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

作　　者：ZHOU Shi-ping DUAN Chang-qun FU Hui CHEN Yu-hui WANG Xue-hua YU Ze-fen 

机构地区：[1]Laboratory for Conservation and Utilization of Bio-Resource and School of Life Science, Yunnan University, Kunming 650091, China. [2]Department of Basic Courses, Southwestern Forestry College, Yunnan 650224, China

出　　处：《Journal of Environmental Sciences》2007年第7期854-858,共5页环境科学学报（英文版）

基　　金：Preject supported by the New Century Excellent Talents in Chinese Uni-versity (No. NCET-04-0914);the National Natural Science Foundationof China (No. 30640022);Yunnan Natural Sciences Foundations (No.2002C0001Z, 2005C0004Q).

摘　　要：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.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.

关 键 词：CHLORPYRIFOS earthworms avoidance response survival reproduction test 

分 类 号：X53[环境科学与工程—环境工程] S481.8[农业科学—农药学]