NNN is the first organic carcinogen isolated from unburned tobacco. It has been found in smoking tobaccos, chewing tobaccos and in snuff in concentrations between 0.3 and 90.0 μg. This appears to be an unusually high concentration for a nitrosamine in an environmental agent. Data are presented which suggest that NNN, and possibly other unknown nitrosamines, are formed during the curing of tobacco and that the nitrate content of tobacco is an important factor in nitrosamine formation. Studies with N' methylanabasine applied to tobacco plants are currently under way to test the idea that nicotine rather than nornicotine is the major precursor of NNN in processed tobacco. in mice, NNN induced adenomas of the lung. Bioassays with rats have shown that NNN is carcinogenic to the esophagus and the nasal cavity. These chemical and biologic data are consistent with the observation that tobacco chewers face an increased risk of cancer of the esophagus. This observation does not, of course, rule out the possibility that other tobacco carcinogens are responsible for the increased cancer risk of tobacco chewers.
|Original language||English (US)|
|Number of pages||14|
|Journal||IARC (International Agency for Research on Cancer) Scientific Publications|
|State||Published - Dec 1 1976|