Insights into organophosphate esters (OPEs) in aquatic ecosystems: Occurrence, environmental behavior, and ecological risk

Given the widespread use as flame retardants, plasticizers, and organophosphate esters (OPEs) received increasing scientific interests on their occurrence and ecotoxicological research progress. This review comprehensively conducted bibliometric analysis and surveyed the OPEs occurrence in aquatic ecosystem (water, sediment, and aquatic organisms) and human-related (drinking water and sewage) over the past decade to unraveling knowledge gaps. The OPEs concentrations in water, sediment were at the range of not detected (n.d.) or several to hundreds ng/g or ng/L and exhibited landuses-specific characteristics. The electronic waste (e-waste) processing activities and sewage discharge were identified as point sources of OPEs in aquatic environment. Emission source intensity, water chemistry, and content of organic carbon were important for the partition and transfer processes of OPEs in the water, as well as hydrophobicity of OPEs dominating the absorption on the organic matter. Degradation, especially photodegradation and reductive degradation, has application potential in improving removal efficiencies of chlorinated-OPEs (Cl-OPEs) being reluctant to degrade. Generally, most surveyed OPEs have negligible ecological and health risks, whereas those OPEs with moderate threats or chronic effects on aquatic ecosystem should gain more attention. This review elucidates the status of OPEs pollution in water and highlights the need for more transport and degradation studies on traditional and emerging OPEs and metabolites to further identify potential threats on aquatic ecosystem.