Source and behavior analyses of dioxins based on congener-specific information and their application to Tokyo Bay basin

Identification of pollution sources and estimation of their contribution to dioxin pollution are important for taking better countermeasures against such sources. The information based on seventeen 2,3,7,8-chlorine-substituted congeners and 10 homologues is usually not sufficient for source identification. The usefulness of detailed congener-specific information of tetra- to octachlorinated polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans was examined by principal component analysis and compared with conventional dioxin information. It was revealed that congener-specific information was far more effective for source identification than conventional information. For source apportioning, it was shown that multiple regression analysis with detailed source congener profiles could be carried out successfully when calculations were performed for individual homologues. This was because of the large variation in homologue composition in source dioxin profiles in addition to the difference in environmental behavior among the homologues.