背景:全球估计有800,000人在职业上暴露于焊接烟雾。先前的研究表明,暴露于此类烟雾与遗传物质的损害和癌症风险增加有关。在这项研究中,我们使用微核试验评估了焊接烟雾对墨西哥焊工口腔粘膜细胞的遗传毒性作用。
方法:我们进行了横截面,n=66(33名外露焊工,和33个健康对照)。收集颊粘膜涂片,用吖啶橙染色,用荧光灯在100x光学放大下观察,单盲观察者计算每2,000个观察细胞的微核和其他核异常的数量。我们比较了微核和其他核异常的频率,和拟合的广义线性模型,以研究核异常和暴露于焊接烟雾之间的相互作用,同时控制吸烟和年龄。
结果:双核细胞和凝聚染色质细胞在病例和对照组之间显示出统计学上的显著差异。微核的频率和其余的核异常(叶状核,固缩症,核溶解,和karyorrhexis)在两组之间没有显着差异。调整吸烟后,回归结果表明,双核细胞的发生可以通过暴露于焊接烟雾加上烟草消耗的存在来预测;对于凝聚染色质细胞,我们的模型表明,暴露于焊接烟雾是唯一可靠的预测因素。
结论:我们的研究结果表明,职业暴露于焊接烟雾的墨西哥焊工的双核和凝聚染色质细胞数量增加。然而,病例和对照组之间的微核和其他核异常的频率没有差异。进一步的研究应该对这个问题有更多的启示。
BACKGROUND: An estimated 800,000 people worldwide are occupationally exposed to welding-fumes. Previous studies show that the exposure to such fumes is associated with damage to genetic material and increased cancer risk. In this study, we evaluate the genotoxic effect of welding-fumes using the Micronucleus Test on oral mucosa cells of Mexican welders.
METHODS: We conducted a cross-sectional, matched
case-control study of n = 66 (33 exposed welders, and 33 healthy controls). Buccal mucosa smears were collected and stained with acridine orange, observed under 100x optical amplification with a fluorescence lamp, and a single-blinded observer counted the number of micronuclei and other nuclear abnormalities per 2,000 observed cells. We compared the frequencies of micronuclei and other nuclear abnormalities, and fitted generalised linear models to investigate the interactions between nuclear abnormalities and the exposure to welding-fumes, while controlling for smoking and age.
RESULTS: Binucleated cells and condensed-chromatin cells showed statistically significant differences between cases and controls. The frequency of micronuclei and the rest of nuclear abnormalities (lobed-nuclei, pyknosis, karyolysis, and karyorrhexis) did not differ significantly between the groups. After adjusting for smoking, the regression results showed that the occurrence of binucleated cells could be predicted by the exposure to welding-fumes plus the presence of tobacco consumption; for the condensed-chromatin cells, our model showed that the exposure to welding-fumes is the only reliable predictor.
CONCLUSIONS: Our findings suggest that Mexican welders who are occupationally exposed to welding-fumes have increased counts of binucleated and condensed-chromatin cells. Nevertheless, the frequencies of micronuclei and the rest of nuclear abnormalities did not differ between cases and controls. Further studies should shed more light on this subject.