Changes in overwrap and butt length of American filter cigarettes. An influence on reported tar yields

Reported tar and nicotine yields of cigarettes, determined by official government assays, are used by the public and by health professionals to evaluate and compare cigarette brands. Many smokers use these reported values to help them decide what brands to smoke. In addition, health-care professionals often encourage smokers to switch to presumably less hazardous low tar brands. Health researchers also use reported yields to examine changes in smoking behavior with changes in cigarette brands and health hazards associated with smoking certain brands. Unfortunately, some of these reported values are misleading. The present study examined the relationship between reported tar yields and changes in physical characteristics (overwrap length and butt length) of filter cigarettes. Of the 161 American filter cigarette brands examined, 18% showed an inverse relationship between changes in overwrap length and reported tar yield. When this relationship exists, reported yields may be misleading and inaccurate. To improve the meaningfulness of the reported tar and nicotine yields, the number of puffs taken by smoking machines on each cigarette should be reported.