Hoffmann D, Djordjevic M V
American Health Foundation, Valhalla, New York 10595, USA.
Adv Dent Res. 1997 Sep;11(3):322-9. doi: 10.1177/08959374970110030301.
In the United States, smokeless tobacco (ST) is marketed as chewing tobacco and as oral snuff. During the past 15 years, consumption of chewing tobacco has declined by 30.6%, whereas snuff use has significantly increased, namely, by 51.8%. This increase is primarily due to the growing popularity of oral snuff use among teenage and young adolescent males. Chewing of tobacco is associated with an increased risk for oral cancer. Snuff dipping is causally and specifically associated with cancer of the cheek, gum, and pharynx. In laboratory animals, snuff induces cancer of the mouth. Several carcinogens have been identified in ST, the tobacco-specific N-nitrosamine (TSNA), N'-nitrosonornicotine (NNN), and 4(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) being the most important. NNN and NNK are formed from nicotine during curing, aging, and especially during fermentation of tobacco. Oral swabbing of a low concentration of a mixture of NNN plus NNK in water induces oral tumors in rats. The concentration of the strongly carcinogenic TSNA is higher in snuff than in other ST products. According to our analytical studies, the three leading snuff brands in the US (92% of the market) contain far higher concentrations of nicotine, unprotonated nicotine, and TSNA than the less popular brands. Thus, the leading US snuff brands are the strongest inducers of nicotine dependence and also have the highest carcinogenic potential.
在美国，无烟烟草（ST）作为嚼烟和鼻烟进行销售。在过去15年中，嚼烟的消费量下降了30.6%，而鼻烟的使用量则显著增加，即增加了51.8%。这种增加主要是由于青少年男性中使用鼻烟的人数日益增多。嚼烟草会增加患口腔癌的风险。蘸鼻烟与脸颊、牙龈和咽部的癌症有因果关系且有特定关联。在实验动物中，鼻烟会诱发口腔癌。在无烟烟草中已鉴定出几种致癌物，其中烟草特有的N-亚硝胺（TSNA）、N'-亚硝基去甲烟碱（NNN）和4-（甲基亚硝胺基）-1-（3-吡啶基）-1-丁酮（NNK）最为重要。NNN和NNK是在烟草的烘烤、陈化过程中，尤其是在发酵过程中由尼古丁形成的。用低浓度的NNN加NNK的水溶液进行口腔擦拭会诱发大鼠口腔肿瘤。鼻烟中强致癌性TSNA的浓度高于其他无烟烟草产品。根据我们的分析研究，美国三大领先的鼻烟品牌（占市场的92%）所含尼古丁、未质子化尼古丁和TSNA的浓度远高于不太知名的品牌。因此，美国领先的鼻烟品牌是尼古丁依赖的最强诱导剂，且致癌潜力也最高。
