Carcinogenic substances in Soviet tobacco products.

Chemical carcinogens were determined in mainstream smoke from nonfilter cigarettes produced and consumed in the USSR and in nass, a mixture of tobacco, lime, ash and cotton oil. Cigarettes contained high levels of tar (23-25 mg/cigarette) and nicotine (1.5-1.9 mg/cigarette) and, generally, a high content of polycyclic aromatic hydrocarbons, which are major epithelial carcinogens, N-nitrosamines, which are organ-specific carcinogens, and some carcinogenic metals, such as arsenic and chromium. Nass contained the tobacco-specific N-nitroso compounds, N'-nitrosonornicotine, N'-nitrosoanatabine, N'-nitrosoanabasine and 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone, as well as volatile N-nitrosamines, but at levels lower than in other types of chewing tobacco and snuff. The low levels in nass are due to the short ageing process used, in contrast to commercially produced chewing tobacco and fine-cut snuff, which are highly processed products requiring long ageing and fermentation.