Given the wide use of plastic and pesticides in agriculture, microplastics (MP) and the herbicide 2,4 dichloro-phenoxy-acetic acid (2-4-D) can be present simultaneously in soil. Nevertheless, little is known about their combined toxicity. In this study, Eisenia andrei was exposed to environmental MP (100 µg kg^-1 soil) and 2,4-D (7 mg kg^-1 soil) for 7 and 14 days. Bioaccumulation, genotoxicity, oxidative stress and gene expression level were assessed. Results revealed that MP increased 2,4-D bioaccumulation in earthworms. Simultaneous exposure to both these pollutants caused a significant reduction in lysosomal membrane stability (LMS) and an increase in micronuclei (MNi) frequency. Biochemical analysis revealed oxidative alterations in earthworms exposed to all treatments; being very pronounced in earthworms exposed to the mixture in terms of increase in glutathione-S-Transferase (GST), catalase (CAT) and malondialdehydes accumulation (MDA). Furthermore, an up-regulation in cat and gst expression level was recorded in worms exposed to single or mixture treatment, except MP in case of gst. Our data highlight the toxicity of the combined exposure to MP and 2,4-D and afford new insights into the potential ecological risks posed by MP in terrestrial ecosystems.

鉴于塑料和杀虫剂在农业中的广泛使用，微塑料 (MP) 和除草剂 2,4 二氯苯氧基乙酸 (2-4-D) 可以同时存在于土壤中。然而，人们对它们的综合毒性知之甚少。在这项研究中，Eisenia andrei暴露于环境 MP（100 µg kg ^-1土壤）和 2,4-D（7 mg kg ^-1土壤）7 天和 14 天。评估了生物积累、基因毒性、氧化应激和基因表达水平。结果显示，MP 增加了蚯蚓体内的 2,4-D 生物积累。同时暴露于这两种污染物会导致溶酶体膜稳定性 (LMS) 显着降低和微核 (MNi) 频率增加。生化分析揭示了蚯蚓在所有处理中的氧化变化；在谷胱甘肽-S-转移酶（GST）、过氧化氢酶（CAT）和丙二醛积累（MDA）的增加方面，在暴露于混合物的蚯蚓中非常明显。此外，在暴露于单一或混合处理的蠕虫中记录到 cat 和 gst 表达水平的上调，在 gst 的情况下 MP 除外。我们的数据突出了 MP 和 2 联合暴露的毒性，