The Changing Cigarette and Disease R i s k : Current Status of the Evidence

INTRODUCTION Since the early 1950’s when filter tip cigarettes were first widely introduced, the cigarette has evolved continually through modifications intended to reduce yields of tar and nicotine (U.S. Department of Health and Human Services, 1991). Following the introduction of the filter tip cigarette, sales-weighted averages of tar and nicotine deliveries show a temporal trend of declining yield, which continues to the present (Figure 1). In the face of continued modifications of the cigarette and the seemingly associated changes in exposure of smokers to cigarette smoke components, questions have been raised concerning the implications of the changing cigarette for disease risks in smokers.