[The carcinogenic activity of small concentrations of nitrosodimethylamine when inhaled]

In experiments on Balb/c mice and Wistar rats the authors have studied the carcinogenic activity of nitrosodimethylamine (NDMA) in daily inhalations of the drug in concentrations of 0.005 mg/m3 and 0.2 mg/m3 during 17 months for mice and 25 months for rats. In the concentration of 0.2 mg/m3 tumors would arise considerably earlier and in larger amounts than in control animals, as well as in animals inhaling NDMA in the concentration of 0.005 mg/m3 and not differing in this respect from control animals.