In Situ Accumulation of HBCD, PBDEs, and Several Alternative Flame-Retardants in the Bivalve (Corbicula fluminea) and Gastropod (Elimia proximo)

摘要

Alternative brominated fiame-retardants (BFRs), 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB), 2-ethylhexyl 2,3,4,5-tetrabromophthalate (TBPH), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) and decabromo- diphenyl ethane (DBDPE), are now being detected in the environment. However, contaminant bioavailability is influenced by the organisms' ecology (i.e., route of uptake) and in situ environmental factors. We observed that the fiter-feeding bivalve (Corbicula fluminea) and grazing gastropod (Elimia proximo), collected downstream from a textile manufacturing outfall, exhibited TBB, TBPH, and BTBPE concentrations from 152 to 2230 ng g~(-1) lipid weight (lw). These species also contained additional BFRs. Maximum levels of total hexabromocyclododecane diastereomers (£HBCDs) in these species were 363000 and 151000 ng g~(-1) lw, and those of polybrominated diphenyl ethers (ΣPBDEs) were 64900 and 47 200 ng g~(-1) lw, respectively. These concentrations are among the highest reported to date worldwide. While BDE-209 was once thought to be nonbioavailable and resistant to degradation, it was the dominant BFR present and likely denomination products were detected. Contributions of α-and β-HBCD were higher in tissues than sediments, consistent with γ-HBCD bioisomerization. Mollusk bioaccumulation factors were similar between HBCD and PBDEs with 4 to 6 bromines, but factors for TBB, TBPH, and BTBPE were lower. Despite different feeding strategies, the bivalves and gastropods exhibited similar BFR water and sediment accumulation factors.