6-Nitrochrysene is a potent tumorigen in newborn mice

A newborn mouse (BLU:Ha) lung adenoma bioassay demonstrated that 6-nitrochrysene was a highly potent tumorigen. It induced 100% incidence of lung tumors and a 150-fold increase in their number (20.84 tumors/mouse) at the lowest dose level tested (total dose: 38.5 micrograms/mouse). 70% of the 6-nitrochrysene treated mice had malignant lung tumors (adenocarcinomas). Lymphomas and nodular hyperplasia of the liver were also observed in treated, but not control, animals. The tumorigenicity of 6-nitrochrysene relative to other polynuclear aromatic hydrocarbons and their mononitro-derivatives has been discussed.