Organophosphate esters in the seawater of the Bohai Sea: Environmental occurrence, sources and ecological risks

Organophosphate esters (OPEs) are widely distributed in surface water systems, but limited information was available on the spatial occurrence and ecological risks of OPEs in the Bohai Sea. In this study, 89 water samples in the Bohai Sea and the five surrounding rivers were investigated for the determination of 15 OPEs. The concentration of Sigma 15OPEs ranged from 373.20 to 2931.27 ng center dot L-1 in the river water and 137.81 to 2641.30 ng center dot L-1 in the seawater, with high levels of OPEs in Liaodong Bay. Tris(2-chloroethyl) phosphate (TCEP, 10- 92 %) and triethyl phosphate (TEP, 5- 64 %) were dominant for OPEs. The correlation analysis, principal component analysis and hierarchical cluster analysis suggested the conjunction of municipal wastewater via river input and maritime shipping was the main source of OPEs in the Bohai Sea. The ecological risk assessment indicated that the individual OPEs arise low ecological risks in the Bohai Sea, while medium ecological risks of Sigma 15OPEs are in minority river samples.

Automated summary

This study investigated the spatial distribution and ecological risks of 15 organophosphate esters (OPEs) in 89 water samples from the Bohai Sea and its surrounding rivers. The results showed high levels of OPEs in Liaodong Bay. Municipal wastewater and maritime shipping were identified as the main sources of OPEs in the Bohai Sea. Ecological risk assessment indicated low ecological risks for individual OPEs, but medium ecological risks for Sigma 15OPEs in minority river samples.