Uptake and metabolism of carcinogenic levels of tobacco-specific nitrosamines by Sudanese snuff dippers

It was recently reported that toombak, a type of snuff used in the Sudan, contained unusually high levels of tobacco-specific nitrosamines. To estimate the internal dose of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) received by individuals who use this type of tobacco, urine from a group of users was analyzed for 2 metabolites of NNK, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its O-glucuronide, NNAL-Gluc. NNK is a strong lung carcinogen believed to contribute to human lung cancer. NNAL is also a lung carcinogen. NNAL and NNAL-Gluc were analyzed by gas chromatography with a nitrosamine selective detector. The average levels detected were 0.39 +/- 0.14 (SD) nmol/ml urine (n = 7) and 0.88 +/- 0.50 nmol/ml urine (n = 7), respectively. In a 24-h period, these individuals would excrete from 0.12 to 0.44 mg of these two metabolites (expressed per mg NNAL). Therefore, assuming chronic toombak use, the minimum daily dose of NNK to which these users were exposed was 0.12-0.44 mg. This is the highest documented uptake of a nonoccupational carcinogen. Two diastereomers of NNAL-Gluc were present in all urine samples analyzed. Previously, these two diastereomers were identified in the urine of an NNK-treated patas monkey but only one was detected in the urine of NNK-treated rats. The level of the 4-hydroxy-1-(3-pyridyl)-1-butanone releasing hemoglobin adduct was also quantified in these individuals. This adduct is believed to be a measure of NNK activation. The levels ranged from 68 to 323 fmol/g hemoglobin [mean, 148 +/- 104 (SD)]. The wide range of adduct levels which were observed suggests that despite similar levels of NNK exposure, there are significant differences in the ability of individuals in this population to activate NNK, as well as potential differences in their cancer risk.

Carcinogenic tobacco-specific nitrosamines are present at unusually high levels in the saliva of oral snuff users in Sudan

Exposure to tobacco-specific nitrosamines (TSNA) has been measured in the saliva of 12 users of Sudanese oral snuff (toombak). Using GC coupled to thermal energy analysis, levels of N'-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), N'-nitrosoanabasine (NAB) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were measured before, during and after snuff taking. In addition, two TSNA, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and 4-(methylnitrosamino)-4-(3-pyridyl)-1-butanol (iso-NNAL), were detected in the saliva of tobacco chewers for the first time and were confirmed by GC-MS. Nine out of 10 subjects had detectable saliva levels of total TSNA before chewing (0.01-1.0 micrograms/ml) and immediately following chewing (0.1-2.6 micrograms/ml). During dipping, TSNA concentrations reached microgram/ml levels; (range; number of subjects positive) NNN: (0.6-2.1; 12/12), NAT (0.06-0.5; 2/12), NAB (0.05-1.9; 12/12), NNK (0.06-6.7; 11/12), NNAL (0.05-3.3; 11/12) and iso-NNAL (0.07-0.4; 8/12). These saliva TSNA levels, which are 10-100 times the levels previously reported, are consistent with recent observations of unusually high TSNA levels in Sudanese toombak. As several of these TSNA have been shown to be carcinogenic in animals and epidemiological studies have associated human snuff use with tumours of the oral cavity, these findings draw attention to a significant potential public health hazard.

Unusually high levels of carcinogenic tobacco-specific nitrosamines in Sudan snuff (toombak)

The aim of these studies was to determine the levels of carcinogenic tobacco specific nitrosamines (TSNA) in Sudanese oral snuff (toombak) as recent retrospective epidemiological studies suggested an association between the use of toombak and subsequent development of oral cancer. We have analyzed the TSNA levels in 20 samples of Sudanese toombak, of four different quality levels, collected from five different vendors. Using GC coupled with thermal energy analysis, four TSNA were quantified in snuff extracts: N'-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), N'-nitrosoanabasine (NAB) and 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Unusually high levels of these TSNA (mean; range, mg/g snuff, dry wt) were detected; NNN (1.13; 0.50-3.08); NAT (0.08; 0.02-0.29); NAB (0.22; 0.02-2.37); and NNK (2.31; 0.62-7.87). Previously, the highest levels of NNN and NNK reported in any snuff were 0.154 and 0.014 mg/g dry wt respectively. In comparison, the levels in Sudanese toombak were up to 20 and 560 times higher respectively. As the public health implications of these findings are significant, attempts should be made to reduce exposure to TSNA in oral snuff users in Sudan.

Snuff dipping and oral cancer in Sudan: a retrospective study

A retrospective study involving 78 cases of oral carcinoma was conducted to investigate their association with the habit of taking snuff orally known as 'snuff-dipping' and locally termed 'saffa'. It was found that 50 (81%) of the 62 questioned patients used snuff in the form of saffa. It was also found that carcinomatous changes usually developed in the area of the mouth where the snuff was habitually placed. It was concluded that the association between saffa and development of oral carcinoma is likely to be causal.

Actinomycetoma of the mandibular region causing ankylosis

A case of mycetoma of the mandibular region caused by Actinomadura madurae is presented. Diagnostic procedures and rationale for treatment are discussed. In tropical and subtropical areas where mycetoma is endemic it should be included in the differential diagnosis of tumours of the facio-maxillary region.