Experimental carcinogenesis of the lung. II. Influence of phenols in the production of carcinoma.

The acidic Fractions (including phenols) were separated from two somewhat different coal tars. Various blends and an original tar produced aerosols to which 5 groups of male C3H/HeJ mice were exposed 2 hours, 3 times weekly, for 55 weeks. Animals were killed at intervals. The lungs and tracheas of all mice were examined grossly and microscopically for neoplasms or relevant morphologic changes. After 46 weeks, 32 survivors in groups 2 and 4, which received similar aerosols containing phenols, had 4 incidences of adenocarcinoma, 19 of intrabronchial adenoma, and 10 of squamous metaplasia. In 20 survivors of group 3, which received the same far without phenols, there was no incidence of adenocarcinoma, 11 had intrabronchial adenoma and 2 had squamous metaplasia.