The distribution and accumulation of phosphate flame retardants (PFRs) in water environment

Phosphate flame retardants (PFRs) were measured in surface water (n=11), suspended particle matter (SPM, n=11), sediment (n=11), and fish samples (n=26) from the Pearl River Delta located in South China. Triethyl phosphate (TEP), tri(2-chloroethyl) phosphate (TCEP), tris(chloroisopropyl) phosphate (TCIPP), tri-n-butyl phosphate (TNBP), triphenyl phosphate (TPHP), and tricresyl phosphate (TMPP) were detected in more than half of surface water, SPM, and sediment samples. The median ΣPFR levels were 837ng/L, 54.6ng/g dry weight (dw), and 37.1ng/g dw in surface water, SPM, and sediment samples, respectively. No significant correlations were found between the concentrations of most PFRs and organic carbon contents in SPM and sediment (p>0.05). In surface water samples, tris(2-butoxyethyl) phosphate (TBOEP, 27% of ΣPFRs) and TEP (23% of ΣPFRs) were the predominant chemicals, while TNBP (38% of ΣPFRs) and TCEP (32% of ΣPFRs) dominated in ΣPFRs in SPM samples, and TCEP (48% of ΣPFRs) and TCIPP (25% of ΣPFRs) dominated in ΣPFRs in sediment samples. The proportions of phenyl-PFRs and chlorinated-PFRs in ΣPFRs increased from surface water to SPM and sediment. The distribution ratios of PFRs between water and organic carbon in SPM (or observed K_OC) were generally 2-3 orders of magnitude higher than the predicted K_OC. TNBP (nd-2.42ng/g wet weight (ww)), TCEP (nd-4.96ng/g ww), and TCIPP (nd-2.42ng/g ww) were detected in 27%, 35%, and 23% of all fish samples, respectively. The log bioaccumulation factors (BAFs) ranged 2.56-2.78, 2.15-3.11, and 2.61-3.10 for TNBP, TCEP, and TCIPP, respectively. The biota-sediment accumulation factors (BSAFs) of TNBP, TCEP, and TCIPP were generally lower than 1 except for the BSAF of TCIPP in common carp. The results indicate the species-specific bioaccumulation of PFRs in fish species.