Distribution and Characterization for Dioxins in River Water and Sediment of Osaka Prefecture

Distributions for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs), and Co-PCBs in river waters and sediments at 36 points in Osaka Prefecture were investigated. Total PCDD/PCDFs concentrations of waters were ranged in 0.076 1.8 pg-TEQ/l (0.50 pg-TEQ/l in average) . Those of sediments were ranged in 0.18-510 pg-TEQ/g (27 pg-TEQ/g in average) . The average constituent ratio of water concentration in TEQ were arranged in a magnitude of PCDDs>PCDFs>Co-PCBs for Yodo rivers and Sensyu rivers, and those were arranged in PCDFs>PCDDs>Co-PCBs for Kanzaki rivers, Neya rivers and Yamato rivers. The ratios in river sediments were in order of PCDDs>PCDFs>Co-PCBs for all of rivers except Sensyu rivers (PCDFs > PCDDs > Co-PCBs) . Homologue profiles for PCDD/PCDFs in water and sediment from all rivers were similar with each other. TeCDFs through OCDFs and TeCDDs homologues showed larger reagional variation than other homologues in both waters and sediments. Average constituent ratios of Co-PCBs congeners for river waters were in order of #118 (48%) >#105 (22%) >#77 (14%) > #156 (5.5%) and thus congener profiles were observed in all water regions. In addition, the similar profiles were recognized for river sediments. A principal analysis for PCDD/PCDFs constituent ratios of river waters, sediments, ambient airs (vapor-phase and paraticle-bound), exhaust gases from incinerators and agrochemicals such as PCP and CNP was perfomed. Component 1 was supposed from combustion for positive and from agrochemicals (PCP) for negative, showing to be 38 % in contribution percentage. Component 2 was from particulate matter of PCDD/PCDFs for positive and vapor phase of PCDD/PCDFs for negative, with a contribution of 27 %. Component 3 and component 4 showed contributions of 13 % and 12 %. and the cumulative value of components 1-4 was in 90 %.