PFAS are persistent chemicals – this means that they do not break down when exposed to air, water, or sunlight; they build up over time in the environment and the human body. Studies have found PFAS to have potentially harmful effects in people and animals. Due to the widespread presence of these chemicals in people’s daily lives around the globe, governments are acting to address PFAS contamination and protect the public.

Researchers are actively working to learn the full extent to which PFAS impacts human health. However, there has been extensive research done on the health implications of the most prevalent PFAS, primarily PFOS and PFOA. While more research is needed, and studies do not have absolute consistency across the board, the most common effects associated with higher levels of PFAS in the blood are increased levels of cholesterol, liver enzymes, and uric acid. In addition, there is evidence to suggest PFAS could lower the immunization ability of vaccines and hinder developmental and hormonal growth. Studies that exposed high levels of PFAS to animals found the chemicals to negatively impact fertility, development, the immune system, and the liver. These animals also had a greater risk for cancer. While this research can help predict how PFAS will affect human health, it should be noted that the animals in these studies were exposed to much higher levels of PFAS than typical human exposure. ​

The U.S. Environmental Protection Agency (EPA) has established a lifetime health advisory level for PFOS, PFOA, PFBS, and HFPO-DA (Gen X). EPA's health advisories are non-enforceable and non-regulatory and provide technical information to state agencies and other public health officials on health effects, analytical methodologies, and treatment technologies associated with drinking water contamination.

In 2023, Pennsylvania’s PFAS MCL Rule was published in the Pennsylvania Bulletin, setting maximum contaminant levels (MCLs) for PFOS and PFOS in drinking water in Pennsylvania. The MCLs are set at 14 ppt for PFOA and 18 ppt for PFOS and apply to all public water systems in Pennsylvania. MCLs are enforceable standards.

Under authority of the Pennsylvania Safe Drinking Water Act and regulations, DEP may, on a case-by-case basis, take corrective actions against public water systems when an unregulated contaminant is present and creates a risk to public health. As per long-standing protocol, DEP uses the EPA's health advisory levels to determine what unregulated chemicals pose a risk to public health.

PFAS are found in many household and industrial products. Due to their resistant properties, they are commonly used in coatings to make items more durable.

PFAS have been found in:

• Non-stick cookware
• Toiletry items
• Food containers (such as fast food and candy wrappings, pizza boxes, and microwave popcorn bags)
• Waterproof and stainproof clothing, furniture, and carpets
• Fire-fighting foams
  Chemical reaction-resistant coatings used in industrial processes
  

PFAS are manmade chemicals, meaning they do not occur naturally in the environment. However, their widespread use has resulted in PFAS being present in the environment and populations around the world. Research estimates that low levels of PFAS are in about 98% of Americans. Most Americans are exposed to PFAS through ingestion; this is a result of their use in common food-related and cooking products.

There are several locations under investigation where individuals are exposed to higher levels of PFAS than Pennsylvania’s MCLs for PFOA or PFOS, or the EPA’s health advisory levels for other PFAS. In these cases, PFAS have contaminated the public water supply or an individual’s private well at a level that poses potential health risks. These chemicals typically enter the water supply when material containing PFAS is used or spilled in the natural environment. When these high levels of PFAS are released, they leak into lakes and rivers or permeate the surface to enter groundwater resources. Consequently, certain areas where industrial activity or spills involving PFAS have taken place are at risk for contaminated drinking water. The most common sites for contamination are factories manufacturing with PFAS, firefighting training locations, military bases, and airports.

It should be noted that direct skin contact is not the primary form of exposure for PFAS and is not a serious health concern ; it is safe to bathe, swim, and otherwise touch PFAS-contaminated water. More information about PFAS exposure and health recommendations can be found on the ATSDR’s website.​