-resistant paper or packaging, and
  • PFAS-containing consumer products (see "Exposure Sources and Routes" section).

• Proximity to places that may manufacture, handle, or use PFAS, such as
  • factories,
  • airports,
  • military bases,
  • wastewater treatment plants,
  • farms where sewage sludge was used for fertilizer,
  • landfills, and
  • incinerators.

• Occupational and recreational exposures to
  • fluorochemical manufacturing processes,
  • firefighting foams,
  • ski wax, and
  • other PFAS-containing materials.
• Past exposures.
• PFAS testing and results (e.g., drinking water or blood test results).
• Prenatal and infancy/childhood exposures, including
  • transplacental exposures, and
  • breastmilk from a person exposed to PFAS or formula mixed with PFAS-contaminated water.

For any identified exposure, it is helpful to seek more detailed information about the route, dose, duration, and frequency of the exposure.

For more information, see ATSDR's educational materials on Taking an Exposure History.

Exposure reduction

An exposure history can inform how to reduce exposure, which is a central goal with any toxic exposure. At this time, it is not possible to eliminate all sources of PFAS exposure. With PFAS, the patient’s exposure might have come from contaminated drinking water or from other sources in their diet, home, or workplace. Local health departments may have information about area PFAS contamination concerns and can often provide additional resources and risk reduction strategies.

^*If monitored, maintained, and used properly, a water filter can reduce PFAS levels. How much PFAS are removed by filtration is determined by the PFAS contaminant levels, the type of filter, and how well the filter is maintained. The global public health organization NSF International has developed a test method to verify a water filter's ability to reduce PFOA and PFOS to below the health advisory levels set by the EPA or individual states. See NSF International's list of approved devices.

For additional steps to reduce exposure, see EPA's Meaningful and Achievable Steps You can Take to Reduce Your Risk.

PFAS blood testing

Systematic, community-wide blood testing can enable public health officials to investigate and respond to community-wide exposures. Results from these tests can assess the types and blood levels of PFAS in the community. (Blood PFAS is the accepted biomarker of exposure for PFAS studies, but some investigations have also included urine testing.)

Clinicians can order PFAS blood levels through CLIA-certified^* commercial clinical laboratories. Results (current levels of PFAS in the blood) could reflect recent exposures or past exposures in the case of PFAS with long half-lives.

In deciding whether to order PFAS testing, clinicians can consider

• an individual's exposure history,
• results of PFAS testing from the patient's water supply, food sources, or other exposure routes, and
• whether results can inform exposure reduction and health promotion.

Benefits of PFAS blood testing might include

• information that could guide exposure reduction,
• greater recognition of PFAS-associated health effects, and
• possible psychological relief from knowing one's PFAS blood level.

Limitations of PFAS blood testing include

• PFAS blood test results do not identify sources of exposure,
• only certain PFAS can be tested in blood and these PFAS might not represent the PFAS to which a patient has been exposed,
• results do not indicate whether a current illness can be attributed to PFAS exposure,
• PFAS blood test results do not predict future health outcomes,
• comparison of PFAS results across laboratories can be difficult (e.g., due to differences in assays used and PFAS tested),
• how long test results remain clinically meaningful is not known, and
• neither the utility of repeat PFAS testing nor the optimum interval for testing is known.

^*For quality assurance, Clinical Laboratory Improvement Amendments (CLIA) regulate laboratory testing and require clinical laboratories to be certified by federal agencies before they can accept human samples.

ATSDR developed a PFAS Blood Level Estimation Tool for community members with exposure to PFAS through drinking water—in particular, for people who would like more information about how this exposure might affect blood PFAS levels. Estimates from this tool might be helpful when discussing potential PFAS exposures with patients.

Clinical management based on PFAS blood levels

Patients and clinicians can discuss the potential risks and benefits of using PFAS blood testing results to guide clinical management. Considerations include

• factors unique to the patient, including the patient's risk for disease,
• whether health screening beyond the usual standards of care is appropriate, and
• the potential for unnecessary further testing and treatment related to false positives from additional screening tests.

ATSDR has not developed health-based screening based on PFAS blood levels and encourages clinicians to follow usual standards of care for health concerns.

For additional consideration, NASEM has proposed health screenings for patients exposed to PFAS based on the sum of certain PFAS (MeFOSAA, PFHxS, PFDA, PFUnDA, PFOS, PFOA, and PFNA) levels.^† Providers who rely on NASEM thresholds for making decisions about further testing can consider that many people in the U.S. will exceed NASEM's proposed thresholds for additional screening. Application of suggested cutoff levels based on PFAS blood testing could create changes in clinical care that differ from current preventive care guidelines.

^†For additional consideration, NASEM has proposed using levels developed by the German Human Biomonitoring (HBM) Commission for PFOA and PFOS. The HBM Commission reviewed studies that did not include cancer as an outcome. NASEM incorporated the European Food Safety Authority (EFSA) methodology that used the sum of PFOS, PFOA, PFHxS, and PFNA to define a risk level and added other PFAS measured by NHANES into the summation. For patients with a sum of blood PFAS levels <2 ng/mL, NASEM recommends the usual standard of care. For blood PFAS levels 2 to <20 ng/mL, they encourage exposure reduction and screening for dyslipidemia, hypertension in pregnancy, and breast cancer. For blood PFAS levels ≥20 ng/mL, they suggest adding the following tests at all well visits: thyroid function testing with serum TSH for patients >18 years; an assessment for signs and symptoms of kidney cancer, including urinalysis, for patients >45 years; and an assessment for signs and symptoms of testicular cancer and ulcerative colitis in patients >15 years. NASEM estimated that for the U.S. population represented by NHANES in 2017–2018, 98% of people had PFAS levels ≥2 ng/mL; 9% had PFAS levels ≥20 ng/mL.

Pregnancy, breastfeeding, and children

Pregnancy – Exposure to PFAS can be associated with pregnancy-induced hypertension, preeclampsia, and small decreases in birth weight. These conditions can occur in many pregnancies, independent of PFAS exposure. Usual prenatal care, including monitoring a patient's blood pressure closely, is appropriate.

Breastfeeding – PFAS can be found in human breast milk. Clinicians can assist patients in deciding whether to breastfeed based on factors specific to the patient and the child. Due to the many benefits of breastfeeding, the Centers for Disease Control and Prevention (CDC) and American Academy of Pediatrics recommend that most nursing people continue to breastfeed. More information on breastfeeding is available at Breastfeeding: Why It Matters.

Children – Studies have reported that exposure to certain PFAS is associated with a slightly lower immune response to some vaccines. The data do not suggest a need to reevaluate the usual immunization schedule (e.g., to repeat vaccinations).