For almost six years, Dr. Scott Bartell has been investigating the effects that per- and polyfluoroalkyl substances (PFAS) have on the health of Orange County residents after high levels of PFAS were detected in drinking water supplies. … Bartell says some of the results from the UCI study contradict previous findings on PFAS health. “We have some findings on obesity, which is one of the endpoints people have been wondering about, PFAS might be an obesogen and then cause more weight gain if people are exposed,” Bartell said. “But we’re not actually seeing that.”