Multi-biomarker evidence for ecotoxicological risk evaluation and management implications of DEHP-polyethylene...

The widespread application and residual accumulation of polyethylene (PE) agricultural films in saline soils have contributed to the co-occurrence of PE particles and plasticizers such as di-(2-ethylhexyl) phthalate (DEHP). Although the environmental presence of these agricultural film components is recognized, their combined ecological risks and the subsequent management challenges they pose remain poorly understood. The present study evaluated the comprehensive toxicity effects and ecotoxicological risk implications of DEHP alone and in co-exposure with PE on earthworms within a salinized soil environment using a multi-biomarker evaluation approach. The results revealed that both treatments induced oxidative stress, DNA damage, tissue damage, and molecular responses potentially linked to growth and reproduction. Notably, DEHP + PE co-exposure induced stronger comprehensive toxicity effects than DEHP alone in a concentration-dependent manner under the tested salinized soil conditions. To elucidate the underlying pathways and identify potential early-warning indicators for soil monitoring, transcriptomics and molecular docking were employed. Transcriptomic profiling indicated that solitary DEHP exposure primarily disrupted digestive metabolism and cellular processes. In contrast, co-exposure to DEHP and PE significantly impaired neural and vascular development pathways. Molecular docking analysis further supported these findings by illustrating the specific binding interactions of DEHP with key target proteins. Ultimately, the current study integrates multi-level biological evidence to support ecotoxicological risk evaluation of DEHP and DEHP + PE co-exposure, offering potential implications for future ecological risk assessment, soil monitoring, and sustainable management of agricultural plastic residues in saline ecosystems.