Tobacco smoke is known for releasing metals in indoor air of waterpipe/cigarette cafés. However, the worker exposure to metals, and its association with oxidative stress in these cafés are still unclear. To this end, 54 workers and 38 customers from waterpipe/cigarette cafés (the exposed group), 30 workers from non-smoking cafés (the control group 1 (CG_1)) and 32 individuals from the general population (the control group 2 (CG_2)) were selected and toenails samples were then taken from them. Our findings revealed a significant difference in terms of toenail-bounded metal levels between the exposure and control groups (CG_1 and CG_2) (Mann–Whitney U test, P_value < 0.05). This study has also indicated that "type of tobacco" could be considered as a predictor for toenail-bounded heavy metals. Furthermore, our research’s results suggest that toenail-bounded heavy metals are positively and significantly correlated with urinary levels of 8- hydroxy-2′-deoxyguanosine (8-OHdG, as a biomarker for the degradation of deoxyribonucleic acid (DNA) oxidative stress). Therefore, it can be concluded that workers of waterpipe/cigarette cafés are at high risks of adverse health of DNA oxidative degradation.

众所周知，烟草烟雾会在水烟/香烟咖啡馆的室内空气中释放金属。然而，工人接触金属的情况及其与这些咖啡馆氧化应激的关系仍不清楚。为此，来自水烟/香烟咖啡馆的 54 名工人和 38 名顾客（暴露组）、来自无烟咖啡馆的 30 名工人（对照组 1 (CG_1)）和 32 名普通人群（对照组 2 (CG_2)） ））被选中，然后从他们身上采集脚趾甲样本。我们的研究结果显示，暴露组和对照组（CG_1 和 CG_2）之间趾甲边界金属水平存在显着差异（Mann-Whitney U检验， P_值< 0.05）。这项研究还表明，“烟草类型”可以被视为脚趾甲中重金属的预测因子。此外，我们的研究结果表明，脚趾甲结合的重金属与尿中 8-羟基-2'-脱氧鸟苷（8-OHdG，作为脱氧核糖核酸 (DNA) 氧化应激降解的生物标志物）水平呈显着正相关。因此，可以得出结论，水烟/香烟咖啡馆的工作人员面临 DNA 氧化降解不良健康的高风险。