Occurrence, Spatiotemporal Variation, Source, and Risk of Organophosphate Triesters and Diesters in Soil of E-waste Dismantling Parks.

Although organophosphate esters (OPEs) have been widely investigated, the environmental behavior and source characteristics of both OPEs and diesters (di-OPEs) across e-waste dismantling parks remain insufficiently understood. We quantified 20 OPEs and 8 di-OPEs in 151 soil samples from two e-waste dismantling parks (historical vs. active) from 2020 to 2023. OPE and di-OPE concentrations ranged 5.92-5671 ng/g dw and 0.0923-840 ng/g dw, with TCIPP, TCEP, and BEHP as dominant compounds. Higher OPE and di-OPE concentrations inside parks than in surrounding soils suggest e-waste dismantling as a significant source, with a more pronounced difference in Park B indicating that systematic control measures may limit the dispersion of OPEs. Elevated proportions of TDCPP and emerging aryl-OPEs in Park B suggest that soil profiles in e-waste areas reflect shifts in OPE applications within electronic materials. Significant interannual variation of OPEs in Park A was driven by sporadic localized inputs, whereas stable levels in Park B imply a dynamic equilibrium between ongoing release and environmental removal. PCA indicated e-waste dismantling, foam-related or domestic sources, commercial isopropylated triarylphosphate mixtures, and hydraulic oil from equipment as potential OPE sources. Correlation analysis and parent-metabolite ratios indicate that di-OPEs in active Park B originate primarily from parent degradation, while this relationship was weaker in the legacy Park A. Ecological risks were predominantly medium to high, with TMPP as the primary contributor; human health risks from soil OPEs and di-OPEs were within acceptable limits. This study has important implications for risk assessment and management of OPEs in e-waste-affected areas.