Clearing the smoke: the science base for tobacco harm reduction--executive summary.

Background Tobacco smoke is the cause of the most deadly epidemic of modern times. Smoking causes cancer (for example, lung, oral cavity, oesophagus, larynx, pancreas, bladder, kidney), chronic obstructive pulmonary disease (COPD), myocardial infarction, and stroke. The continuing toll of tobacco use has prompted the search for means of harm reduction for those who cannot or will not stop using tobacco. Numerous products that make implied or explicit claims to reduce the burden of smoking while allowing continued nicotine consumption are now entering the market. This report is concerned with the evaluation of these products. Nearly one quarter of adult Americans—an estimated 47 million people—smoke cigarettes. Although this is far lower than the 42% recorded in 1965, the decline in the rates of smoking among adults appears to have levelled oV during much of the 1990s. In a recent survey, 12.8% of middle school children and 34.8% of high school students reported some form of tobacco use during the month prior to their being interviewed. The vast majority of smokers begin tobacco use during adolescence. However, 70% of smokers say they want to quit and 34% of smokers make an attempt to quit each year. Thus, many but not all tobacco users find it very diYcult to quit and continually expose themselves to known toxic agents.