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

Abstract

Alternative brominated flame-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 decabromodiphenyl 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 filter-feeding bivalve (Corbicula fluminea) and grazing gastropod (Elimia proxima), 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 363,000 and 151,000 ng g(-1) lw, and those of polybrominated diphenyl ethers (∑PBDEs) were 64,900 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 debromination 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.

Bioaccumulation kinetics of polybrominated diphenyl ethers and decabromodiphenyl ethane from field‐collected sediment in the oligochaete, Lumbriculus variegatus

“…After addition of the surrogate 13 C-CB-141 and several pieces of activated copper sheets, 5 g of freeze-dried sediment was extracted with a mixture of acetone and hexane (1:1, v:v) for 48 h in a Soxhlet apparatus. The extract was concentrated to approximately 1 mL using a Zymark TurboVap, solvent-exchanged to hexane, and then concentrated to approximately 2 mL.…”

“…Target BFRs were eluted from the column with 10 mL of hexane and 30 mL of 50% dichloromethane in hexane. The eluent was concentrated to 100 mL, and the internal standard 13 C-CB-208 was added before GC/MS analysis.…”

“…Qualification of the analytes was based on simultaneous detection of the target and qualifier ions within 1% of retention time windows in the selective ion monitoring mode. Ion fragments of a mass-to-charge ration (m/z) of 487 and m/z 489 were used as the target and qualifier ions for BDE-209; m/z 79 and m/z 81 for DBDPE and less brominated PBDE congeners; m/z 372 and m/z 374 for 13 C-CB-141; and m/z 474 and m/z 476 for 13 C-CB-208, respectively. Quantification was based on internal calibration, with 13 C-CB-208 being the internal standard.…”

“…The structures and physicochemical properties of target BFRs are given in Supplemental Data, Figure S1 and Table S1. Two isotopelabeled polychlorinated biphenyls (PCBs), 13 C-CB-141 and 13 C-CB-208, were purchased from Cambridge Isotope Laboratories and used as the surrogate and the internal standard, respectively, for analyzing BFRs by gas chromatography/mass spectrometry (GC/MS).…”

PBDE flame retardants

“…30,31 Studies show that BDE-209 is bioaccumulating in a large number and variety of biota residing all over the world, including, for example, in birds and bird eggs, 32,33 terrestrial and aquatic mammals, [34][35][36] and plankton, fish and shellfish. 20,37 Human body burdens of BDE-209 also appear to be rising including among E-waste workers and people residing near PBDE production facilities 38,39 as well as among the general population, particularly young children in the US. 18,40 People residing in some regions of China with heavy E-waste recycling operations report some of the highest PBDE body burdens in the world, with BDE-209 concentrations in serum at greater than 3000 ng/g lipid.…”