Toxicity assessment for chlorpyrifos-contaminated soil with three di erent earthworm test methods

Earthworm toxicity tests are useful tools for terrestrial risk assessment but require a hierarchy of test designs that differ in effect levels （behavior, sublethal, lethal）. In this study, the toxicity of chlorpyrifos contaminated soil on earthworms was assessed. In addition to the acute and chronic tests, an avoidance response test was applied. Earthworms were exposed to sublethal and lethal concentration of chlorpyrifos, and evaluated for acute toxicity, growth, fecundity and avoidance response after a certain exposure period. The test methods covered all important ecological relevant endpoints （acute, chronic, behavioral）. Concentration of 78.91 mg/kg, chlorpyrifos caused significant toxic effects in all test methods, but at lower test concentrations, only significant chronic toxic effects could be observed. In present study, chlorpyrifos had adverse effect on growth and fecundity in earthworm exposed to 5 mg/kg chlorpyrifos after eight weeks. The avoidance response test, however, showed significant repellent effects at concentration of 40 mg/kg chlorpyrifos. For chlorpyrifos, concentration affecting avoidance response was far greater than growth and fecundity, it seemed likely that earthworms were not able to escape from pesticide-contaminated soil into the clean soil in field and hence were exposed continuously to elevated concentrations of pesticides.     

Assessing cypermethrin-contaminated soil with three di erent earthworm test methods

A series of tests (lethal, sublethal, and behavioral) on earthworms were conducted as an eco-assessment of pesticides. In this study, the toxicity of cypermethrin-contaminating soil on adult and juvenile earthworms was assessed. Beside the acute and chronic tests, an avoidance response test was carried out. It was shown that the all-round toxicity from cypermethrin was weak on adult earthworms. Compared with adult earthworms, the toxicity of juvenile earthworms from cypermethrin especially chronic toxicity increased significantly. Growth and reproduction of earthworms appeared to be more severely a ected by cypermethrin at juvenile stage than at adult stage. Applied at 10 mg/kg, cypermethrin had obvious adverse impact on the growth of juvenile earthworms, while 20 mg/kg, cypermethrin caused significant toxic e ects in reproduction. The results also indicated that ecotoxicological risk assessment using only adult specimens may underestimate the e ects of cypermethrin on soil invertebrate populations.     

Assessing cypermethrin-contaminated soil with three different earthworm test methods

A series of tests (lethal,sublethal,and behavioral) on earthworms were conducted as an eco-assessment of pesticides.In this study,the toxicity of cypermethrin-contaminating soil on adult and juvenile earthworms was assessed.Beside the acute and chronic tests,an avoidance response test was carried out.It was shown that the all-round toxicity from cypermethrin was weak on adult earthworms.Compared with adult earthworms,the toxicity of juvenile earthworms from cypermethrin especially chronic toxicity increased...     

Individual and combined toxic effects of cypermethrin and chlorpyrifos on earthworm

Toxicities were assessed for a pyrethroid (cypermethrin) and an organophosphate insecticide (chlorpyrifos) individually and in combination. A series of tests were conducted on di erent responses (acute, chronic, behavioral) of earthworms of species Eisenia fetida andrei in the ecological risk assessment of these pesticides. The results showed that the toxicity of the mixture of cypermethrin and chlorpyrifos was significantly higher than either of these pesticides individually, especially on the earthworm’s chronic responses. At a concentration of 5 mg/kg, the mixture caused significant reductions on the growth and reproduction rates of earthworms, but did not cause any significant e ect when the individual was tested. The increase in toxicity of the pesticide mixture means that the use of toxicity data obtained exclusively from single-pesticide experiments may underestimate the ecological risk of pesticides that actually present in the field.     

