The comet assay has been extensively used in biomonitoring studies. To avoid intra-experimental variability, the incorporation of assay controls in each work session for data normalization has been suggested by some authors but has never been thoroughly analyzed. The aim of this study was to address the impact of data normalization in the results of a biomonitoring study using different normalization models. Human peripheral blood mononuclear cells (PBMC) from 140 healthy individuals were analyzed using the alkaline and FPG-modified version of the comet assay across seven different work sessions. In addition to negative standards, methyl methanesulfonate (MMS) and Ro 19-8022 plus light treated PBMC, were also included in the assay as positive standards. To verify the impact of data normalization, some demographic, lifestyle and environmental exposure-related variables were selected. Significant associations with independent study variables were observed using normalized comet endpoints, as opposed to raw data. After normalization, levels of DNA strand breaks were significantly higher among males and older individuals (>71 years), while net FPG-sensitive sites were positively related to smoking habits and environmental exposures (i.e. air pollution and bottled water consumption). This study highlights how the normalization strategies can influence the statistical results of a human biomonitoring study and lead to different data interpretations.

中文翻译：

---

彗星试验数据标准化对人类生物监测研究结果的影响

彗星试验已广泛用于生物监测研究。为了避免实验内的变异性，一些作者建议在每个工作会话中加入化验控制以进行数据标准化，但从未进行过彻底的分析。本研究的目的是解决数据标准化对使用不同标准化模型的生物监测研究结果的影响。来自 140 名健康个体的人外周血单核细胞 (PBMC) 使用碱性和 FPG 改良版彗星试验在七个不同的工作时段进行分析。除了阴性标准，甲磺酸甲酯 (MMS) 和 Ro 19-8022 加上光处理的 PBMC，也作为阳性标准包括在测定中。为了验证数据标准化的影响，一些人口统计，选择了生活方式和环境暴露相关变量。与原始数据相反，使用标准化彗星终点观察到与独立研究变量的显着关联。归一化后，男性和老年人（>71 岁）的 DNA 链断裂水平显着更高，而净 FPG 敏感位点与吸烟习惯和环境暴露（即空气污染和瓶装水消耗）呈正相关。这项研究强调了标准化策略如何影响人类生物监测研究的统计结果并导致不同的数据解释。男性和老年人（>71 岁）的 DNA 链断裂水平显着更高，而净 FPG 敏感位点与吸烟习惯和环境暴露（即空气污染和瓶装水消耗）呈正相关。这项研究强调了标准化策略如何影响人类生物监测研究的统计结果并导致不同的数据解释。男性和老年人（>71 岁）的 DNA 链断裂水平显着更高，而净 FPG 敏感位点与吸烟习惯和环境暴露（即空气污染和瓶装水消耗）呈正相关。这项研究强调了标准化策略如何影响人类生物监测研究的统计结果并导致不同的数据解释。