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

Abstract

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 KOC) were generally 2–3 orders of magnitude higher than the predicted KOC. 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.