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​​​​​​What are PFAS?

Per-and polyfluoroalkyl substances (PFAS) are a group of human-made chemicals that break down slowly in the environment due to their structure and strong chemical bonds. This feature has coined them as “forever chemicals" that are extremely persistent in the environment. PFAS have been widely used throughout the world since the 1940s. Due to their ability to repel oil and water, PFAS are used in many manufactured products, such as nonstick cookware, stain-resistant clothing or fabrics, carpet, food packaging, personal care products, firefighting foams, and more. The two most studied PFAS are perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Examples of other PFAS that have been detected in drinking water and the environment include perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), perfluorobutane sulfonic acid (PFBS), and hexafluoropropylene oxide dimer acid (HFPO-DA).

PFAS enter the body through contaminated food, water, and air, and can remain in the body unchanged for long periods of time. Due to the pervasiveness of PFAS in the environment and their use in many consumer products, it is estimated that over 97% of Americans have PFAS in their blood. Although epidemiological studies are limited, some data suggests that PFAS exposure is linked to increased cholesterol, increased risk of high blood pressure, and decreased vaccine efficacy in children. In animal studies, exposure to PFAS has caused changes in the liver, thymus, and spleen, and has raised concerns about reproductive and developmental consequences. Children may be more sensitive to PFAS exposure due to their developmental stage, and the amount of food, water, and air they consume and breathe relative to their body weight.  

The PA Department of Environmental Protection (DEP) published final-form rulemaking on January 14, 2023, that established regulatory maximum contaminant levels (MCLs) for PFOA (14 parts per trillion or ppt) and PFOS (18 ppt) in PA drinking water. Due to this regulation and testing requirements that started in the first quarter of 2024, many water systems, including those that serve school buildings, were testing for PFOA and PFOS for the first time. A DOH developed a PFAS FAQ for schools​ ​to answer frequently asked questions specific to schools and child exposures.

On April 10, 2024, the Environmental Protection Agency (EPA) released a new set of MCLs for five individual PFAS chemicals (including PFOA, PFOS, PFNA, PFHxS, and HFPO-DA) and a PFAS mixture. The EPA standards are lower and supersede those that were put into place by the PA DEP. The new MCLs are: 4.0 ppt for PFOA and PFOS, 10 ppt for PFNA, PFHxS, and HFPO-DA, and 1 hazard index for the PFAS mixture of PFNA, PFHxS, HFPO-DA, and PFBS. For more information on PFAS and the new standards, view the PA DOH PFAS fact sheet.​

PFAS Projects

Pennsylvania PFAS Multi-site Health Study (PA PFAS MSS)

PADOH is working with Research Triangle Institute (RTI) International in administering a national health study involving PFAS exposure. Temple University and Brown University are also partners in this study which is being funded by the Centers for Disease Control and Prevention (CDC) and its sister organization, the Agency for Toxic Substances and Disease Registry (ATSDR.) The study specifically examines the health of residents exposed to PFAS through their drinking water in Horsham, Warrington and Warminster areas in Bucks and Montgomery Counties.

The PA PFAS Multi-site Study is collecting information on health conditions, including autoimmune disorder, cancer, diabetes, heart disease, immune response, kidney and liver function, osteoarthritis, thyroid conditions, and in participants ages 5-17, neurobehavioral conditions.

For more information, please visit the study website.

PFAS Exposure Assessment Technical Tools (PEATT) Pilot Project

During summer of 2018, DOH tested a toolkit created by the CDC and ATSDR to perform blood tests on residents living in communities exposed to perfluoroalkyl and polyfluoroalkyl substances (PFAS) in their drinking water. This project is funded by the Association of State and territorial Health Officials (ASTHO) and allow DOH to give feedback on improving the process for a larger, national study.

The initial project is completed and the preliminary results of the study can be found in the PEATT Project Final Report.

In the summer of 2019, DOH conducted additional exposure assessments on our original PEATT pilot project participants. As part of this, DOH tested urine samples from the participants. DOH also tested dust and tap water samples from 10% (14) of our study households. The purpose of this environmental assessment was to examine other sources of PFAS exposure beyond drinking water. Please see the webinar and the report below for the results of these additional testing.

PEATT Project Documents

PFAS Reference Documents