New Perspective to Understand and Prioritize the Ecological Impacts of Organophosphate Esters and Transformation Products in Urban Stormwater and Sewage Effluents

Due to their prevalence in urban contaminated water,the drivingfactors of organophosphate esters (OPEs) need to be well examined,and their related ecological impacts should include that of theirtransformation products (TPs). Additionally, a robust framework needsto be developed to integrate multiple variables related to ecologicalimpacts for improving the ecological health assessment. Therefore,OPEs and TPs in urban stormwater and wastewater in Hong Kong wereanalyzed to fill these gaps. The results revealed that the total concentrationsof OPEs in stormwater were positively correlated with the area oftransportation land. Individual TP concentrations and the mass ratiosof individual TPs/OPEs were somewhat higher in sewage effluents thanthat in stormwater. OPEs generally showed relatively higher risk quotientsthan TPs; however, the total risk quotients increased by approximately38% when TPs were factored in. Moreover, the molecular docking resultssuggested that the investigated TPs might cause similar endocrinedisruption in marine organisms as their parent OPEs. This study employedthe Toxicological-Priority-Index scheme to successfully integratethe ecological risks and endocrine-disrupting effects to refine theecological health assessment of the exposure to OPEs and their TPs,which can better inform the authority on the prioritization for regulatingthese contaminants of emerging concern in urban built environments. A novel framework integrating toxicity,exposure, endocrinepathways, and chemical properties has identified BEHP and DPHP asemerging contaminant candidates in urban contaminated water.

Automated summary

This study analyzed the concentrations of organophosphate esters (OPEs) and their transformation products (TPs) in urban stormwater and wastewater in Hong Kong. The results showed that OPEs and TPs have ecological impacts, and TPs may cause endocrine disruption in marine organisms. A novel framework integrating various factors has been proposed to assess and regulate the risks of these emerging contaminants in urban environments.