Tobacco-specific nitrosamines in European and USA cigarettes.

More than 170 types of commercial cigarettes from several European countries and the USA were analyzed for tobacco-specific nitrosamines (TSNA) in tobacco and mainstream smoke as well as for nitrate in tobacco. The cigarettes included filter and nonfilter cigarettes with different tar and nicotine yields. The observed range for N'-nitrosonornicotine (NNN) was from 4 to 1353 ng/cigarette in mainstream smoke and from 45 to 12454 ng/cigarette in tobacco. For 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) the values were between not detected (less than 4 ng/cigarette) and 1749 ng/cigarette in mainstream smoke and between not detected (less than 50 ng/cigarette) and 10745 ng/cigarette in tobacco. Nitrate levels ranged from 0.6 to 19.4 mg/cigarette. The TSNA levels for the cigarettes from the different countries investigated were in a similar range with the exception of few individual brands. The results demonstrated that there is no correlation between TSNA and tar deliveries in mainstream smoke. The TSNA deliveries in mainstream smoke depend on the amount or preformed TSNA in the actual tobacco composition, which is influenced by the nitrate level of the tobacco and the tobacco type. According to these results the tar delivery, although crucial, is not a sufficient index for the biological activity and the carcinogenic potential of cigarette smoke. Reduction of TSNA exposure can be achieved by selecting tobaccos with low levels of preformed TSNA in tobacco, which means a low nitrate content and reduction of the amount of Burley tobaccos and stems in blended cigarettes.