ISOMER SPECIFIC - DETERMINATION AND TOXIC EVALUATION OF POLYCHLORINATED BIPHENYIS, POLYCHLORINATED BROMINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS, POLYBROMINATED BIPHENYL ETHERS, AND EXTRACTABLE ORGANIC HALOGEN IN CARE FROM THE BUFFALO RIVER, NEW-YORK

Concentrations of PCB isomers, polychlorinated/brominated dibenzo-p-di oxins (PCDDs/PBDDs) and dibenzofurans (PCDFs/PBDFs), polybrominated bi phenyl ethers (PBBEs), and total extractable organic halogen (EOX) wer e determined in carp (Cyprinus carpio) of three age classes collected from the Buffalo River, New York. Total PCBs concentrations exceeded t he United States Food and Drug Administration's tolerable level of 2 m u g/g (wet wt) in all the three age classes. Concentration ranges of t otal PCDDs and PCDFs were 27-146 and 22-99 pg/g, respectively. Among s everal of the 2,3,7,8-substituted isomers detected, OCDD and OCDF were the most predominantly noticed congeners. Noticeable concentrations o f PBBEs were found with a major contribution from tetra-BBEs. Extracta ble organochlorines (EOCI) were the highest in the total EOX family fo llowed by organobromines and organoiodines. The known organochlorines such as PCBs and DDT accounted for 13-58% of the EOCI, suggesting the presence of considerable levels of other unknown organochlorines. The 2,3,7,8-TCDD equivalents of coplanar PCBs, dioxins, and furans in carp muscle were between 45 and 108 pg/g, with 38-48% of the toxicity exer ted by mono-ortho-PCBs. The estimated allowable con- sumption rates of carp based on the risk assessment method were much lower than the act ual consumption values available for the Great Lakes states. Elevated concentrations of PCB isomers other than dioxins and furans suggest th e need to protect humans from the consumption of PCB-contaminated carp from the Buffalo River.