Combined carcinogenic action of chrysotile asbestos dust and N-nitrosodiethylamine on the respiratory tract of Syrian golden hamsters.

The combined carcinogenic activity of intratracheally inoculated Canadian chrysotile asbestos dust and orally or subcutaneously administered NDEA has been studied in long-term experiments in Syrian golden hamsters. In animals treated with asbestos only, no lung tumours developed, and single tracheal or laryngeal papillomas were found in only a very few cases. In animals treated with asbestos and NDEA, a synergistic effect which increased the incidence of lung tumours was observed.