You are here:
EXAMINATION OF DECHLORINATION PROCESSES AND PATHWAYS IN NEW BEDFORD HARBOR SEDIMENTS
Citation:
Lake, J., R. Pruell, AND F. Osterman. EXAMINATION OF DECHLORINATION PROCESSES AND PATHWAYS IN NEW BEDFORD HARBOR SEDIMENTS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-94/001 (NTIS PB94140795).
Description:
Estuarine sediments from upper New Bedford Harbor, Massachusetts, which were heavily contaminated with polychlorinated biphenyls (PCBs), showed considerable compositional alterations of PCB residues relative to mixtures of Aroclor 1242 and 1254 standards, and PCB distributions present in sediments from lower New Bedford Harbor and Black Rock Harbor, Connecticut. he compositional alterations, which presumable resulted from reductive dechlorinations by bacteria, became more extensive with increasing PCB concentration and decreasing distance from the suspected PCB source, an electrical capacitor manufacturing plant. hree pathways which removed chlorine substituents from specific locations on PCB molecules were responsible for most of the observed dechlorinations. onsiderable differences were found in the extent of dechlorination within sediment cores and between sampling sites in upper New Harbor. he most extensively altered PCB distribution was found in the 15-17.5 cm deep section of a core from nearest to the plants outfall. n most cores, less altered PCB residues were found in the 0-2.5 and 5-7.5 cm core sections than in the 15-7.5 cm section. arge variations in estimates of dechlorination rates were found, depending on the sample and the congener. he dechlorination processes found may decrease the potential toxicity and bioaccumulation potential of the PCB residues in these sediments.