Cigarette smoke is the single known, leading preventable cause of lung cancer. In 2006, an estimated 170,000 cancer deaths in the United States were caused by tobacco smoke. Approximately 45 million Americans are current smokers, of which nearly 11 million, or 24%, are between the ages of 18 and 44. If this current trend continues, the 2030 global death toll due to smoking will exceed 9 million. On average, adults who smoke cigarettes die 14 years earlier than nonsmokers.
It is known that chemical carcinogenesis is a multistage pro-cess involving initiation, promotion, and progression. Initia-tion, the critical first step in carcinogenesis, requires the binding of active chemical carcinogens to genomic DNA and forming DNA adducts, which result in mutation and consequent cancer Therefore, the detection and quantification of DNA adducts is an important, fundamental, early indicator of cancer risk.