At a Glance Drinking water samples from 43 out of 44 tested cities contained PFAS.The highest levels were found in Brunswick County, North Carolina.PFAS have been shown to cause health problems in humans. Toxic "forever chemicals" known as perfluoroalkyl substances, or PFAS, have been found in the drinking water of dozens of U.S. cities. Some of the highest PFAS levels detected were , including Miami, Philadelphia, New Orleans and Bergen County, New Jersey, according to a study from the Environmental...