Per- and Polyfluoroalkyl Substances

Abstract

Per- and polyfluoroalkyl substances (PFASs) are a broad group of several thousand xenobiotic chemicals that have been widely used in industrial and consumer applications since the 1940s and are classified as emerging contaminants. The almost ubiquitous presence of PFASs in water, air, sediment, wildlife, and humans at low levels, their extreme persistence, long-range transport potential, and toxic effects has triggered an increasing concern over the potential harm PFASs pose to human health and the environment. PFASs are a very diverse class of chemicals united by the common structural element of a fully fluorinated carbon (alkyl) chain, known as the perfluoroalkyl group. Many PFASs possess terminal ionic functional groups in their structure, which can exist as charged anions, cations, or protonated acids as they can be in differing ionic states. The presence of branched or straight chain isomers in environmental samples is relevant as it may be indicative of the manufacturing process used to synthesize specific PFASs.