ABSTRACT
Tobacco is the only product legally available in the market even if it is harmful to humans (World Health Organization, 2008). During smoking, a complex mixture of compounds is inhaled into the respiratory system affecting different organs. In 1959, some 400 compounds were known to be present in tobacco leaves and tobacco smoke; today, the gure has risen to more than 4000 (Stedman, 1968). The topic on tobacco and health was discussed and focused on by the public for a long time. There are 44 harmful constituents belonging to 13 different classes of chemical compounds revealed by Hoffmann, hydrocyanic acid, carbon monoxide and nitrogen oxides included; on the other hand, these three constituents are regarded as key controlled target compounds by the FCTC. The biomarkers of these three hazardous constituents reveal evidences that prove themselves and their metabolites present in human bodies.