Toxic effects of acetochlor and methamidophos on earthworm Eisenia fetida in phaiozem, northeast China

Introduction W ith the increase in types and am ount of pollutants releasing into soil ecosystem s, research on the joint effects of m ore than one pollutant in soil-plant, soil-anim al and soil-m icroorganism system s is increasingly concerned (Zhou and …     

锑对土壤跳虫(Folsomia candida)的毒性效应

为了解Sb（锑）对土壤无脊椎动物的毒性效应及对比不同类型土壤中Sb毒性的差异,选取死亡率、逃避率、繁殖数三组个体水平的评价指标研究了3种典型土壤（海伦黑土、祁阳红壤、北京潮土）中外源添加Sb对模式生物——跳虫（Folsomia candida）的急性毒性和慢性毒性效应.结果表明,基于实测w（Sb_总）求得的上述3种土壤中Sb影响跳虫逃避的2 d-EC₅₀（EC₅₀为半数效应浓度）分别为298、>431[高于土壤中最高w（Sb_总）]和132 mg/kg;影响跳虫死亡的7 d-LC₅₀（LC₅₀为半数致死浓度）分别为3 352、4 007、2 105 mg/kg;影响跳虫死亡的28 d-LC₅₀分别为2 271、1 865、703 mg/kg,影响跳虫繁殖的28 d-EC₅₀分别为1 799、1 323、307 mg/kg.由上述毒性阈值大小可知,跳虫逃避率的敏感性高于死亡率和繁殖数的敏感性,不同土壤中Sb对跳虫的毒性大小具有显著差异,北京潮土中Sb对跳虫的毒性与海伦黑土、祁阳红壤相比最大差别接近6倍,表明不同土壤理化性质对Sb生态毒性效应具有显著影响.但基于w（Sb_水提）求得的上述3种土壤中Sb的毒性阈值差异减小,说明水提态Sb与其毒性具有显著相关性,可以较好地解释不同土壤间Sb毒性的差异.该研究结果可为建立我国土壤中Sb的毒性预测模型及制订Sb的质量标准值提供依据.      

异丙甲草胺及其S型对映体对蚯蚓的急性毒性差异

采用OECD标准滤纸接触法、人工土壤法及自然土壤法研究了异丙甲草胺及其S型对映体对蚯蚓的急性致死作用及手性差异.结果表明,3种方法相比较,滤纸染毒法结果置信区间最大,可靠性较差.自然土壤中Rac-异丙甲草胺及S-异丙甲草胺对蚯蚓的急性毒性大于人工土壤;根据毒性分级,Rac-异丙甲草胺及其S型对映体均属于低毒级农药;3种试验方法所得的Rac-异丙甲草胺及S-异丙甲草胺对蚯蚓的LC50差别不大,表明这2种农药对蚯蚓急性毒性的手性差异较小.     

DDT和三氯杀螨醇对蚯蚓的急性和亚急性毒性影响

采用人工土培养法,通过急性和亚急性暴露实验,研究了DDT和三氯杀螨醇对蚯蚓(赤子爱胜蚓)的存活、生长和繁殖能力的影响.结果表明,DDT在急性暴露期对蚯蚓存活具有一定的毒性,其14 d的LC50为484.76 mg·kg-1;三氯杀螨醇对蚯蚓的存活基本没有影响(LC50＞4000 mg·kg-1).DDT在急性和亚急性暴露期(10～28 d)对蚯蚓的生长都具有显著的抑制作用(p＜0.05),三氯杀螨醇在急性期对蚯蚓的生长没有抑制作用(p＞0.05),在亚急性期对蚯蚓生长的影响尚不确定.DDT和三氯杀螨醇都显著抑制蚯蚓的繁殖能力(p＜0.05).     

毒死蜱暴露对蚯蚓的亚慢性神经毒性研究

蚯蚓作为土壤生态系统中重要的生物类群,在维持土壤生态系统的功能中起着重要作用.毒死蜱是我国使用量较大的有机磷农药品种之一,对以蚯蚓为代表的土壤生物具有潜在威胁.本文选择云南林地常见的蚯蚓优势种—皮质远盲蚓(Amynthas corticis)作为试验生物,从毒死蜱暴露引发的蚯蚓脑部神经递质(乙酰胆碱、多巴胺、5-羟色胺、谷氨酸)、离子通道特征酶(Ca²⁺-Mg²⁺-ATP酶、Ca²⁺-ATP酶)变化入手,对毒死蜱亚慢性神经毒性导致的蚯蚓运动、学习记忆等神经行为变化进行研究,运用综合毒性指数(IBR)评价蚯蚓生物标志物变化,开展毒死蜱暴露对蚯蚓的亚慢性神经毒性研究.结果表明：暴露期内,毒死蜱处理组中蚯蚓脑部的乙酰胆碱含量显著高于对照组(P<0.05),且随着暴露时间的增加,毒死蜱处理组中蚯蚓脑部乙酰胆碱含量持续升高,而蚯蚓脑部多巴胺、5-羟色胺、谷氨酸含量则均显著低于对照组(P均小于0.05).随着暴露时间的增加,毒死蜱对这3种神经递质含量的抑制加强,毒死蜱对蚯蚓的神经损伤导致了蚯蚓的运动迟缓和学习记忆障碍,毒死蜱暴...     

