Smoking Kills: Experimental Proof from the Lung Health Study

In 1938, Raymond Pearl reported in Science that tobacco smoking shortened the life span (1). In a study of determinants of longevity in East Baltimore families, he developed life tables for smokers and nonsmokers, using data from 6813 men, most of whom were smokers. Pearl showed that life span after age 30 years for white men was reduced by about 10 years in “heavy smokers” compared with nonsmokers (Figure). Longevity was also lower for “moderate smokers.” In retrospect, this powerful observation received surprisingly little attention, even though an effect of this magnitude on total mortality, a crude but integrating measure of population health, must have come from strong increments in risk for death from specific diseases. George Seldes, an investigative reporter who championed tobacco control, attributed the limited media coverage of the finding to the influence of the tobacco industry (2).

Further studies of smoking and overall mortality were not reported until the 1950s, when early findings of cohort studies initiated to prospectively investigate the risks of lung cancer and other diseases associated with smoking were published. By 1964, the first U.S. Surgeon General's Report on smoking and health (3) had reviewed the results of 7 cohort studies, including the study of British physicians for which 50-year findings were recently reported (4). All of the studies showed increased risk for dying in smokers compared with nonsmokers, and some studies showed that the risk increased with the number of cigarettes smoked. The 1964 report carefully discussed the possibility that either …