CHAPTER 22: Effects of Tobacco Smoking on Micronucleus Frequency Check Access

Tobacco smoke contains numerous genotoxic carcinogens (e.g. polycyclic aromatic hydrocarbons, heavy metals, tobacco-specific nitroso-compounds, aromatic amines) and causes more than 7 million deaths globally per year. In addition to the lungs, tumor induction was found in several other organs of smokers, in particular in the bladder, larynx and pharynx. In vitro studies with mammalian cell lines and experiments with laboratory rodents found that individual smoke constituents and also smoke condensates cause the formation of micronuclei (MN) and other biomarkers of DNA damage. Human studies with cigarette smokers detected MN induction in lymphocytes and also in exfoliated cells from the mouth, bladder and cervix, but clear positive results were confined to heavy smokers. Furthermore, positive results were observed with water pipe smokers (two studies), while negative results were reported in a study with tobacco free electronic cigarettes. Data concerning cigar and pipe smoking are not available at present. There is some evidence of potential synergistic effects of smoking in combination with occupational exposures to other genotoxins, but more investigations are required to draw firm conclusions. Also combination effects with alcohol consumption and the impact of age and body weight on MN formation have only been poorly investigated.