Unbalanced Pollution and Ecological Risk of Organophosphate Esters in Chinese Surface Water and Land Use Under Multiple Driving Factors

The large-scale use of organophosphate esters (OPEs) as flame retardants and plasticizers, has led to their prevalence in the surrounding environment, with unknown broader impacts. This study describes the distribution of OPEs in water and soil environments, explores the correlation between their distribution and socioeconomic or climatic characteristics, and assesses the ecological risk of OPEs to aquatic and terrestrial organisms. Our findings showed that socioeconomic characteristics, including the model of industrial development, population density, urbanization, and treatment rate of domestic sewage, play a significant role in driving the distribution of OPEs in surface water and land use. The excessive use of industrial and domestic water directly and indirectly increases the concentrations of OPEs in surface water, and an increase in precipitation can wash out OPEs in the surface soil and allowing them to seep into the groundwater aquifer. OPEs were most prevalent in surface water and land use, but more notable concentrations were also found in farming (∑OPEs: 1.19 ng g−1–1224.61 ng g−1) and construction lands (∑OPEs: 0.8 ng g−1–11,557.83 ng g−1). Based on the risk quotient and risk prioritizing (i.e., expected risk) methods, the ecological risks of OPEs to terrestrial organisms are more sensitive than those on aquatic organisms, particularly for tricresyl phosphate, tris(phenyl) phosphate, tris(2-ethylhexyl) phosphate, tris(2,3-dibromopropyl) phosphate, and 2-ethylhexyl diphenyl phosphate. However, the lack of clear dose–response relationships and toxicological data for most OPEs severely limits their risk assessment. Future research should focus on assessing the impacts of these OPEs on aquatic and terrestrial biodiversity, as well as on strengthening risk management and control.