PCB monitoring with corbicula in the Lake Biwa-Yodo River System in Japan and the Pearl River Delta in China

摘要

Field surveys on the bioaccumulation characteristics of polychlorinated biphenyls (PCBs) in corbicula were conducted in the Lake Biwa-Yodo River System (LBYRS), Japan and the Pearl River Delta (PRD), China in 2007. The average total PCB concentration in water and corbicula were 1,200pg/L and 16,000pg/g-wet in the LBYRS, and 900pg/L and 3,500pg/g-wet in the PRD, respectively. Almost same isomers were remarkable in samples between the two water system, however, samples in the PRD contained much #47, #48, #155 and #184. 3 PCB isomers which have commonly at least one 2,4,5-chlorine substitution were much concentrated, and other 5 isomers which have the chlorine substitution at the position of 2,3,4,5 were less bioaccumulated exceptionally from water to corbicula. Two tendencies were clear from increases in logBCF, ascending trend before the logKow reaches the value of 6.8 and a descending trend for values above 6.8. Bioaccumulative levels in corbicula in the LBYRS were higher than those in the PRD, and it was likely that the existence form of PCBs in water would result in the difference in the bioaccumulative levels.