With the wide use of mulch film and pesticides, mulch film-derived microplastics are very likely to produce combined effects with pesticides in agricultural soil. However, little is known about their combined toxicity on terrestrial organisms. This study aimed to investigate the combined toxicity of unused or farmland residual transparent low-density polyethylene mulch film-derived microplastics (MPs and MPs-aged, respectively) (550–1000 μm) and atrazine (ATZ; 0.02 and 2.0 mg/kg) on the earthworm (Eisenia fetida). After single and combined exposure to ATZ and microplastics for 28 d, the results showed an accumulation of reactive oxygen species, a decrease in superoxide dismutase, catalase, and glutathione-S-transferase activities, an increase in the malondialdehyde and 8-hydroxydeoxyguanosine levels, and abnormal expression of annetocin, heat shock protein 70, translationally controlled tumor protein and calreticulin genes. Integrated biological response (IBR) values calculated at the biochemical level indicated that the combined exposure to ATZ and microplastics, particularly to high concentrations of ATZ, induced greater oxidative stress in E. fetida compared with that of exposure to ATZ or microplastics alone. In addition, the IBR values calculated at the gene level did not show regular changes after combined exposure to ATZ and microplastics compared with those of a single exposure. The oxidative stress and abnormal expression of genes in E. fetida induced by MPs-aged were higher than those induced by MPs; a similar trend was observed for oxidative stress induced by MPs/MPs-aged + ATZ2.0, whereas an opposite trend was observed for the abnormal expression of genes in E. fetida induced by MPs/MPs-aged + ATZ0.02/ATZ2.0. Our results suggest that mulch film-derived microplastics have the potential to enhance the toxicity of ATZ within the soil environment.

随着地膜和农药的广泛使用，地膜衍生的微塑料很可能在农业土壤中与农药产生联合作用。但是，关于它们对陆地生物的综合毒性知之甚少。这项研究旨在调查未使用的或农田残留的透明低密度聚乙烯覆盖膜衍生的微塑料（分别为MPs和MPs老化的）（分别为550-1000μm）和A去津（ATZ； 0.02和2.0 mg / kg）的综合毒性。在worm上（Eisenia fetida）。单独和联合暴露于ATZ和微塑料28 d后，结果显示活性氧积累，超氧化物歧化酶，过氧化氢酶和谷胱甘肽S-转移酶活性降低，丙二醛和8-羟基脱氧鸟苷水平升高，以及anantocin，热休克蛋白70，翻译控制的肿瘤蛋白和钙网蛋白基因的异常表达。在生化水平上计算的综合生物响应（IBR）值表明，暴露于ATZ和微塑料，尤其是高浓度的ATZ，共同导致了F. fetida的氧化应激与仅接触ATZ或微塑料相比。此外，与单次接触相比，在基因水平上计算出的IBR值在ATZ和微塑料联合接触后没有显示出规律的变化。MPs诱导的大肠埃希菌的氧化应激和基因异常表达均高于MPs诱导的。对于MPs / MPs老化+ ATZ2.0诱导的氧化应激，观察到类似的趋势，而MPs / MPs老化+ ATZ0.02 / ATZ2诱导的在大肠杆菌中基因表达异常的趋势相反。 0。我们的结果表明，覆盖膜衍生的微塑料具有增强ATZ在土壤环境中的毒性的潜力。