PT07 Contaminated Harbor and River Sediment
Exhibit Hall
8:00 AM - Tuesday, 11 November 2003
(PT123) Distribution and Fate of PCDD/Fs and Dioxin-like PCBs in Seawater in the Tokyo Bay, Japan.
Kobayashi, N1, Masunaga, S1, Nakanishi, J1, 2, 1 Yokohama National University2 National Institute of Advanced Industrial Science and Technology
ABSTRACT- Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like PCBs were measured in seawater in the Tokyo Bay and in 6 major rivers that flow into the Tokyo Bay. About 100-200 L of river and seawater was collected, then immediately filtered. Particle phase PCDD/Fs and dioxin-like PCBs were trapped in glass fibber filter (GFF) and dissolved phase PCDD/Fs and dioxin-like PCBs, which went through GFF, were trapped in polyurethane form (PUF). After filtering, GFF and PUF were extracted, cleaned and fractionated respectively. The final PCDD/Fs and dioxin-like PCBs fraction was identified and quantified by HRGC/HRMS. All mono- through octachlorinated PCDD/F and 12 dioxin-like PCB (IUPAC No. 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169 and 189) congeners were analyzed in this study. In both particulate and dissolved phase PCDD/Fs and dioxin-like PCBs, river water had several to dozens times higher concentrations compared with the Tokyo Bay seawater. It can be assumed that PCDD/Fs and dioxin-like PCBs carried by the river were diluted by seawater, resulting in low concentrations in the Tokyo Bay. In particulate phase PCDD/Fs and dioxin-like PCBs in seawater, differences in concentrations were not observed among stations except for the surface layer of the St. A, which is located in front of the mouths of large rivers. Thus, particulate phase PCDD/Fs and dioxin-like PCBs in the river deposits immediately after the river water flowed into the bay. On the other hand, concentrations in dissolved phase PCDD/Fs did not differ among sampling points. From these results, it is considered that dissolved phase PCDD/Fs and dioxin-like PCBs transported from the river is immediately diluted with seawater, revealing no marked variation in the bay.
Key words: dioxin-like PCBs, PCDD/Fs, seawater, river water