Samples of cigarette smoke condensates (CSCs) treated with nitric acid or Chinese cabbage pickles having a high nitrate content strongly mutated Salmonella typhimurium strain TA98; the benzene/ethanol extract after these treatments induced 1800 and 820 revertants, respectively, per mg of extract for strain TA98 in the absence of S9 mix. The major mutagens in these materials were found to be 1-nitropyrene and 1,3-dinitropyrene on the basis of the result of gas chromatography/mass spectrometry and of fluorescence spectra of the samples. The quantity of 1-nitropyrene was 14.5 ng per cigarette for the CSCs treated with nitric acid, and for 11.2 ng for those treated with Chinese cabbage pickles. Similarly, 1,3-dinitropyrene was detected in the CSCs treated with nitric acid or Chinese cabbage pickles at concentrations of 0.38 and approximately 0.1 ng, respectively, per cigarette.