Experimental production of carcinoma with tobacco products. V. Carcinoma induction in mice with cigar, pipe, and all-tobacco cigarette tar.

Abstract

Summary 1.The present study has compared the carcinogenic activity of different tobacco smoke condensates, including that obtained from cigarettes, cigars, pipes, and all-tobacco cigarettes. The results suggest a somewhat higher degree of carcinogenic activity for cigar and pipe tars than for cigarette tar and a somewhat lesser activity for all-tobacco cigarette tar compared with standard cigarette tar. Some of the differences could be a result of differences in biological variation. 2.A comparison of whole tobacco tar with diluted tobacco tar suggests that dilution of tar accelerates tumor formation, apparently as a consequence of increased absorption of tobacco carcinogens. 3.A comparison of the carcinogenic activity of freshly prepared tar with that of “old” cigarette tar showed no differences in activity. 4.Current experiments are consistent with human epidemiological findings. 5.Present data re-emphasize the viewpoint that tobacco carcinogens are formed during the process of combustion of tobacco and that the amount of tobacco carcinogens formed depends on the temperature reached and the completeness with which the combustion process occurs. 6.Preventive measures directed toward reducing tobacco carcinogens must apply to all tobacco products.