Grup de Mutagènesi, Departament de Genètica i de Microbiologia, Facultat de Biociències, Edifici Cn, Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain.
Water Res. 2010 Apr;44(8):2638-46. doi: 10.1016/j.watres.2010.01.026. Epub 2010 Feb 10.
Drinking water contains disinfection byproducts, generated by the interaction of chlorine (or other disinfecting chemicals) with organic matter, anthropogenic contaminants, and bromide/iodide naturally present in most source waters. One class of these chemicals is the halogenated acetaldehydes (HAs), identified in high quantities when ozone is used as primary or secondary disinfectant. In this study, an analysis of the genotoxic potential of two HAs, namely tribromoacetaldehyde (TBA) and chloral hydrate (CH) has been conducted in human cells (TK6 cultured cells and peripheral blood lymphocytes). The comet assay was used to 1) measure the induction of single and double-strand DNA breaks, 2) evaluate the capacity of inducing oxidative DNA damage, and 3) determine the DNA repair kinetics of the induced primary genetic damage. In addition, chromosome damage, as a measure of fixed damage, was evaluated by means of the micronucleus test. The results of the comet assay show that both compounds are clearly genotoxic, inducing high levels of DNA breaks, TBA being more effective than CH. According to the comet results, both HAs produce high levels of oxidized bases, and the induced DNA damage is rapidly repaired over time. Contrarily, the results obtained in the micronucleus test, which measures the capacity of genotoxic agents to induce clastogenic and aneugenic effects, are negative for the two HAs tested, either using TK6 cells or human peripheral blood lymphocytes. This would indicate that the primary damage induced by the two HAs is not fixed as chromosome damage, possibly due to an efficient repair or the death of damaged cells, which is an important point in terms of risk assessment of DBPs exposure.
饮用水中含有消毒副产物，这些副产物是由氯（或其他消毒剂）与有机物、人为污染物以及溴/碘自然存在于大多数水源中的物质相互作用产生的。这些化学物质中有一类是卤代乙醛（HAs），当臭氧被用作主要或次要消毒剂时，会大量生成。在这项研究中，我们在人类细胞（TK6 培养细胞和外周血淋巴细胞）中分析了两种 HAs（三溴乙醛（TBA）和水合氯醛（CH））的遗传毒性潜力。彗星试验用于 1）测量单链和双链 DNA 断裂的诱导，2）评估诱导氧化 DNA 损伤的能力，3）确定诱导的原发性遗传损伤的 DNA 修复动力学。此外，通过微核试验评估染色体损伤作为固定损伤的指标。彗星试验的结果表明，这两种化合物都具有明显的遗传毒性，可诱导高水平的 DNA 断裂，TBA 比 CH 更有效。根据彗星试验结果，两种 HAs 均产生高水平的氧化碱基，并且诱导的 DNA 损伤随时间迅速修复。相反，在微核试验中，该试验用于测量遗传毒性剂诱导断裂和非整倍体效应的能力，对于两种测试的 HAs 均得到阴性结果，无论是使用 TK6 细胞还是人外周血淋巴细胞。这表明，两种 HAs 诱导的原发性损伤不会固定为染色体损伤，这可能是由于有效的修复或受损细胞的死亡，这在评估 DBPs 暴露风险方面是一个重要的问题。
