The carcinogenicity of wood soot from the chimney of a smoked sausage factory.

In the course of a study of the estrogenic activity ot plant materials in this laboratory (21) our attention was drawn to the fact that wood soot extracts have a slight estrogenic activity. It seemed of interest to ascertain whether this estrogenic activity is combined with a carcinogenic action. In 1922 Passey (4) reported that extracts of soot collected from chimneys in England can evoke skin warts in animals. The well-known occurrence ot scrotal carcinoma in chimney-sweeps, first described by Percivall Pott (1775), has been associated with the formation of carcinogenic substances in burning coal. Brownlie (1) has suggested that organic products of the decomposition of carbonaceous materials under high temperature conditions (especially bituminous coal, petroleum oil, coal-tar pitch, briquettes, illuminating gas, smoked foods, shale oils, etc.) can act a': carcinogens. In numerous papers Roffo (5-17) has asserted that sometimes carcinogenic substances are formed by the burning at high tcmperatures of tobacco and coffee. Widmark (20) produced mammary adeno carcinomas in 40 per cent of female mice by applying extracts of roasted (275 ~ C.) horse muscle, coffee, and brown butter. The spontaneous frequency of malignant tumors among his females was, however, rather high (10 per cent). Liu and t-Iu (3) produced papillomas in 4 out of 230 mice with tar obtained by destructive distillation of various vegetable foodstuffs. Dickens and Weil-Malherbe (2) produced 1 experimental skin papilloma and 8 pulmonary adenomas by means of wood smoke in 17 mice. Rats fed with smoked fish and meat did not, however, develop tumors during 20 months of observation. The experiments of Steiner, Steele, and Koch (18) suggest the possible carcinogenicity of overcooked meat, heated cholesterol, acrolein, and heated sesame oil. Whereas heating up to 300 ~ C. did not produce carcinogenic substances, sesame oil that had been heated to 350 ~ C. was carcinogenic in 3 out of 9 mice. In view of these findings we undertook to ascertain: (a) whether soot from wood is carcinogenic in our rat and mouse strains, which normally have a natural tumor incidence of about 0.1 per cent; (b) whether the daily consumption of unlimited quantities of smoked sausage is carcinogenic for animals. TECHNIC