Occurrence, Bioaccumulation, and Trophic Transfer of Oligomeric Organophosphorus Flame Retardants in an Aquatic Environment

Oligomeric organophosphorus flame retardants (oOPFRs) are extensively used as substitutes for decabromodiphenyl ether. However, little is currently known about their occurrence in aquatic environments, their bioaccumulation, or their trophic transfer. In this study, concentrations of two o-OPFRs, bisphenol A bis(diphenyl phosphate) (BPA-BDPP) and 1,3-phenylene bis-(diphenyl phosphate) (PBDPP), were measured in water, sediment and food web organisms (plankton, invertebrates, and fishes) from Taihu Lake, China. BPA-BDPP was detected for the first time in surface water (<0.002-0.21 ng/L) and was frequently detected in sediment with concentrations (0.005-89 ng/g dry weight (dw)) comparable to the sum of traditional monomeric OPFRs (Em-OPFRs, 6.0 to 1.0 X 10(2) ng/g dw). BPA-BDPP was also detected in all biota species (0.012-0.52 ng/g wet weight (ww)). PBDPP was detected only in sediment (<0.004-1.2 ng/g dw) and aquatic organisms (<0.002-0.22 ng/g ww), at lower levels than BPA-BDPP. BPA-BDPP showed higher bioaccumulation factors (4.0 X 10(3) L water/g of lipid for plankton, 1.3 X 10(2) to 2.1 X 10(3) L water/g of lipid for fish species) than m-OPFRs (1.0 to 1.6 X 10(3) L water/g of lipid for plankton, 0.041 to 6.5 x 10(2) L water/g of lipid for fish species). The biota-sediment accumulation factors of BPA-BDPP and PBDPP were 0.54-1.7 g of TOC/g of lipid and 14.3-26.4 g of TOC/g of lipid, respectively. Concentrations of BPA-BDPP (ng/g lipid weight) decreased with trophic levels of the aquatic biota but without statistical significance (p = 0.07), which was likely induced by its rapid metabolism in fish. The results in this study will be important for future ecological risk assessments of emerging o-OPFRs.