Distribution, traceability, and risk assessment of organophosphate flame retardants in agricultural soils along the Yangtze River Delta in China

Severe pollution threatens the ecosystem and human health in the Yangtze River Delta (YRD) in China because of the rapid development of industry in this area. This study examines the types, distribution, concentration, and origin of fourteen typical organophosphate flame retardants (OPFRs) in agricultural soils within the YRD region to offer insights for pollutant control and policy-making. The total concentration of OPFRs (ΣOPFRs) varied between 79.19 and 699.58 μg/kg dry weight (dw), averaging at 209.61 μg/kg dw. Among the OPFRs detected, tributoxyethyl phosphate (TBEP) was identified as the main congener, followed by tri-n-butyl phosphate (TnBP), tris(2-chloroisopropyl) phosphate (TCPP), and trimethyl phosphate (TMP). Source analysis, conducted through correlation coefficients and PCA, indicated that OPFRs in agricultural soils within the YRD region mainly originate from emissions related to plastic products and transportation. The health risk exposure to ΣOPFRs in agricultural soil was considered negligible for farmers, with values below 1.24 × 10 -2 and 1.76 × 10 -9 for noncarcinogenic and carcinogenic risks, respectively. However, the ecological risk of ΣOPFRs in all the samples ranged from 0.08–1.08, indicating a medium to high risk level. The results offer a comprehensive understanding of OPFR pollution in agricultural soils in the YRD region and can be useful for pollution control that mitigates ecological and health risks in this region. Graphical abstract