Feng Shaolong, Kong Zhiming, Wang Xinming, Zhao Lirong, Peng Pingan
The State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Chemosphere. 2004 Aug;56(5):457-63. doi: 10.1016/j.chemosphere.2004.02.010.
Imidacloprid [1-(6-chloro-3-pyridylmethyl)-N-nitro-imidazolidin-2-ylideneamine] and RH-5849 [2'-benzoyl-l'-tert-butylbenzoylhydrazinel] are two pesticides used in China since 1992. In the present study we conducted acute toxicity test, micronucleus (MN) test and comet assay of the two pesticides on amphibian, Rana N. Hallowell, a sensitive organism suitable for acting as the bio-indicator of aquatic and agricultural ecosystems. The values of LC50-48 h of imidacloprid were found to be 165 mg l(-1) for tadpoles of Rana limnocharis and 219 mg l(-1) for tadpoles of Rana N. Hallowell. On the other hand, RH-5849 showed no acute toxicity to tadpoles during the 96 h exposure even it was saturated in the test solutions. There were significant differences in the MN frequencies between the negative controls and the treated groups at the dose of 8 mg l(-1) for imidacloprid (p < 0.05) and 40 mg l(-1) for RH-5849 (p < 0.01). Comet assay found significant differences (p < 0.01) in the distributions of DNA damage grades between the negative controls and groups treated in vitro with 0.05, 0.1, 0.2 and 0.5 mg l(-1) of imidacloprid and 5, 25, 50 and 100 mg l(-1) of RH-5849, respectively. DNA damage scores increased with the exposure levels of the two pesticides and dose-effect relationships were observed for both imidacloprid (r2 = 0.92) and RH-5849 (r2 = 0.98). The MN test and comet assay revealed potential adverse effects of the two pesticides on DNA in the erythrocytes of amphibians in aquatic and agricultural ecosystems.
吡虫啉[1-(6-氯-3-吡啶基甲基)-N-硝基咪唑烷-2-亚基胺]和RH-5849[2'-苯甲酰基-1'-叔丁基苯甲酰肼]是自1992年以来在中国使用的两种农药。在本研究中，我们对两栖动物泽陆蛙（一种适合作为水生和农业生态系统生物指示物的敏感生物）进行了这两种农药的急性毒性试验、微核（MN）试验和彗星试验。吡虫啉对泽陆蛙蝌蚪的48小时半数致死浓度（LC50-48 h）值，泽陆蛙蝌蚪为165 mg l(-1)，沼蛙蝌蚪为219 mg l(-1)。另一方面，RH-5849在96小时暴露期间对蝌蚪没有急性毒性，即使在测试溶液中已达到饱和。在吡虫啉剂量为8 mg l(-1)（p < 0.05）和RH-5849剂量为40 mg l(-1)（p < 0.01）时，阴性对照组和处理组之间的微核频率存在显著差异。彗星试验发现，阴性对照组与分别用0.05、0.1、0.2和0.5 mg l(-1)吡虫啉以及5、25、50和100 mg l(-1) RH-5849体外处理的组之间，DNA损伤等级分布存在显著差异（p < 0.01）。DNA损伤评分随两种农药的暴露水平增加而增加，并且观察到吡虫啉（r2 = 0.92）和RH-5849（r2 = 0.98）均存在剂量-效应关系。微核试验和彗星试验揭示了这两种农药对水生和农业生态系统中两栖动物红细胞DNA的潜在不利影响。
