Metals transfer from tobacco to cigarette smoke: Evidences in smokers' lung tissue.

Tobacco use kills millions of people every year around the world. The current level of 11 metals in tobacco was determined and their transfer rate to cigarette smoke was calculated as the difference between the total metal content in cigarettes and the amount present in its ashes. The metals content was also determined in the lung tissue of smokers and non-smokers in order to evaluate the marks that smoking leaves in this tissue. Metals content in tobacco ranged from less than 1μg/g (Co, Cd, Pb, As and Tl) to several hundreds of μg/g (Al, Mn and Ba). The highest transfer rate from tobacco to cigarette smoke was found for Tl (85-92%) and Cd (81-90%), followed by Pb (46-60%) and As (33-44%). Significantly higher levels of As, Cd and Pb were found in the lung tissue of smokers compared to non-smokers, showing that smoking results in an increase of these metals in the lungs and that they contribute to the carcinogenic potential of cigarette smoke. This study presents important data on current metals content in tobacco and its transference to cigarette smoke and provides evidence of their accumulation in smokers' lung tissue.