Global surveillance of oral tobacco products : total nicotine, unionised nicotine and tobacco-specific N-nitrosamines

摘要

OBJECTIVE: Oral tobacco products contain nicotine andcarcinogenic tobacco-specific N-nitrosamines (TSNAs)that can be absorbed through the oral mucosa. The aimof this study was to determine typical pH ranges andconcentrations of total nicotine, unionised nicotine (themost readily absorbed form) and five TSNAs in selectedoral tobacco products distributed globally.METHODS: A total of 53 oral tobacco products from 5World Health Organisation (WHO) regions were analysedfor total nicotine and TSNAs, including 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), using gaschromatography or liquid chromatography with massspectrometric detection. Unionised nicotine concentrationswere calculated using product pH and total nicotineconcentrations. Fourier transform infrared spectroscopywas used to help categorise or characterise some products.RESULTS: Total nicotine content varied from 0.16 to34.1 mg/g product, whereas, the calculated unionisednicotine ranged from 0.05 to 31.0 mg/g product; a 620-foldrange of variation. Products ranged from pH 5.2 to 10.1,which translates to 0.2% to 99.1% of nicotine being in theunionised form. Some products have very high pH andcorrespondingly high unionised nicotine (eg, gul powder,chimo´, toombak) and/or high TSNA (eg, toombak, zarda,khaini) concentrations. The concentrations of TSNAsspanned five orders of magnitude with concentrations of4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)ranging from 4.5 to 516 000 ng/g product.CONCLUSIONS: These data have important implications forrisk assessment because they show that very differentexposure risks may be posed through the use of thesechemically diverse oral tobacco products. Because of thewide chemical variation, oral tobacco products shouldnot be categorised together when considering the publichealth implications of their use.