College of Resources and Environment, Key Laboratory of Agricultural Environment, Shandong Agricultural University, Tai'an, 271000, China.
College of Resources and Environment, Key Laboratory of Agricultural Environment, Shandong Agricultural University, Tai'an, 271000, China; College of Natural Resources and Environment, Northwest A＆; F University, Yangling, 712000, PR China.
Environ Pollut. 2023 Apr 1;322:121204. doi: 10.1016/j.envpol.2023.121204. Epub 2023 Feb 6.
As one of the most critical soil faunas in agroecosystems, earthworms are significant in preserving soil ecological health. Di (2-ethylhexyl) phthalate (DEHP) is a major plasticizer and widely used in plastic products like agricultural films. However, it has become ubiquitous contaminant in agricultural soil and poses a potential threat to soil health. Although the awareness of the impacts of DEHP on soil ecology is increasing, its adverse effects on soil invertebrates, especially earthworms, are still not well developed. In this study, the ecotoxicological effects and underlying mechanisms of environmentally relevant doses DEHP on earthworms of different ecological niches were investigated at the individual, cytological, and biochemical levels, respectively. Results showed that the acute toxicity of DEHP to M. guillelmi was higher than E. foetida. DEHP induced reactive oxygen species (ROS) levels and further caused oxidative damage (including cellular DNA and lipid peroxidation damage) in both species, speculating that they may exhibit similar oxidative stress mechanisms. Furthermore, two earthworms presented the alleviated toxicity when re-cultured in uncontaminated circumstances, yet, the accumulated ROS in bodies could not be completely scavenged. Risk assessment indicated that the detrimental impacts of DEHP were more significant in the M. guillelmi than in E. foetida in whole experiments prides, and the biomarkers additionally showed a species-specific trend. Besides, molecular docking revealed that DEHP could bind to the active center of superoxide dismutase/catalase (SOD/CAT) by hydrogen bonding or hydrophobic interactions. Overall, this study will provide a novel insight for accurate contaminant risk assessment, and also highlight that the comprehensive biological effects of different species should be emphasized in soil ecological health diagnostics and environmental toxicology assays, as otherwise it may lead to underestimation or misestimation of the soil health risk of contaminants.
作为农业生态系统中最重要的土壤动物之一，蚯蚓在保护土壤生态健康方面具有重要意义。邻苯二甲酸二（2-乙基己基）酯（DEHP）是一种主要的增塑剂，广泛用于农业薄膜等塑料制品中。然而，它已成为农业土壤中无处不在的污染物，对土壤健康构成潜在威胁。尽管人们越来越意识到 DEHP 对土壤生态的影响，但它对土壤无脊椎动物，特别是蚯蚓的不良影响仍未得到充分研究。在这项研究中，分别在个体、细胞学和生化水平上研究了环境相关剂量 DEHP 对不同生态位蚯蚓的生态毒理学效应及其潜在机制。结果表明，DEHP 对 M. guillelmi 的急性毒性高于 E. foetida。DEHP 诱导了两种蚯蚓的活性氧（ROS）水平升高，并进一步导致了氧化损伤（包括细胞 DNA 和脂质过氧化损伤），推测它们可能表现出相似的氧化应激机制。此外，两种蚯蚓在重新培养到无污染环境中时表现出毒性缓解，但体内积累的 ROS 无法完全清除。风险评估表明，在整个实验过程中，DEHP 对 M. guillelmi 的有害影响比 E. foetida 更显著，生物标志物也表现出种特异性趋势。此外，分子对接表明，DEHP 可以通过氢键或疏水相互作用与超氧化物歧化酶/过氧化氢酶（SOD/CAT）的活性中心结合。总的来说，这项研究将为准确的污染物风险评估提供新的见解，并强调在土壤生态健康诊断和环境毒理学检测中应强调不同物种的综合生物效应，否则可能会导致对污染物土壤健康风险的低估或误估。
