Fish products consumed by Americans are treated with dangerous chemicals China, the leading exporter of seafood to the U.S., is raising most of its fish products in water contaminated with raw sewage and compensating by using dangerous drugs and chemicals, many of which are banned by the Food and Drug Administration. FDA inspectors report tainted food imports from China are being rejected with increasing frequency because they are filthy, contaminated with pesticides and tainted with carcinogens, bacteria and banned drugs.