Abstract
Time trend analyses of PCDDs/DFs and PCBs in sediments in background area and urban/industrial areas were performed . PCDDs/DFs concentrations increased mainly in 1960s in the whole country . The sources of PCDDs/DFs in Lake Biwa and Osaka Bay were considered to be due to multiple pollution from combustion sources and organic chemicals such as PCP and CNP . PCBs trends of sediment cores of industrial areas were similar to the trend of commercial PCBs production and usage. From congener patterns of Co-PCBs, it was suggested that the sources of PCBs in industrialareas were due to commercial PCBs and pollution spread out via atmospheric and water transport. Comparison among the sedimentation fluxes indicated that the accumulation of contaminants to lacustrine area occurred, and characterized the contamination level in urban/industrial areas.
