Per- and polyfluoroalkyl substances, PFAS, are a group of human-made chemicals used in products since the 1940s. Their strong carbon-fluorine bonds provide resistance to heat, oil, and water. This stability means PFAS do not break down easily, leading to their designation as “forever chemicals.” Their persistence has resulted in widespread environmental contamination, particularly in water, raising concerns.
Sources of PFAS Contamination in Water
PFAS enter water systems through several pathways, primarily from industrial activities. Manufacturing facilities release these chemicals directly into air and water through industrial discharges. This includes operations such as chrome plating, electronics manufacturing, and certain textile and paper production.
A significant source of water contamination is Aqueous Film-Forming Foam (AFFF), a firefighting foam used to suppress flammable liquid fires. AFFF has been used at airports, military bases, and industrial sites, leading to PFAS releases into soil and groundwater. Consumer products also contribute as PFAS leach from items like non-stick cookware, stain-resistant fabrics, and grease-resistant food packaging. When disposed of, these products end up in landfills, where PFAS can leach from waste into soil and groundwater, forming leachate. This leachate can then enter wastewater treatment plants, which may not remove PFAS, allowing discharge into rivers or oceans.
Health Considerations of PFAS Exposure
Long-term PFAS exposure through water can lead to potential health effects as these chemicals accumulate in the human body. Research indicates PFAS can interfere with hormones and have been linked to altered immune function, potentially reducing vaccine efficacy in children and increasing infection susceptibility. Studies also suggest impacts on thyroid function, which regulates metabolism, with findings noting higher levels of thyroid-stimulating hormone (TSH) in exposed individuals.
Elevated cholesterol levels, including total and LDL (“bad”) cholesterol, have been associated with PFAS exposure. Liver damage is another concern, with studies showing elevated liver enzymes in individuals with high PFAS blood levels, and research suggesting a link to non-alcoholic fatty liver disease. PFAS exposure has also been linked to reproductive issues like decreased fertility and increased high blood pressure during pregnancy, including preeclampsia. Studies indicate links to certain cancers, specifically kidney and testicular cancers, and developmental effects in children, including small decreases in birth weight. Research is ongoing to understand how different PFAS compounds affect human health.
Detecting PFAS in Water
Detecting PFAS in water presents challenges due to the vast number of compounds and their presence at extremely low concentrations. Specialized analytical techniques are necessary for accurate detection. The most widely used method is Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS), which separates individual PFAS compounds with tandem mass spectrometry for sensitive detection.
This technique allows detection of multiple PFAS compounds in a single analysis, often reaching parts per trillion (ppt) detection limits. While LC-MS/MS is the gold standard for targeted PFAS analysis, other methods like Gas Chromatography-Mass Spectrometry (GC-MS) are used for volatile compounds, and High-Resolution Mass Spectrometry (HRMS) helps identify unknown PFAS. The complexity of PFAS chemistry means laboratory testing requires robust protocols and careful sample preparation for reliable and precise measurements.
Removing PFAS from Water
Technologies effectively remove PFAS from drinking water at municipal treatment plants and household levels. Granular activated carbon (GAC) filtration is an established method. GAC works by adsorbing PFAS compounds onto its highly porous surface, capturing them from the water.
Reverse osmosis (RO) systems use a semipermeable membrane to force water through at high pressure, separating PFAS molecules and other contaminants from purified water. This method is effective for a range of PFAS compounds, including shorter-chain variants. Ion exchange resins offer another solution, where contaminated water passes through specialized beads that attract and hold negatively charged PFAS ions, replacing them with harmless compounds. These resins can have a higher capacity for PFAS removal compared to activated carbon. While effective, their implementation can involve challenges like managing PFAS-containing waste generated during treatment, which requires careful disposal or reactivation.
Regulatory Efforts and Public Information
Government agencies are addressing PFAS contamination in water through various regulatory initiatives. The U.S. Environmental Protection Agency (EPA) has developed health advisories for specific PFAS, such as PFOA and PFOS. In April 2024, the EPA established national, legally enforceable drinking water standards, Maximum Contaminant Levels (MCLs), for six PFAS: PFOA, PFOS, PFNA, PFHxS, HFPO-DA (GenX chemicals), and a mixture limit for four of these.
These regulations, developed under the Safe Drinking Water Act (SDWA), require public water systems to monitor for these and take action if levels exceed the new standards. The EPA’s Unregulated Contaminant Monitoring Rule (UCMR 5) mandates public water systems serving over 3,300 people monitor for 29 PFAS between 2023 and 2025 to gather data on their prevalence. Public health organizations provide guidance to communities, and water systems must inform customers about sampling results through consumer confidence reports.