de Perre Chloé, Murphy Tracye M, Lydy Michael J
Center for Fisheries, Aquaculture, and Aquatic Sciences and Department of Zoology, Southern Illinois University, Carbondale, Illinois, USA.
Environ Toxicol Chem. 2015 Feb;34(2):258-65. doi: 10.1002/etc.2800. Epub 2015 Jan 6.
Despite the extensive use of the neonicotinoid insecticide clothianidin, and its known toxicity to beneficial insects such as pollinators, little attention has been given to its fate under agricultural field conditions. The present study investigated the fate and toxicity of clothianidin applied every other year as a corn seed-coating at 2 different rates, 0.25 mg/seed and 0.50 mg/seed, in an agricultural field undergoing a corn-soybean annual rotation, and conservation tillage. Concentrations were measured in soil, surface runoff, infiltration, and groundwater from 2011 to 2013. Clothianidin was detected at low concentrations in soil and water throughout the 2-yr corn and soybean rotation. Low and no-tillage had little or no effect on clothianidin concentrations. Laboratory toxicity bioassays were performed on nontarget species, including Daphnia magna, Hyalella azteca, Chironomus dilutus, Pimephales promelas and Eisenia fetida. Risk quotients were calculated from clothianidin concentrations measured in the field and compared with the laboratory toxicity bioassay results to assess the environmental risk of the insecticide. The risk quotient was found to be lower than the level of concern for C. dilutus, which was the most sensitive species tested; therefore, no short-term environmental risk was expected for the species investigated in the present study.
尽管新烟碱类杀虫剂噻虫胺被广泛使用，且已知其对传粉昆虫等有益昆虫具有毒性，但在农业田间条件下其归宿却很少受到关注。本研究调查了在进行玉米-大豆轮作且采用保护性耕作的农田中，每隔一年以两种不同用量（0.25毫克/种子和0.50毫克/种子）作为玉米种子包衣施用噻虫胺后的归宿和毒性。在2011年至2013年期间对土壤、地表径流、入渗和地下水中的浓度进行了测量。在为期两年的玉米和大豆轮作期间，土壤和水中均检测到低浓度的噻虫胺。少耕和免耕对噻虫胺浓度几乎没有影响。对包括大型溞、阿氏摇蚊、稀释摇蚊、黑头呆鱼和赤子爱胜蚓在内的非靶标物种进行了实验室毒性生物测定。根据田间测得的噻虫胺浓度计算风险商，并与实验室毒性生物测定结果进行比较，以评估该杀虫剂的环境风险。发现风险商低于所测试的最敏感物种——稀释摇蚊的关注水平；因此，本研究中所调查的物种预计不存在短期环境风险。
