MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China.
Institute of Surface-Earth System Science, College of Earth System Science, Tianjin University, Tianjin 300072, PR China.
Environ Pollut. 2023 Apr 15;323:121275. doi: 10.1016/j.envpol.2023.121275. Epub 2023 Feb 11.
The ecological risk of heavy metal-contaminated soil is usually evaluated by its oxidative stress on terrestrial animals, which are vulnerable to the impact of individual differences of animals and environmental conditions. Oxidative potential (OP) is the potential of particles to induce the formation of reactive oxygen species (ROS). In this study, OP of the in situ contaminated soils collected from an industrial site (i.e., 64.5-7783 mg/kg of Cu, 54.9-397 mg/kg of Pb, 278-2085 mg/kg of Zn and 0.615-121 mg/kg of Cd) were measured as 38.0-60.1 pmol/min/mg, and the water extractable Cu, Pb, Zn, and Cd in soils have been proved to contribute 89%-98% to OP. Oxidative stress in earthworms (Eisenia fetida) caused by the industrial contaminated soils can be reflected by the biomarkers such as 8-hydroxy-2'-deoxyguanosine, metallothionein, and antioxidant enzymes, and a negative correlation presents between the comprehensive biomarker response index and the OP of soils (r = -0.979, p < 0.01). This is the first time to propose a dose-response relationship between OP and oxidative stress. Metabolomic analysis also verified that the regulation of four ROS-related metabolites (i.e., l-pipecolate, 1-methylhistidine, 5-methoxytryptamine, and xanthosine) in earthworms treated with contaminated soil were directly correlated with OP values. These results indicate that OP can be used as an indicator for ecological risk assessment of heavy metal-contaminated soil, which provides a fast, stable and easily testable chemical method.
受污染土壤的重金属通常会对陆地动物造成氧化应激，从而产生生态风险，而动物个体差异和环境条件会对此产生影响。氧化潜能（OP）是指颗粒诱导活性氧（ROS）形成的潜力。本研究原位采集了工业场地污染土壤（Cu：64.5-7783mg/kg、Pb：54.9-397mg/kg、Zn：278-2085mg/kg、Cd：0.615-121mg/kg），其 OP 为 38.0-60.1pmol/min/mg，且土壤中的水可提取态 Cu、Pb、Zn 和 Cd 被证明对 OP 有 89%-98%的贡献。土壤中的重金属会对赤子爱胜蚓（Eisenia fetida）产生氧化应激，进而导致其 8-羟基-2'-脱氧鸟苷、金属硫蛋白和抗氧化酶等生物标志物发生变化，土壤 OP 与综合生物标志物反应指数呈显著负相关（r=-0.979，p<0.01）。这是首次提出 OP 与氧化应激之间存在剂量-反应关系。代谢组学分析还验证了受污染土壤处理后赤子爱胜蚓中四种与 ROS 相关的代谢物（即 l-哌啶酸、1-甲基组氨酸、5-甲氧基色胺和黄嘌呤核苷）的调节与 OP 值直接相关。这些结果表明，OP 可作为重金属污染土壤生态风险评估的指标，为快速、稳定、易于检测的化学方法提供了依据。
