Per- and Polyfluoroalkyl Substances (PFAS) and Their Toxicology as Evidenced Through Disease and Biomarkers

Per- and polyfluoroalkyl substances (PFAS) are a group of at least 4730 chemicals with clearly important surfactant properties. They are used in coatings, paints, stain repellents, and firefighting foams as well as other industrial processes. Their high use and recalcitrance to degradation coupled with their lipophilicity and bioaccumulation makes them persistent organic pollutants or forever chemicals. In turn, they are measured in the serum of most humans, especially long-chain PFAS. The toxicity of most PFASs have not been studied, and the USEPA is starting a National PFAS-testing strategy to prioritize PFAS testing because testing all PFASs is not feasible. Some PFASs such as PFOA and PFOS are currently banned in many countries because of their persistence and bioaccumulation. Many PFASs have been observed in the environment and bioconcentrate in aquatic food webs. These chemicals are associated with immunotoxicity, cardiovascular disease, liver disease, reproductive and developmental disorders, and other human health issues.KeywordsPFASFluorosurfactantBioaccumulationPersistencePeroxisome proliferator activated receptors (PPAR)BioconcentrationPFOSPFOAAdverse outcome pathway (AOP)ImmunotoxicityNonalcoholic fatty liver disease (NAFLD)ObesityDevelopmentReproductionMolecular initiating event