Université de Toulouse, INPT, UPS, ECOLAB (Laboratoire Ecologie Fonctionnelle), Ecole Nationale Supérieure Agronomique de Toulouse (ENSAT), Castanet Tolosan, France.
Aquat Toxicol. 2011 Jan 17;101(1):126-34. doi: 10.1016/j.aquatox.2010.09.014. Epub 2010 Sep 29.
When heavy rainfall follows herbicide application, the intense surface runoff causes stream water contamination. Aquatic organisms are then briefly exposed to a complex mixture of contaminants. The aim of the present study is to investigate the genotoxic impact of such events on fish. A model fish, the Crucian carp (Carassius carassius) was exposed in controlled conditions, for 4 days, to water sampled daily in the Save River (France). The watershed of this stream is representative of agricultural areas in south-west France. Three hydrological conditions were compared: basal flow, winter flood, and spring flood. Chemical analysis of the water samples confirmed the higher contamination of the spring flood water, mainly explained by a peak of metolachlor. Genotoxicity was evaluated by micronucleus (MN) test and comet assay in peripheral erythrocytes. A significant increase in DNA breakdowns compared to controls was detected by the comet assay for all conditions. Exposure to spring flood water resulted in the highest damage induction. Moreover, induced chromosomal damage was only detected in this condition. In addition, fish were exposed, for 4 days, to an experimental mixture of 5 herbicides representative of the spring flood water contamination. Fish exhibited moderate DNA damage induction and no significant chromosomal damage. The mutagenicity induced by field-collected water is then suspected to be the result of numerous interactions between contaminants themselves and environmental factors, stressing the use of realistic exposure conditions. The results revealed a mutagenic impact of water contamination during the spring flood, emphasizing the need to consider these transient events in water quality monitoring programs.
当除草剂施后紧接着下大雨时，强烈的地表径流会导致溪流水污染。水生生物随后会短暂暴露于复杂的污染物混合物中。本研究旨在调查此类事件对鱼类的遗传毒性影响。选用模式鱼——鲫鱼（Carassius carassius），在受控条件下暴露于每天从法国萨夫河（Save River）采集的水样中，持续 4 天。该溪流流域代表了法国西南部的农业区。比较了三种水文条件：基础流量、冬季洪水和春季洪水。对水样的化学分析证实，春季洪水的污染程度更高，主要归因于甲草胺的峰值。通过外周红细胞的微核（MN）试验和彗星试验评估遗传毒性。与对照相比，所有条件下的彗星试验均检测到 DNA 断裂明显增加。暴露于春季洪水导致最高的损伤诱导。此外，仅在此条件下检测到诱导的染色体损伤。此外，鱼类还暴露于实验性的 5 种混合除草剂中，这些除草剂代表了春季洪水的污染。鱼类表现出中等程度的 DNA 损伤诱导，且没有明显的染色体损伤。因此，野外采集水样的致突变性被怀疑是污染物本身与环境因素之间的众多相互作用的结果，这强调了在暴露条件下使用现实的暴露条件的必要性。研究结果揭示了春季洪水中水污染的致突变影响，强调了在水质监测计划中需要考虑这些短暂事件。
