UFZ, Helmholtz Centre for Environmental Research, Department of System-Ecotoxicology, Permoserstraße 15, 04318 Leipzig, Germany; RWTH Aachen University, Institute for Environmental Research (Biology V), Worringerweg 1, 52074 Aachen, Germany.
UFZ, Helmholtz Centre for Environmental Research, Department of Molecular System Biology, Permoserstraße 15, 04318 Leipzig, Germany; University of Leipzig, Institute of Biochemistry, Leipzig, Germany.
Sci Total Environ. 2018 Dec 1;643:1533-1541. doi: 10.1016/j.scitotenv.2018.06.282. Epub 2018 Jul 4.
The European regulatory framework for pesticides generally applies an assessment factor of up to 100 below the acute median lethal concentration (LC50) in laboratory tests to predict the regulatory acceptable concentrations (RACs). However, long-term detrimental effects of pesticides in the environment occur far below the RACs. Here, we explored the metabolic changes induced by exposure to the neonicotinoid insecticide clothianidin in larvae of the mosquito Culex pipiens. We exposed the test organisms to the insecticide for 24 h and then measured the levels of 184 metabolites immediately and 48 h after the pulse contamination. We established a link between the exposure to clothianidin and changes in the level of three specific classes of metabolites involved in energy metabolism, namely, glycerophospholipids, acylcarnitines and biogenic amines. Remarkably, exposure to concentrations considered to be safe according to the regulatory framework (2-4 orders of magnitude lower than the acute LC50), induced longer-term effects than exposure to the highest concentration. These results suggest that a specific detoxification mechanism was only triggered by the highest concentration. We conclude that even very low insecticide concentrations increase the energy demands of exposed organisms, which potentially translates into a decline in sensitive species in the field.
欧洲的农药监管框架通常采用实验室测试中急性半数致死浓度 (LC50) 以下的 100 倍评估因子来预测监管可接受浓度 (RAC)。然而，农药在环境中的长期有害影响远低于 RAC。在这里，我们研究了暴露于新烟碱类杀虫剂噻虫胺对蚊子库蚊幼虫的代谢变化。我们将试验生物暴露于杀虫剂中 24 小时，然后在脉冲污染后立即和 48 小时测量 184 种代谢物的水平。我们建立了暴露于噻虫胺与参与能量代谢的三种特定类别的代谢物水平变化之间的联系，即甘油磷脂、酰基辅酶 A 和生物胺。值得注意的是，暴露于被监管框架认为安全的浓度（比急性 LC50 低 2-4 个数量级）会引起比暴露于最高浓度更长时间的影响。这些结果表明，只有最高浓度才会引发特定的解毒机制。我们得出结论，即使是非常低的杀虫剂浓度也会增加暴露生物的能量需求，这可能会导致野外敏感物种的减少。
