Cigarette smoking and lung disease.

Despite major changes in the patterns of cigarette consumption in the United States in the last two decades, cigarette smoking remains a widespread practice. Many studies show a strong association between cigarette smoking and chronic obstructive lung disease, but only recently have mechanisms been elucidated to explain this association, particularly in the case of emphysema. The exact mechanism of chronic bronchitis is less well defined. The mortality rate for lung cancer continues to increase in this country, particularly among women. Compelling evidence associates lung cancer with cigarette smoking, although animal models have not been very successful. Recently, concern has been raised about the effects of passive smoking. There are substantial data available to suggest that passive smoking results in pulmonary infections and abnormal pulmonary function in children of smokers. The data are less clear-cut for pulmonary functional impairment in adults and for lung cancer in the spouses of smokers. Although the concept of "safer" cigarettes has been widely accepted by the American public, these cigarettes may not be as safe as is widely assumed. Clearly, they are far inferior to total smoking cessation. Nevertheless, smoking cessation remains difficult for many Americans, despite a number of methods that have been used to help smokers quit. Nicotine chewing gum, which has recently become available for use in the United States, has shown some efficacy in helping well-motivated, nicotine-dependent smokers quit smoking. Although some inroads have been made into the occurrence of smoking related diseases in the United States, many unnecessary deaths continue to occur.