毒死蜱对斜生栅藻急、慢性毒性效应的研究

为了解有机磷农药毒死蜱污染对本土水生敏感性物种斜生栅藻的毒性效应,在实验室条件下采用静态毒性实验,研究了毒死蜱对斜生栅藻96 h急性毒性效应,并在急性试验基础上进行慢性试验,分析了不同浓度毒死蜱存在14 d后斜生栅藻叶绿素含量、可溶性蛋白以及丙二醛含量。结果表明,毒死蜱96 h EC50为8.4 mg/L;毒死蜱对斜生栅藻叶绿素a无明显毒性效应;但在前期短时间,低浓度作用下能促进可溶蛋白、MDA含量的上升,但在后期长时间胁迫作用下,总体可溶蛋白、MDA含量呈下降趋势;这说明,可溶蛋白和MDA这两个指标对毒死蜱敏感,可作为生物标志物来指示有机磷农药污染物对水生生物的影响,研究结果可为本土水生敏感性物种的保护和农药安全使用标准的制定提供理论依据。     

Effect of lead on survival, locomotion and sperm morphology of Asian earthworm, Pheretima guillelmi

To provide basic toxicity data for formulating risk characterization benchmarks, the effects of lead on survival, locomotion, and sperm morphology were investigated in the Asian earthworm Pheretima guillelmi. The LC50 of P. guillelmi for 7 and 14 d were 4285±339 mg/kg and 3207±248 mg/kg, which shows P. guillelmi can tolerate a higher concentration of lead nitrate. The average weight of the surviving earthworms decreased at concentration of 2800 mg Pb/kg soil, and the locomotor ability of earthworms exposed ...     

铬污染土壤稳定化处理对蚯蚓的毒性效应

浸出毒性测试是评价重金属污染土壤稳定化处理效果的主要方法,但该方法不能准确反映稳定化处理后土壤的生物毒性变化.本研究以多硫化钙(CPS)稳定化处理的电镀厂铬(Cr)污染土壤为对象,以赤子爱胜蚓为指示生物,研究评估土壤稳定化处理的生物毒性效应.结果表明,在Cr污染土壤中,随着CPS投加量的增加,蚯蚓的毒性效应逐渐减弱随后增强.高浓度Cr污染土壤经过CPS稳定化处理后仍然具有明显的生物毒性,CPS与土壤中Cr(VI)投加比(物质的量比,下同)为3时土壤浸出毒性虽满足浸出标准,但对蚯蚓的7 d致死效应高达100%,且暴毒期间出现肉眼可见的外部形态变化,回避率为83.3%,在暴毒第5 d时蚯蚓体内总Cr含量为20.9 mg·kg~(-1).CPS对蚯蚓具有较强的生物毒性作用,在不含Cr污染的对照组土壤中,CPS投加量与稳定化处理Cr污染土壤中稳定化药剂投加比为5相同时,蚯蚓的7 d急性毒性致死率为100%.蚯蚓的致死率和外部形态变化可快速直观地反映重金属污染土壤的生物毒性,可为土壤稳定化处理的安全性与生物毒性评估提供参考依据.     

应用标准方法测定农药对蚯蚓的毒性

本文论述使用标准化的人工土壤测定农药对蚯蚓的急性毒性的方法.实验结果证明,适用于测定农药对蚯蚓毒性的人工土壤组成为:石英砂830g/kg(干重,下同)、草炭100g/kg、膨润土50g/kg、碳酸钙10g/kg、马粪10g/kg.利用人工土壤测定久效磷、多菌灵、呋喃丹、林丹及甲基对硫磷对蚯蚓(Eiseniafoetida)的毒性.其半数致死浓度(LC_(50))分别是:0.18、4.27、12.9、70.85、74.52ppm.经用三种不同类型的自然土壤(东北黑土、华北褐土、江西红壤)及人工土壤测定呋喃丹对蚯蚓的毒性后,证实呋喃丹在人工土壤中对蚯蚓的半数致死浓度(12.9ppm)处于三种自然土壤的LC_(50)值(褐土6.9ppm、红壤12.7ppm、黑土19.2ppm)之间,表明人工土壤具有一定的代表性,用人工土壤进行农药对蚯蚓的毒性研究是可行的.     

