A NATIONAL STUDY OF CHEMICAL RESIDUES IN FISH .3. STUDY RESULTS

Bottom feeding and game fish, from each of nearly 400 sites throughout the United States were analyzed for 15 PCDD/PCDFs, PCBs, 21 pesticides and herbicides, and 13 other organic chemicals, and mercury. Seven of the PCDD/PCDFs and 15 of the other chemicals were detected at over 50 percent of the sites. PCBs were detected at 91% of all sites at a mean concentration of 1.90 mug/g, and exceeded 10 mug/g at 10 sites. 2,3,7,8-TCDD was detected at 70 percent of the sites at a mean concentration of 6.9 ppt and a maximum concentration of 204 ppt. 2,3,7,8-TCDF was detected at 89 percent of the sites at a mean concentration of 13.6 ppt and a maximum concentration of 404 ppt. Fish from 75% of all sites had a total TCDD toxic equivalence concentrations (TEC) due to PCDD/PCDFs, below 10 pg/g. Those with the highest 2,3,7,8-TCDD concentrations also had the highest TEC. p,p1-DDE was the most frequently detected individual analyte (99% of samples), and was found at the highest maximum (14,000 ng/g) and mean (295 ng/g) concentrations. No correlation between specific sources and most of the analytes could be made. However, pulp and paper mills using chlorine appear to be a significant source of 2,3,7,8-TCDD and 2,3,7,8-TCDF in these samples which were collected between 1986 and 1989.