原位土壤镉铜铅复合污染对天锡杜拉蚓(Drawida gisti)的毒性效应  

Toxic effects of combined pollution of cadmium,copper and lead on Drawida gisti in in situ contaminated soil

作　　者：慕晓泉 尹悦 李博 杨杨 王坤[1] MU Xiaoquan;YIN Yue;LI Bo;YANG Yang;WANG Kun(College of Resources and Environmental Sciences/State Key Laboratory of North China Crop Improvement and Regulation,Hebei Agricultural University,Baoding 071000,China)

机构地区：[1]河北农业大学资源与环境科学学院/华北作物改良与调控国家重点实验室,河北保定071000

出　　处：《河北农业大学学报》2023年第6期25-33,共9页Journal of Hebei Agricultural University

基　　金：河北省自然科学基金(C2019204307);河北省教育厅高等学校重点项目(ZD2020173);中央引导地方科技发展项目(226Z4201G)。

摘　　要：为探究河北省保定周边地区重金属(Cd、Cu与Pb)污染土壤对蚯蚓的毒性效应,采用室内培养方法,分别在清洁土(S0)和2种原位重金属[Cd-Cu(S1)和Cd-Cu-Pb(S2)]污染土壤下,研究野生蚓—天锡杜拉蚓(Drawida gisti)暴露7、14和28 d后生物量变化、重金属富集及其生化响应特征。结果表明:1)随暴露时间增加,S1与S2污染土壤下天锡杜拉蚓的生物量均显著下降(P<0.05);2)S1与S2处理下蚯蚓重金属富集系数(BAF)均表现为Cd>Pb>Cu,且S1处理下BAF均大于S2下结果,这与污染土中重金属有效性有关;3)采用IBRv2指数分析蚯蚓体内生化指标(TP、GPx、GSH、MDA和AChE)的变化趋势。前期暴露7 d时S1与S2处理下蚯蚓体内各项生化指标响应剧烈,表现为机体氧化胁迫、脂质损伤、神经抑制和蛋白消耗,GSH与GPx参与解毒过程等现象;14 d时蚯蚓体内各项指标趋于平缓(MDA降低,AChE与GPx活性抑制);28 d时S1与S2处理下蚯蚓响应呈相似趋势(GPx与AChE激活)。根据IBRv2综合指数,S1与S2处理下天锡杜拉蚓IBRv2指数呈先升后降趋势,其中14 d时机体应激反应显著;随着暴露时间的增加,Cd-Cu复合污染土壤对天锡杜拉蚓在生化水平上的毒性效应表现更强。研究结果可为土壤重金属Cd、Cu和Pb复合污染对蚯蚓的生态风险评价提供理论依据。In this study,we investigated the toxic effects of heavy metal(Cd,Cu and Pb)-contaminated soil on field earthworm species Drawida gisti.The soil was sampled in vicinity of Baoding City of Hebei Province in North China.Herein,a microcosm study was performed to investigate the changes in biomass,bioaccumulations of Cd,Cu and Pb,and the responses of biomarkers including total protein(TP),malondialdehyde(MDA),glutathione(GSH),glutathione peroxidase(GPx)and acetylcholinesterase(AChE)in D.gisti after 7,14,and 28 days of exposure to the Cd-Cu and Cd-Cu-Pb contaminated soils and the uncontaminated soils.Our results showed that the biomass of D.gisti was significantly decreased in S1 and S2 treatments with prolonged exposure(P<0.05).The values of bioaccumulation factors(BAFs)of earthworm D.gisti were generally in order of Cd>Pb>Cu.The values of BAF_(Cd),BAF_(Cu)and BAF_(Pb)of earthworm under S1 treatment were higher than that under S2 exposure(BAF_(Cd)>1),which was attributed to the changes of the bioavailable fractions of metals in soils.We used IBRv2 index to reveal the changes of physiological biomarkers(TP,MDA,GSH,GPx and AChE)in the earthworms.The results suggested that the biomarkers in earthworm highly responded to oxidative stress at early exposure stage in both S1 and S2 treatments,including lipid damage,nerve inhibition,protein consumption,and detoxification process involving GSH and GPx.After 14 days of exposure,all indexes in the earthworm tended to be steady with decreased MDA and inhibited AChE and GPx activities.After 28 days,the responses of earthworm were similar in S1 and S2 treatment with activation of GPx and AChE.Accordingly,the IBRv2 index of S1 and S2 treatment increased and then decreased along the exposure duration illustrating a significant response at day 14.With prolonged exposure,Cd-Cu composite contaminated soil displayed a stronger toxic effect on the physical levels of the Drawida gisti.Our results provided theoretical basis for the ecological risk assessment of earthworm D.gisti with the e

关 键 词：重金属 天锡杜拉蚓 富集 氧化应激 综合生物标志物指数(IBRv2) 

分 类 号：S155.4[农业科学—土壤学]