ATSDR's Risk Study Highlights EPA Struggle To Keep Up With PFAS Science

摘要

The Agency for Toxic Substances and Disease Registry's (ATSDR) controversial draft risk estimates for four perflourinated chemicals highlight the struggle EPA faces to keep up with the science for this large class of persistent chemicals emerging as harmful contaminants in many states, says one environmentalist. ATSDR's draft study, which the Trump administration has blocked in the face of opposition from EPA and the Defense Department (DOD). crafted risk estimates for four per- and polyfluoroalkyl substances (PFAS) chemicals, with two resulting in estimates stricter than EPA's and two for which EPA has yet to develop any risk estimates. For perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), ATSDR's proposed minimal risk levels (MRLs) are between seven and 10 times stricter than EPA risk estimates underlying the agency's 2016 drinking water health advisories for those two PFAS. ATSDR's PFOS risk level was stricter than EPA's because it sought to account for immunotoxicity risks, while ATSDR's PFOA assessment relied on a study that was issued weeks after EPA issued its May 2016 risk assessment and health advisory for the substance.