Contamination by butyltin compounds in sediments, cultured fishes (Seriola quinqueradiata and Pagrus major) and pearl oysters (Pinctada martensii) collected from Uwa Sea, Japan [Japanese]

摘要

Butyltin compounds (MBT, DBT, TBT) were determined in surface sediments, sediment cores, cultured fishes and pearl oysters collected from Uwa Sea, Japan. TBT concentrations in surface sediments ranged from 2.8 to 930 ng/g dry wt, which were comparable to those in urban regions such as Tokyo Bay, Osaka Bay and Dokai Bay. SigmaBTs (MBT + DBT + TBT) concentrations in surface sediments from fish culture areas were significantly higher than those from pearl oyster areas. In case of sediment cores, BTs concentration was the highest in the surface layer and decreased with core depth. SigmaBTs concentrations in pearl oysters were lower than those in other species of bivalves from various coastal waters around the world, whereas SigmaBTs concentrations in cultured fish from Uwa Sea were comparable to those reported in Osaka Bay. Higher proportions of TBT in SigmaBTs residues were found in fish and pearl oysters than in sediments. Although TBT concentrations found in cultured fishes were less than the tolerable level estimated from ADI suggested by the Ministry of Health and Welfare, efforts to reduce the residue levels are needed for the conservation of ecosystems.