甲胺磷、乙草胺和铜单一与复合污染对黑土环境安全的胁迫研究

以黑土为环境介质,通过急性毒性试验法研究了东北黑土区普遍存在的2种农用化学品甲胺磷和乙草胺与重金属Cu对赤子爱胜蚓(Eiseniafoetida)的单一与复合毒性效应.单一毒性试验结果表明,3者对蚯蚓均有毒性,顺序为甲胺磷>乙草胺>Cu.复合毒性实验结果表明,2种有机农药与重金属Cu复合毒性效应十分复杂,与不同的浓度组合及染毒历时有关,一般随时间的延长,毒性加剧.2种有机农药通过不同途径毒害蚯蚓,复合毒性效应表现为协同作用.可见,3者对土壤生态系统环境安全性和土壤健康质量存在潜在危害,同时这几种污染物的共存进一步加大了潜在危害性,且复合毒性效应与各组浓度组合及污染暴露时间密切相关.     

氯苯和邻二氯苯的蚯蚓急性毒性研究

文章以赤子爱胜蚓(Eisenia foetida)滤纸急性毒性实验研究氯苯和邻二氯苯对蚯蚓的单一和联合毒性效应。单一毒性实验发现,蚯蚓死亡率和氯苯与邻二氯苯的曝露浓度显著正相关(P<0.05),其48 h LC50分别为5.680 mL/L和2.750 mL/L,表明氯苯的毒性小于邻二氯苯;同时通过观察可知,氯苯以皮肤渗入赤子爱胜蚓体内的毒性效应高于邻二氯苯;另外,实验期间,蚯蚓的体重明显下降,且与污染物浓度呈一定的线性关系(氯苯R2=0.780和P<0.05)。联合毒性实验发现,氯苯和邻二氯苯共存时蚯蚓的死亡率增加,表明氯苯和邻二氯苯复合污染时两者的毒性呈协同作用。可见,氯苯和邻二氯苯污染对土壤生态系统安全和土壤健康质量存在较大的威胁,同时这两种污染物的共存进一步加大了潜在危害性,且复合毒性效应与各组浓度组合密切相关。     

土壤锑胁迫下赤子爱胜蚓在个体和细胞水平的毒性效应

随着锑(Sb)矿的开采,Sb及其化合物对矿区周围生物暴露风险增大,Sb污染研究在国内外日益受到重视. 为阐明矿区Sb污染土壤对周边生物的毒性效应,本文通过向人工土壤添加焦锑酸钾(KSbO₆H₆)模拟受污染土壤,分别探究了Sb对土壤无脊椎模式生物——赤子爱胜蚓(Eisenia fetida)存活、Sb富集、总蛋白、抗氧化系统酶、丙二醛(malondialdehyde, MDA)的影响,并利用生物标志物响应指数(biomarker response index, BRI)对Sb胁迫下蚯蚓的毒性效应进行综合评价. 结果表明:①蚯蚓死亡率与土壤Sb浓度和暴露时间剂量效应关系明显,经计算蚯蚓56 d LC₅₀为4 380.37 mg/kg. ②蚯蚓对Sb仅有少量吸收,最高处理组(12 800 mg/kg)在暴露56 d后Sb富集量仅为213 mg/kg. ③超氧化物歧化酶(superoxide dismutase, SOD)、过氧化物酶(peroxidase, POD)、MDA在暴露28 d内呈现先升高后降低的倒“U”型变化,过氧化氢酶(catalase, CAT)总体呈现“上升—下降—上升—下降”的变化趋势;总蛋白随时间和处理水平增加呈现不断下降趋势. ④在暴露期间共计24个含Sb处理组中,20个处理受到中等及以下水平健康影响,仅有4个处理组BRI小于2.5,属于严重健康影响. 研究显示,总蛋白、SOD、CAT、POD、MDA均对Sb比较敏感,Sb对赤子爱胜蚓的毒性效应不强,该研究结果可为我国土壤Sb污染提供关键毒理学数据.      

