Cigarette smoking is a major cause of lung disease. In particular, heavy cigarette smokers are predisposed to the development of lung cancer and two forms of chronic lung disease, chronic bronchitis and emphysema. It is generally accepted that smoking cessation is a desirable preventative measure for health maintenance. Unfortunately, nearly two thirds of smokers who desire to quit are unable to achieve complete abstinence. For them, reducing lifetime exposure to cigarette smoke may be an alternative preventative medicine strategy. Current approaches to smoking reduction are basically ineffective. Few smokers can sustain nicotine reduction, achieved by smoking fewer cigarettes or by switching to lower tar cigarettes. Smokers who do reduce or switch tend to compensate for reduced nicotine yield by puffing more frequently per cigarette thereby probably negating any health benefits. In a previous uncontrolled pilot study of heavy smokers, we examined the role of alternative nicotine delivery using 2 mg nicotine gum to reduce the risk of cigarette smoke induced lung disease. Our results in this short term (8 weeks) study indicated that smoking reduction was associated with an improvement in several of the inflammatory features present in the lower respiratory tract of normal smokers. This investigation will address several key questions: 1)How important is alternative nicotine delivery in smoking reduction? Could favorable results have been obtained had smokers reduced on their own or switched to lower tar cigarettes? 2)Can smoking reduction be maintained for a six month period? 3)Will the cellular, biochemical and morphological improvements achieved in a previous study persist long term?