In vivo toxicity testing – PFAS BOSC Meeting

This is a high-level overview presentation of ORD in vivo PFAS toxicology research and there is no associated abstract.

Impact/Purpose

Per- and poly-fluoroalkyl substance (PFAS) health effects is a critical research area due to issues associated with environmental persistence, widespread occurrence, biological half-life, toxicity, and nearly ubiquitous human and environmental exposure.  Research toxicologists in EPA/ORD are conducting in vivo experiments to advance the scientific understanding of how PFAS exert toxic effects, primarily associated with exposure during pregnancy, and generate data for understudied PFAS and PFAS mixtures to potentially inform risk assessment and regulatory actions.  Studies reviewed in this presentation largely focus on oral maternal exposure during pregnancy in laboratory rats.  Studies include experiments with PFOA, PFOS, PFHxS, GenX, Nafion byproduct 2, PFMOAA, and PFAS mixtures.  A broad range of endpoints were investigated including body weights, organ weights, pup viability, organ histopathology, tissue specific gene expression, serum clinical chemistry, serum thyroid hormone levels, serum and organ concentrations of test chemical, and functional tests of neurodevelopment.  High content approaches including target tissue transcriptomics and serum targeted metabolomics have also been conducted.Numerous major observations have been made by ORD toxicologists including dose-response characterization of GenX, Nafion byproduct 2, and PFMOAA as developmental toxicants, demonstration of additive effects from combined exposure to multiple PFAS, characterization of serum and brain thyroid hormone concentrations from PFHxS exposure and relationship to functional neurotox endpoints, and elucidation of multiple key events critical to describing PFAS AOPs.The data from these projects are currently or will be highly useful to USEPA Program Offices, State health-based agencies, and International regulatory bodies in their efforts to evaluate and characterize risk and pursue regulatory actions for individual PFAS and PFAS mixtures.        

Citation

Conley, J. In vivo toxicity testing – PFAS BOSC Meeting. EPA Board of Scientific Counselors (BOSC) - PFAS Meeting, NA-Virtual, NC, September 29 - 30, 2021.