Editor’s note: This story was updated on Feb. 5, 2024, to include information on an Environmental Protection Agency proposal to add nine per- and polyfluoroalkyl compounds to its list of “hazardous constituents.”
The Centers for Disease Control and Prevention and Agency for Toxic Substances and Disease Registry (ATSDR) have provided updated guidance for clinicians to consider when caring for patients who have concerns about exposure to per- and polyfluoroalkyl substances (PFAS).
The resource, published Jan. 18, is the first update to PFAS clinical information since 2019. It discusses the evolving science and emphasizes the importance of patients and clinicians working together to address patients’ concerns and reduce exposures to PFAS, which sometimes are called “forever chemicals” because they do not break down easily.
The update provides information for clinicians on:
- exposure sources and routes;
- health effects associated with PFAS exposures and factors that impact the risk of health effects;
- considerations for clinical evaluation and management, including information on the benefits and risks of PFAS blood testing; and
- considerations for certain populations, such as children and those who are pregnant or breastfeeding.
Additionally, the Environmental Protection Agency announced a proposal on Jan. 31 to add nine PFAS compounds, their salts and their structural isomers to its list of “hazardous constituents” under the Resource Conservation and Recovery Act. The nine PFAS are perfluorooctanoic acid, perfluorooctanesulfonic acid, perfluorobutanesulfonic acid, hexafluoropropylene oxide-dimer acid, perfluorononanoic acid, perfluorohexanesulfonic acid, perfluorodecanoic acid, perfluorohexanoic acid and perfluorobutanoic acid.
To be listed as a hazardous constituent, scientific studies must show the chemical has toxic, carcinogenic, mutagenic or teratogenic effects on humans or other life forms. The EPA will collect comments on the proposal for 60 days once it is published in the Federal Register.
Communities around the United States have been concerned about possible health effects from exposure to PFAS. The main route of PFAS exposure is through ingestion of contaminated food and water.
Health effects that may be associated with PFAS exposure include increases in cholesterol levels, decreases in birth weight, lower antibody response to vaccines, kidney and testicular cancer, pregnancy-induced hypertension, preeclampsia and changes in liver enzymes.
The new information provides clinicians with resources to help counsel and support those who may face PFAS exposure. Clinicians should work with patients to identify and reduce PFAS exposures and promote standard age-appropriate preventive care measures for physical health, mental health and wellness (e.g., Bright Futures recommendations).
Clinicians should ask about possible current and past PFAS exposure sources, durations, frequency and magnitude.
Exposure reduction strategies can include installing a water filtration system or using an alternative water source; limiting or avoiding consumption of contaminated fish, meat, eggs or dairy; and choosing products without PFAS, when possible.
PFAS are a family of thousands of synthetic chemicals that contain a partially or fully fluorinated carbon chain. Their chemical properties allow them to reduce friction and resist oil and water. As a result, they have been used widely in industry and consumer products since the 1940s, including nonstick cookware, stain-resistant carpeting, ski wax, dental floss, commercial firefighting foams and food packaging.
PFAS are widespread and persistent in the environment, and have been detected in drinking water, house dust and foods like fish, meat and dairy products. The carbon-fluorine bonds are strong, so these compounds do not fully break down in the environment or human body.
In humans, properties of the most well-studied PFAS include:
- Absorption: Absorbed in the intestines and lungs; limited dermal absorption;
- Distribution: Bind to serum proteins; to a lesser extent, bind to tissue proteins (e.g., liver, kidneys and brain);
- Metabolism: Most not metabolized; some metabolized to other PFAS;
- Elimination: Mainly in urine (clearance rate can vary by sex and kidney function); also through defecation, menstruation, breastfeeding and placental transfer; and
- Half-life: A few days to eight years or more.
The report includes links to additional clinical resources and information to assist providers and patients. ATSDR will continue to review the science and periodically update this information for clinicians.
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