ABSTRACT

Emerging organophosphate flame retardants (E-OPFRs) are a new class of pollutants that have attractedincreasing attention, but their bioaccumulation patterns and trophodynamic behaviors in aquatic food webs stillneed to be validated by comparison with legacy OPFRs (L-OPFRs). In this study, we simultaneously investigatedthe bioaccumulation, trophic transfer, and dietary exposure of 8 E-OPFRs and 10 L-OPFRs in a tropical estuarinefood web from Hainan Island, China. Notably, the Σ10L-OPFRs concentration (16.1–1.18 × 105 lipid weight (lw))was significantly greater than that of Σ8E-OPFRs (nondetectable (nd) - 2.82 × 103 ng/glw) among the investigatedorganisms, and they both exhibited similar trends: fishwas found only for triphenyl phosphate (TPHP, an L-OPFR) with a trophic magnification factor(TMF) of 1.55, whereas other E- and L-OPFRs showed limited trophic transfer potential. Storage lipid was thedominant adsorption phase for most E-OPFRs and L-OPFRs on the basis of the fugacity approach. The watercontent controls the main trophic partitioning for the L-OPFRs of triethyl phosphate (TEP) and tris(2-chloroethyl)phosphate (TCEP) in the food web. Storage lipid and structure protein are equally important for 2,2-bis(chloromethyl)-propane-1,3-diyltetrakis(2-chloroethyl) biphosphate (V6, an emerging OPFR). The investigation ofmetabolites and the biotransformation rate (KM) confirmed the role of biotransformation in offsetting trophictransfer for both legacy and emerging OPFRs. Furthermore, the hazard quotients (HQs) were found to be <1 forSouth China residents for both the E- and L-OPFRs, but the health risks of these two kinds of OPFRs should begiven sustained attention.