纳米零价铁对赤子爱胜蚓的毒性效应研究  

Study on the Toxic Effects of Nano Zero Valent Iron on Eisenia fetida

作　　者：罗庆睿 赵奕乔 蔡粤 段昌群[1,2,3] 刘嫦娥 LUO Qingrui;ZHAO Yiqiao;CAI Yue;DUAN Changqun;LIU Chang'e(School of Ecology and Environment,Yunnan University and Yunnan Provincial Key Laboratory of Highland Mountain Ecology and Degraded Environment Restoration,Kunming 650500,China;Yunnan Field Scientific Observatory for Ecological Function Restoration in Ecologically Sensitive Areas in Central Yunnan Province,International Joint Research Center for Ecological Restoration and Watershed Management of Plateau Lakes in Yunnan Province,Yunnan Think Tank for Ecological Civilization Construction,Kunming 650091,China;Southwest Joint Graduate School&International Institute for River and Ecological Security,Kunming 650500,China)

机构地区：[1]云南大学生态与环境学院暨云南省高原山地生态与退化环境修复重点实验室,昆明650500 [2]滇中生态敏感区生态功能修复云南省野外科学观测研究站,云南省高原湖泊生态修复及流域管理国际联合研究中心,云南省生态文明建设智库,昆明650091 [3]西南联合研究生院&国际河流与生态安全研究所,昆明650500

出　　处：《生态毒理学报》2025年第1期397-408,共12页Asian Journal of Ecotoxicology

基　　金：国家自然科学基金资助项目(32260315);云南省基础研究计划重点项目(202201AS070016,202203AC100002)。

摘　　要：纳米零价铁(nanoscale zero-valent iron,nZVI)在处理污染物方面显示出巨大潜力而得到了广泛研究。目前只有少数研究调查了nZVI的潜在生态毒性。本研究通过室内控制实验,设置对照(0 g·kg^(-1))、低(2.5 g·kg^(-1))、中(5.0 g·kg^(-1))、高(10.0 g·kg^(-1))4个nZVI浓度梯度对赤子爱胜蚓(Eisenia fetida)进行为期28 d的暴露实验,运用整合生物标志物响应(integrated biomarker responses,IBR)指数评价28 d内蚯蚓生物标志物变化,结合Eisenia fetida体内铁的生物富集量,阐明nZVI对蚯蚓的生理生化毒性效应。研究表明:nZVI处理浓度及暴露时间对蚯蚓存活率、生物量损失及其8个生理生化指标具有不同程度的显著影响。随着暴露时间的延长,Eisenia fetida的存活率、生物量及各项酶活性逐渐降低,同时其存活率及生物量也随着nZVI浓度的增加而降低。总的来说,nZVI胁迫会使Eisenia fetida体内活性氧(reactive oxygen species,ROS)过度积累,使其产生氧化应激并造成DNA及细胞损伤,同时其体内的乙酰胆碱酯酶(acetylcholinesterase,AchE)及抗氧化酶系统会迅速做出反应抵御外来胁迫;Eisenia fetida分泌大量金属硫蛋白(metallothionein,MT)与铁形成稳定的复合物来降低其细胞毒性。通过IBR指数的计算发现:暴露初期Eisenia fetida受到nZVI带来的氧化胁迫导致ROS含量大量积累,故在暴露第7天时ROS的IBR指数偏差最大;暴露第14天时抗氧化防御系统正作出反应抵御外来胁迫,此时过氧化氢酶(catalase,CAT)的IBR指数偏差最大;在暴露第28天时,8-羟基脱氧鸟苷(8-hydroxy-2’-deoxyguanosine,8-OHdG)的IBR指数偏差最大,此时蚯蚓受到的脱氧核糖核酸(deoxyribonucleic acid,DNA)氧化损伤最为严重。本研究为nZVI的环境风险评估提供参考和技术支持。Nano-zero-valent iron(nZVI)has been extensively studied due to its promising potential in pollutant remediation.However,limited research has focused on the potential ecotoxicity of nZVI.In this study,a controlled indoor experiment was conducted using four nZVI concentration gradients:control(0 g·kg^(-1)),low(2.5 g·kg^(-1)),medium(5.0 g·kg^(-1)),and high(10.0 g·kg^(-1)),on Eisenia fetida over a period of 28 days.Changes in biomarkers of earthworms were evaluated using the integrated biomarker responses(IBR)over this 28-day period to elucidate the effects of nZVI on Eisenia fetida.The study revealed that both the nZVI treatment concentration and exposure duration significantly impacted the survival rate,biomass loss,and eight physiological and biochemical indicators of earthworms.As exposure time increased,the survival rate,biomass,and enzyme activities of Eisenia fetida gradually declined.Similarly,both the survival rate and biomass decreased with rising nZVI concentrations.In summary,nZVI stress induced excessive accumulation of reactive oxygen species(ROS)in Eisenia fetida,leading to oxidative stress,DNA damage,and cellular injury.Simultaneously,the earthworms’acetylcholinesterase and antioxidant enzyme system responded rapidly to defend against external stress.Eisenia fetida secreted substantial amounts of metallothionein to form stable complexes with iron,thereby reducing its cytotoxicity.Calculations of the IBR indices revealed that the oxidative stress induced by early exposure to nZVI led to a significant accumulation of ROS in Eisenia fetida,resulting in the largest deviation in the ROS IBR index on the 7th day of exposure.By the 14th day,the antioxidant defense system was actively responding to the stress,with the largest deviation observed in catalase.By the 14th day of exposure,the antioxidant defense system had become actively engaged in counteracting the stress,with catalase exhibiting the most pronounced deviation in its activity.On the 28th day,the largest deviation in the IBR index for 8-hydr

关 键 词：纳米零价铁 赤子爱胜蚓 氧化损伤 生物标志物 生物富集 综合毒性指数 

分 类 号：X171.5[环境科学与工程—环境科学]