What is Spit Tobacco?
Spit tobacco (ST), also known as "smokeless tobacco", is defined as tobacco that is used either orally or through the nasal cavity. Spit tobacco requires no combustion for self-administration as is the case for tobacco used in cigarettes. There are two primary forms of spit tobacco which are generally referred to as "snuff" and "chewing tobacco."[1-4] Snuff is composed of finely ground tobacco which can be either moist or dry. It is most commonly used orally by placing a portion or 'dip' in between the lip and gum and holding it in place for a prolonged period of time. Snuff may also be used by snorting it through the nose. Chewing tobacco usually comes in the form of shredded or loose-leaf tobacco, although it may be found in the form of dried bricks or twisted strands. It is primarily used orally by placing it into the mouth and chewing. As with snuff, chewing tobacco is often held in the mouth for prolonged periods of time. Regardless of its physical form, spit tobacco contains known carcinogens; N-Nitrosamines and Benzopyrene; irritants such as hydrazine, cadmium, formaldehyde and acetaldehyde; nuclear waste such as uranium 235 and polonium 210; and varying concentrations of a highly addictive drug, nicotine.
Health Risks
In a report on the health effects of spit tobacco, the Council on Scientific Affairs of the American Medical Association stated, "pharmacologic and physiologic effects of smokeless tobacco include the gamut of cardiovascular, endocrinologic, neurologic, and psychological effects associated with nicotine."[5] In addition, this report cites a number of studies which document the effects of snuff and chewing tobacco on reproduction, longevity, and oral health. In 1993 the U.S. Surgeon General, Antonia Novello M.D., stated,"Within the next couple of decades the United States may face an epidemic of oral cancer due to the use of smokeless tobacco among teenagers."[6]
The oral effects are the most immediate and visible manifestations of spit tobacco use. These effects include: attrition of tooth structure, staining, halitosis, gingival recession, periodontal disease, leukoplakia and cancer of the mucous membranes. Bowles et al. recently documented that the mean percentage of insoluble particles in ST responsible for mechanical irritation, loss of tooth structure, and loss of periodontal structures is 60% for snuff and 40% for chewing tobacco (Figure 1).[7] Tooth and periodontal structure loss is irreversible.
Percentage Insoluble Particle Content of Tobacco Products
Source: Journal of the American Dental Association, March 1995
Numerous studies have documented the development of leukoplakia or "white patch" on oral mucosa adjacent to the site where the spit tobacco has been held in the mouth. The severity of the epithelial change varies with dose and time. Kaugers et al. concluded that the only significant risk factor for ST-induced oral lesions, specifically ST leukoplakia, was the extent and site of ST exposure.[8] If spit tobacco is discontinued before malignant transformation of the affected cells occurs, the leukoplakia or "snuff user's" patch will repair and disappear. Incidence figures graphed by age for oral and pharyngeal cancer (Figure 2) demonstrate the relatively long latent period associated with the development of oral cancer as evidenced by the sharp rise in incidence after the age of 45 in all groups. Once malignant transformation occurs, the change is irreversible, considered cancerous, and requires treatment. The overall mortality rate from oral cancer (Figure 3) is relatively high, and there is considerable morbidity associated with treatment.
Recurrence and a second primary cancer is common with oral cancer of spit tobacco origin due to field cancerization.[9] Consequently, the five-year survival percentage for oral cancers of spit tobacco origin (37%) is lower than the already low overall survival percentage for oral cancer in general (50%). As noted by the participants of the 1996 National Strategic Planning Conference on Oral and Pharyngeal Cancer, one of the difficulties in mounting a successful campaign against oral cancer is the lack of survivor advocates.
Oral cancer is the most widely known and most easily documented association between prolonged use of spit tobacco and the development of cancer. However, the entire lining of the gut and urinary system is exposed to the carcinogens in spit tobacco. The effect of these carcinogens on cancers of the lining membranes of the stomach, esophagus, and bladder is thought to be similar to those demonstrated in the mouth.
U.S. Oral Cavity and Pharyngeal Cancer Incidence per 100,000
1983-1987
by Age, Race and/or Gender
Source: Cancers of the Oral Cavity and Pharynx: A Statistics Review Monograph 1973-1987,
U.S. Department of Health and Human Services
U.S. Oral Cavity and Pharyngeal Cancer Mortality per 100,000
1983-1987
Source: Cancers of the Oral Cavity and Pharynx: A Statistics Review Monograph 1973-1987,
U.S. Department of Health and Human Services
The addictive property of nicotine in spit tobacco is an additional health concern. Studies indicate that the degree of nicotine dependence among spit tobacco users is comparable or greater than that of smokers. The average nicotine content in one "dip" of snuff is approximately four times that of one cigarette. Although the average nicotine dose per dip is higher than that of cigarettes, the absorption rate is slower, resulting in similar levels of nicotine.[10] Accordingly, withdrawal symptoms suffered by spit tobacco users parallel those of smokers.[11]
Data reported by Hoffmann et al.[12] suggests that the best-selling brands of moist snuff in the United States deliver not only the highest levels of nicotine, but also the highest concentration of tobacco specific N-Nitrosamines (TSNA). A consumer of 10 grams of snuff per day may be exposed to carcinogenic N-Nitrosamines at a level of 1.5 to 2.8 times greater than that of a 20-cigarette per day smoker.[12] During the last decade, a gradual decrease in TSNA has occurred in the two most popular snuff brands which comprise about 90% of the market in the United States. However, one recently introduced brand of spit tobacco has the highest concentration of N-Nitrosamines ever reported in spit tobacco history.[13]
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