农药对蚯蚓的生长和繁殖毒性及其在生态风险评价中的应用

蚯蚓占了陆生无脊椎生物生物量的绝大部分,是农田生态系统土壤物质循环中的重要一环,且蚯蚓对某些污染物比许多其它土壤动物更为敏感,是陆生生态系统中土壤农用化学品污染的理想指示生物。死亡率是最常用于评估化学品对蚯蚓毒性的参数,但大多数情况下蚯蚓死亡率变化对农用化学品暴露并不敏感,因此急性毒性测试结果并不能为评估化学品对蚯蚓种群危害提供最敏感的风险预测。因此,研究更多可应用于土壤污染评价的蚯蚓生物标志物十分有意义,可对保护整个土壤动物区系的安全阈值设定提供参考。本文从蚯蚓常用毒理学研究方法入手,重点综述了农药对蚯蚓的生长和繁殖毒性效应以及相关毒理学测试指标在农药土壤生物风险评价中的应用,并讨论了影响蚯蚓生态毒理学测试结果的各项因素,最后对该领域未来研究提出了展望和建议。

Effects of Pesticides on the Growth and Reproduction of Earthworm and Its Application in Ecological Risk Assessment

A great proportion of biomass of terrestrial invertebrates is represented by earthworms,which play an important role in mass transfer between terrestrial creatures and soil organisms.Earthworms are more sensitive to certain pollutants than many other soil animals and therefore they are ideal organisms to indicate the soil agrochemicals pollution in terrestrial ecosystem.Mortality is one of the most frequently used parameters to evaluate the toxicity of chemicals on earthworms,however,survival is less sensitive to agricultural products exposure and therefore the acute toxicity test would not provide the most sensitive risk estimate for earthworms in the majority of cases.Under such a background,the search for more suitable earthworm biomarkers used in the ecological risk assessment is very meaningful and the related studies can provide a safety threshold to protect the soil fauna.In this review,the most frequently used earthworm toxicological methods and its application in risk assessment of agrochemicals for soil organisms were introduced,as well as the limitation and impact factors for these methods were discussed.Finally,some suggestions were put forward for this area.