Per- and polyfluoroalkyl substances (PFAS) are a vast group of synthetic chemicals manufactured and used in industry and consumer products since the 1940s. These compounds are characterized by a strong carbon-fluorine bond, making them extremely resistant to environmental degradation, earning them the nickname “forever chemicals.” PFAS are found in countless products due to their ability to repel grease, water, and stains, appearing in items like nonstick cookware, waterproof clothing, and firefighting foams. Because they do not break down easily, PFAS have become ubiquitous, contaminating soil, air, water, and accumulating in the tissues of living organisms, including humans, which is why testing for their presence has become a public health priority.
Why PFAS Testing Is Essential
PFAS testing is essential due to the unique chemical properties and widespread distribution of these substances. PFAS are persistent, remaining intact in the environment for extensive periods and traveling long distances to contaminate resources like drinking water. This persistence leads to bioaccumulation, where the chemicals build up in the body over time because they are not readily excreted.
Scientific studies suggest that exposure to certain PFAS is associated with a range of adverse health outcomes. These documented links include an increased risk of some cancers, such as kidney and testicular cancer, as well as impacts on the immune system, leading to a reduced response to vaccines. Other health concerns linked to PFAS exposure are developmental delays in children, liver damage, and changes in cholesterol levels.
Testing is the fundamental tool used by regulators and public health officials to assess contamination, quantify risk, and ensure compliance with safety standards. Testing provides the data necessary for risk assessment, allowing authorities to determine if the levels of these chemicals in a specific area exceed established health guidelines. By identifying the sources and extent of contamination, testing informs decisions about remediation efforts and the implementation of water treatment technologies. The information gathered is instrumental in protecting both human health and ecological systems from the long-term consequences of these highly mobile and enduring pollutants.
Diverse Sample Types Subject to Testing
PFAS testing is conducted on a wide variety of sample types, reflecting the diverse pathways through which exposure occurs. Environmental testing focuses on sources of exposure or reservoirs of contamination, with drinking water being a primary concern due to its direct path to human consumption. Groundwater, surface water, and wastewater are regularly analyzed to track the movement of PFAS from industrial sites, landfills, and wastewater treatment plants.
Solid environmental samples, such as soil, sediment, and biosolids (treated sewage sludge), are frequently tested to understand long-term contamination at specific sites, like military bases or manufacturing facilities. Analyzing these solid samples helps determine the extent of localized pollution, especially where firefighting foams containing PFAS were used. Air samples are sometimes analyzed to measure exposure through inhalation near manufacturing plants.
Biological monitoring involves testing human and animal samples to determine the total amount of PFAS accumulated in an organism. Human blood serum or plasma is the most common biological sample tested, as it provides a measure of the individual’s long-term exposure to the most persistent PFAS. Testing blood helps clinicians and researchers estimate exposure levels and correlate them with potential health effects. Urine samples can also be analyzed, often to measure the levels of shorter-chain PFAS or those that are more readily excreted by the body.
How Laboratories Detect and Measure PFAS
The process of detecting and measuring trace levels of PFAS requires specialized laboratory techniques and rigorous quality control. The analytical process begins with meticulous sample preparation, which is designed to isolate and concentrate the minute quantities of PFAS present in the matrix while minimizing the risk of contamination. For water samples, this often involves Solid Phase Extraction (SPE), where the water is passed through a cartridge to trap the PFAS compounds.
The concentrated sample extract is then analyzed using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS), which is considered the gold standard for this type of trace analysis. The Liquid Chromatography (LC) component separates the complex mixture of PFAS compounds based on their chemical properties. The Tandem Mass Spectrometry (MS/MS) component then identifies and quantifies each separated compound by measuring its unique mass and fragmentation pattern.
Laboratories adhere to standardized methods published by regulatory bodies to ensure reliable and comparable results. For drinking water, the United States Environmental Protection Agency (EPA) methods 537.1 and 533 are commonly used, with each method targeting a specific list of PFAS compounds. For non-drinking water samples like soil, sediment, and tissue, the comprehensive EPA Method 1633 is employed, measuring a broader suite of analytes. These methods incorporate strict Quality Assurance/Quality Control (QA/QC) procedures, including the use of isotopically labeled internal standards, to account for matrix effects and potential contamination throughout the entire analytical workflow.
Understanding and Responding to Test Results
Interpreting PFAS test results requires understanding technical terms and the context of regulatory standards. The Limit of Detection (LOD) represents the smallest concentration of a substance that an analytical method can reliably distinguish from the absence of the substance. Results are often compared against regulatory Action Levels or Maximum Contaminant Levels (MCLs), which are legally enforceable standards set by federal or state agencies for public water systems.
The EPA has established final MCLs for certain individual PFAS, such as Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonic Acid (PFOS), at extremely low parts-per-trillion levels. In cases where a single compound is not regulated, a Hazard Index approach may be used, which considers the combined risk of a mixture of multiple PFAS compounds present in the sample. When a test result indicates a level above a state or federal guideline, it triggers a mandatory response and public notification for a public water system.
For individuals with high levels of PFAS detected in their private drinking water, installing a certified in-home filtration system is an effective mitigation strategy. Effective options include granular activated carbon (GAC) filters and reverse osmosis (RO) systems, which significantly lower chemical concentrations. Individuals can also consider using an alternate source of water for drinking and cooking until the contamination is resolved. Source remediation, involving the cleanup of the contaminated area, is a broader, long-term response typically undertaken by responsible parties or government agencies.