Chapter Eight: Neurotoxicity of poly- and perfluoroalkyl substances (PFAS): Epidemiological and rodent studies of behavioral outcomes
Poly- and perfluoroalkyl substances (PFAS) are a large class of halogenated organic compounds (HOCs, also called organohalogens) utilized in a variety of industrial applications. Despite their widespread use in bulk quantities, significant concerns have been raised regarding their biological and environmental persistence. In addition, studies have shown some PFAS are reproductive, endocrine, and hepatic toxicants in laboratory animals. Although less is known about potential effects on the nervous system, PFAS are detectable in human cerebrospinal fluid and brain tissue, suggesting they cross the blood–brain and blood–cerebrospinal fluid barriers. Thus, neurotoxicity during development and adulthood is of concern. Here we summarize epidemiological and rodent data regarding the neurotoxicity of PFAS. Specifically, complex indicators of neurological dysfunction related to motor activity, attention/anxiety, and learning and memory are reviewed. Overall, data are mixed; findings vary depending on the congener studied, when the exposure was administered or measured, and the endpoint(s) assessed. However, given the long half-lives of many PFAS and the ubiquity of human exposure, more studies are needed to fully understand how these compounds could interfere with neurobehavior in humans and animal models.