Background: Tobacco smoke contains many oxidant s and free radicals that can cause damage to lipids, proteins, DNA, carbohydrates and other biomolecules. This is a case-control study. Carried out in Khartoum State from December to February 2015. Material and Method: Three ml of venous blood were collected from study population; serum zinc and cadmium was estimated using absorption spectrophotometer. Results: The study results revealed that the mean age of smokers was (26.7±6.3) year and for non smokers was (25.0±7.0) year. The mean±SD of serum zinc and cadmium in smokers respectively were 0.51±0.22 and 0.08±0.040 µg/L. The mean±SD of serum zinc and cadmium in non-smokers were 0.65±0.21and 0.0002±0.0001µg/L respectively. There was a highly significant difference in serum zinc between smokers and non-smokers (p value 0.000, <0.05. Cadmium was significantly higher in smokers compared with non-smokers (p<0.05), the level in smokers being four (4) fold than in non-smokers. In contrast Zn level was significantly reduced in smokers compared with non-smokers (p<0.05). However the Zn was significantly higher in non- smokers than in smokers (p<0.05). The zinc: cadmium ratio was significantly reduced (p<0.001), implying high cadmium: zinc ratio. This ratio was (8.7) times the level in non-smokers. Correlation studies showed negative significant association between Zn and number of cigarette per day (r= -0.748, p<0.01) and between duration of smoking were strongly positively correlated (r= 0.297, p< 0.05). Also significantly positive correlation between Cd and number of cigarettes per day(r= 0.947, p< 0.01) and negative correlation with duration of smoking in years (r= -0.422, p< 0.01). Conclusion: This study concluded that; level of serum cadmium is increased in cigarette smokers and serum zinc decreased. The increased in level of serum cadmium affected by the duration of smoking and number of cigarettes smoked per day. This study appears to provide evidence to show that the convergence of: reduced Zn level, high Cd: Zn ratio, may serve as a simple panel of biomarkers of risk of prostate cancer.
