Exposure risk assessment of representative phthalate acid esters and associated plastic debris under the agricultural land use in typical Chinese regions.

Phthalate acid esters (PAEs) are frequently detected in the global environment and can cause potential health hazards. In this study, quantitative exposure risk assessment was undertaken to derive soil generic assessment criteria (GAC) for six representative PAEs under the agricultural land use in the evaluated Chinese regions, which coupled multi-media transport and human exposure models based on multiple exposure pathways including vegetables consumption, dermal absorption, ingestion of soil and dust, and the exposure from non-soil sources. It is identified that the PAEs in agricultural soil are dominated by DEHP and DnBP representing 72-96% of the total PAEs. The GAC for BBP and DEHP, calculated on the basis of region-specific exposure parameters and soil properties in various locations, are stringent, signifying greater potential health risks from exposure to them, warranting more rigorous contamination management. The proposed soil GAC for plastic debris are 100, 107, 73 and 88 mg kg-1 for Heilongjiang Province, Beijing City, Jiangsu and Guangdong Provinces respectively. Additionally, the potential risks of 1.68 × 10-6 and 7 × 10-6 are identified for BBP and DEHP in Guangdong Province as indicated by the exceedance of target risk level of 1 × 10-6, with the consumption of vegetables being the dominant contributor to the total estimated PAEs exposure. Overall, this methodology based on the coupled contaminant transport and exposure models incorporating region-specific data provides a technical framework to derive science-based soil GAC for representative PAEs for maintaining and assessing soil quality and food safety under the agricultural land use.