Polychlorinated dibenzo-p-dioxins in blue mussel from marine coastal water in Japan

Polychlorinated dibenzo-p-dioxins (PCDD) were detected in all blue mussels (Mytilus edulis) collected from coastal areas in Osaka and Hokkaido during December 1984-June 1986. Average total PCDD concentrations were 250, 190, 30 and 7.6 ppt in mussels from Hokko, Misacki-Cho, Funka bay, and Rishiri Island, respectively. Corresponding PCB concentrations in these mussels were 65, 11, 1.20 and 0.56 ppb. PCDD congener ratios indicated that tetraCDD accounted for 55, 38, 30 and 32 per cent of total PCDD in Hokko, Misacki-Cho, Funka bay and Rishiri Island mussels, respectively. An increase in mussel PCDD concentrations during September 1985 was primarily due to increased tetraCDD levels, attributable to summer spraying of a chlorinated diphenyl ether herbicide containing PCDD. PCDD congener ratios in mussels differed from those in fly ash in that lower chlorinated congeners predominated in the former and higher chlorinated congeners in the latter.