PFAS

PFAS, or per- and polyfluoroalkyl substances, are a large and diverse class of synthetic fluorinated chemicals. They are defined by strong carbon–fluorine bonds that confer stability and resistance to heat, water, and oil. Thousands of PFAS exist, with notable examples such as PFOA, PFOS, PFHxS, PFNA, and GenX (HFPO-DA). PFAS can persist for long periods in the environment and in living organisms, and exposure can occur via multiple pathways.

PFAS are persistent in air, soil, and water and can move through ecosystems. They tend to be highly stable and resistant to degradation, yet some can accumulate in organisms to varying degrees. Humans can be exposed through drinking water, contaminated food, consumer products, and occupational settings, among other pathways.

They have been used since the mid-20th century in a wide range of products and processes, including non-stick cookware, water- and stain-repellent fabrics and textiles, food packaging, firefighting foams, coatings, and certain industrial applications. Their utility arising from low surface tension and resistance to heat and chemicals contributed to widespread use.

Health and regulatory considerations: Certain PFAS have been linked to adverse health effects in humans, including immune, hormonal, developmental, and metabolic endpoints, with some associations to cancer in specific compounds. Risk depends on the particular PFAS and the level and duration of exposure. Regulatory approaches vary by jurisdiction and compound, with many agencies issuing drinking-water advisories or enforceable limits and international efforts restricting or phasing out certain PFAS.

Remediation and management: Removing PFAS from contaminated water is technically challenging. Common treatment options include activated carbon, ion-exchange resins, and membrane processes, often used in combination. Prevention, source control, and continued monitoring are key components of management.

Research and outlook: Ongoing work aims to improve detection, risk assessment, and treatment, and to identify safer substitutes for industry.