Sources and distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans in sediments from Masan Bay, Korea.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs) were measured in sediments collected from Masan Bay, Korea. Almost all tetra- through octachlorinated PCDDs/DFs were identified, including the 17 2,3,7,8-substituted PCDDs/DFs. Total concentrations of PCDDs/DFs in sediments ranged from 102 to 6,493 pg/g dry weight. Concentrations of 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TeCDD) equivalents (TEQs) in sediments estimated based on I-TEFs were in the range of 1 to 76 pg/g dry weight. Total concentrations of PCDDs/DFs in Masan Bay sediments were comparable to those reported for the Rhine and Humber Rivers on the North Sea, the Housatonic River in the United States, and some rivers and lakes in Japan and the United Kingdom. A spatial gradient of total concentrations of PCDDs/DFs decreased toward the open sea. Two of the 11 sampling sites near the coastal zone contained relatively great concentrations, suggesting the presence of point sources. The homologue composition of PCDFs in sediments from two highly contaminated locations in Masan Bay was correlated with that of commercial polychlorinated biphenyl (PCB) preparations, such as Kanechlors 300, 400, or 500. The wide range of PCDD isomers and greater concentrations of PCDDs than of PCDFs at certain locations suggest that, in addition to technical PCB preparations such as Kanechlors, other sources, like solid waste incineration, uncontrolled trash burning, and pentachlorophenol, have contributed to the contamination.