C市枯水期饮用水中有机污染物分析及对肝细胞DNA损伤的研究

An analysis of the organic extracts from source water and drinking water in city C and the effects on DNA damage in primary hepatocytes in rats

目的 了解城市饮用水环境中有机污染物状况及其对肝细胞的遗传毒性。方法 用气 质联用仪毛细管色谱柱分离分析技术 (GC MS)定性分析C市以嘉陵江和长江为水源的A、B、C、D、E 5个水厂枯水期的水源水与出厂水中有机提取物并用单细胞凝胶电泳实验检测了其对原代大鼠肝细胞DNA的损伤 ,观察比较DNA迁移长度与拖尾细胞百分率。结果 定性分析共检出有机物 98种 ,其中水源水为 60种 ,出厂水为 5 8种 ,污染物主要包括 :酯类、酮类、酚类、杂环和苯及其衍生物等。水源水样品中以长江为水源的C、D、E厂在 2 5 0ml时肝细胞DNA迁移长度和细胞拖尾百分率与对照相差显著 (P <0 .0 1) ,以嘉陵江为水源的A、B厂在 5 0ml即可相差显著 (P <0 .0 1)。而全部出厂水样品诱导的DNA损伤在 5 0ml均与对照相差显著 (P <0 .0 1)。结论 C市主城区各水厂水源水与出厂水均已受到有机物的污染 ,嘉陵江的污染重于长江。且各水样的有机提取物在一定范围内均可诱导原代大鼠肝细胞DNA损伤 ,出厂水引起的DNA迁移长度大于水源水 。

Objective To investigate the effects of the polluted organic substances in urban water environment and genetoxicity of the organic pollutants in drinking water on DNA damage in primary cultured hepatocytes in rats. Methods Qualitative analysis of the organic extracts from source water and drinking water in five waterworks in city C with GC/MS was conducted and the effects of organic extracts on DNA damage in primary cultured hepatocytes in rats were tested with single cell gel electrophoresis assay. Comet length means and percentage of tail cell were observed. Results A total of 98 organic pollutants were detected in all samples including 60 in source water and 58 in drinking water. The pollutants were mainly esters, ketons, phenols, benzenes and the derivatives. Comet length means was found to be significantly higher ( P <0.01) in source water from C, D, E waterworks at 250 ml/tube and A, B waterworks at 50 ml/tube compared to control sample. DNA damage induced by organic extracts from all drinking water samples was found at 50 ml/tube ( P <0.01). Conclusion Source water and drinking water in city C are polluted by organic substances. Jialing river is polluted more seriously than Yangtze river. DNA damage induced by organic extracts from drinking water and source water in city C can be found and comet length means from drinking water is longer than that from source water, suggesting that chlorinated disinfection can enhance DNA damage induced by organic extracts.