土壤整体质量的生态毒性评价

土壤样品采自沈阳西部污灌区 .进行了污染物 (重金属和矿物油 )含量分析和生态毒性试验 .重金属采用原子吸收分光光度仪测定 ,矿物油采用紫外分光光度计测定 .生态毒性试验分别参照国际标准组织 (ISO)和OECD指南 ,进行了植物毒性试验、蚯蚓毒性试验和蚕豆根尖微核试验 .植物试验以小麦种子发芽根伸长抑制率为试验终点 ,试验周期50h ,蚯蚓毒性试验以蚯蚓死亡率、体重增长抑制率为试验终点 ,试验周期28d .土壤中矿物油含量在145mg/kg～1121mg/kg ,重金属Cd为0.34mg/kg～1.81mg/kg .土壤对植物和蚯蚓显示不同程度的毒性效应 ,土壤的蚕豆根尖微核率明显高于对照 .种子发芽根伸长抑制率为2.0%至-35.1% ,蚯蚓死亡率为0%～40%.体重增长抑制率由14d的-2.3%～-19.4%在28d增加到-2.1%～10.7% ,蚕豆根尖微核率最高达6.62/100.研究表明 ,土壤中的污染物积累较低 ,但具有明显的生态毒性 .     

土壤铅镉铬暴露下赤子爱胜蚓的回避行为和急性毒性

为了评价土壤重金属污染的生态毒理学效应,根据OECD(经济合作与发展组织)试验指南,研究了人工土壤中Pb、Cd、Cr暴露下赤子爱胜蚓(Eisenia fetida)的回避行为和急性毒性. 回避试验结果表明:赤子爱胜蚓产生完全回避反应的土壤w(Pb)、w(Cd)、w(Cr)分别为2 000、120、120 mg/kg. 急性毒性试验的结果表明,土壤Pb、Cd、Cr对赤子爱胜蚓14 d LD₅₀(半数致死浓度)的分别为2 526.05、362.83、229.44 mg/kg. 在检测Pb、Cd和Cr污染土壤时,赤子爱胜蚓回避试验的灵敏度要高于急性毒性试验. 该研究结果揭示出,赤子爱胜蚓的回避行为指标能够成为土壤生态系统风险评价和毒性效应研究的生物标志物预警指标.      

硫丹对蚯蚓存活、生长和肠胃线粒体超微结构的影响

通过人工土壤法对蚯蚓进行14d的急性暴露,研究了硫丹对蚯蚓存活、生长的影响;试验结束后,从硫丹剂量为0.5mg·kg-1和5 mg·kg-1的处理中挑选蚯蚓制作超薄切片,观察肠、胃部线粒体超微结构的变化.结果表明,硫丹对蚯蚓有较强的毒性作用,14d的LC50为6.52mg·kg-1.试验期间硫丹对蚯蚓的生长有显著的抑制作用,生长抑制率随硫丹剂量和暴露时间增加而增大.蚯蚓肠胃部的线粒体对硫丹有较强的敏感性,在非致死剂量下超微结构的损伤程度随硫丹剂量增加而加重.     

Evaluation of genotoxicity of combined soil pollution by cadmium and phenanthrene on earthworm

The DNA-damaging effects of the combined pollution of heavy metal and organic contamination on earthworms were evaluated by single cell gel electrophoresis （SCGE） assay. Earthworms Eisenia andrei were exposed to single or combined test compounds in different doses of cadmium （Cd） 5, 10, 50 mg/kg and phenanthrene （Phe） 0.5, 2.5, 12.5 mg/kg with a treatment of 14 d. In SCGE assay, isolated coelomcytes and electrophoresis were employed to determine DNA damage degree after a 14-d treatment by test compounds. The results showed that there was a significant statistical difference between earthworms treated with Cd combined Phe with them treated alone with Cd or Phe. The Olive tail moment （OTM） of SCGE assay using earthworm coelomcytes appears to be a sensitive biomarker for evaluating exposure to genotoxic compounds. These tests also revealed that the interaction between Cd and Phe to DNA damaging effects was negative, and was strongly dependent on the concentration of pollution. This study corresponds to exploratory phase in order to reveal interaction effects of heavy metal and organic contamination on earthworms and then to set up more in-depth analysis to increase progressively the understanding of the genotoxicity mechanisms involved.