Carcinogenesis
-
Comparative Study
Preformed tobacco-specific nitrosamines in tobacco--role of nitrate and influence of tobacco type.
Fifty-five types of commercial cigarettes on the open market in the FRG and several samples of pure tobacco types were analyzed for preformed tobacco-specific nitrosamines (TSNA) and nitrate in the tobacco. For the cigarette tobaccos the observed range for N'-nitrosonornicotine (NNN) was 50-5316 ng/cigarette and for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) from not detected (less than 50 ng/cigarette) to 1120 ng/cigarette. Nitrate levels ranged from 0.6 to 14.4 mg/cigarette. ⋯ Virginia tobaccos which show a low nitrate content are low in NNN but rather high NNK concentrations were found. The results from these pure tobacco types demonstrate that the nitrate content of the tobacco has a great influence on the TSNA level. However, Virginia tobaccos show higher NNK concentrations than expected according to their low nitrate content.