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，烟气会在水烟筒/烟吧的室内空气中释放金属。然而，在这些咖啡馆中，工人暴露于金属及其与氧化应激的关系仍不清楚。为此，水烟/烟咖啡厅（暴露人群）的54名工人和38位顾客，非吸烟咖啡厅（对照组1（CG_1））的30名工人和一般人群中的32个人（对照组2（CG_2） ）），然后从脚趾甲样本中取出。我们的研究结果表明，暴露组和对照组（CG_1和CG_2）在趾甲结合金属水平方面存在显着差异（Mann-Whitney U检验，P_值 <0.05）。这项研究还表明，“烟草类型”可被视为趾甲结合重金属的预测因子。此外，我们的研究结果表明，与脚趾甲结合的重金属与尿液中的8-羟基-2'-脱氧鸟苷（8-OHdG，作为降解脱氧核糖核酸（DNA）氧化应激的生物标志物）成正相关且显着相关。因此，可以得出结论，水烟/卷烟咖啡馆的工人处于有害健康的DNA氧化降解的高风险中。