EWG researchers calculated that eating one fish in a year equated to ingesting water with PFOS at 48 parts per trillion, or ppt, for one month. National EPA tests, from which the calculations were drawn, show nearly all fish in U.S. rivers and streams are contaminated with PFAS in the parts-per-billion range – even greater than parts per trillion. Although the most recent test results found decreasing PFAS levels, freshwater fish are still contaminated at high levels and pose a significant public health risk. (January 17, 2023)