Self-regulation of smoking intensity. Smoke yields of the low-nicotine, low-'tar' cigarettes.

It has been assumed for some time that the 'tar' and nicotine data for individual cigarette brands, as reported by the Federal Trade Commission (FTC), do not adequately reflect the levels of exposure to toxic and carcinogenic agents in the smoke. The trend of decreasing 'tar' and nicotine yields of the sales-weighted average US cigarettes was not followed by a proportionate decline of lung cancer incidence and mortality rates. Utilizing a 'tobacco smoke inhalation testing system', we determined smoking profiles for four men and four women who smoked low-nicotine cigarettes ( < or = 0.8 mg/cigarette according to FTC), and for two men and two women who smoked cigarettes with medium-nicotine (0.9-1.2 mg) yields. The recorded smoking profiles were programmed into a smoking machine to establish mainstream smoke yields for 'tar', nicotine, benzo[a]pyrene and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. The analytical data obtained for each smoker's cigarette were compared with corresponding measurements in the smoke from the same cigarette brand that was generated by machine-smoking under the standardized FTC conditions (1 puff of 2 s duration and 35 ml volume drawn once/min). Significant increases in terms of total volume of smoke inhaled and exposures to 'tar', nicotine, and lung carcinogens were measured (2- to 4-fold) and, because of smokers' compensation for low nicotine delivery, much greater overall exposure resulted from smoking low-nicotine cigarettes. Although these measurements were obtained for a limited number of smokers, they strongly indicate that both low- and medium-nicotine cigarettes are being smoked much more intensely than would be implied from the FTC-data. Therefore, there is an urgent need to accurately quantify the exposure of consumers of the various types of cigarettes to toxic and carcinogenic agents.