Abstract:
OBJECTIVE: Oral tobacco products contain nicotine and
carcinogenic tobacco-specific N-nitrosamines (TSNAs)
that can be absorbed through the oral mucosa. The aim
of this study was to determine typical pH ranges and
concentrations of total nicotine, unionised nicotine (the
most readily absorbed form) and five TSNAs in selected
oral tobacco products distributed globally.
METHODS: A total of 53 oral tobacco products from 5
World Health Organisation (WHO) regions were analysed
for total nicotine and TSNAs, including 4-(methylnitrosamino)-
1-(3-pyridyl)-1-butanol (NNAL), using gas
chromatography or liquid chromatography with mass
spectrometric detection. Unionised nicotine concentrations
were calculated using product pH and total nicotine
concentrations. Fourier transform infrared spectroscopy
was used to help categorise or characterise some products.
RESULTS: Total nicotine content varied from 0.16 to
34.1 mg/g product, whereas, the calculated unionised
nicotine ranged from 0.05 to 31.0 mg/g product; a 620-fold
range of variation. Products ranged from pH 5.2 to 10.1,
which translates to 0.2% to 99.1% of nicotine being in the
unionised form. Some products have very high pH and
correspondingly high unionised nicotine (eg, gul powder,
chimo´, toombak) and/or high TSNA (eg, toombak, zarda,
khaini) concentrations. The concentrations of TSNAs
spanned five orders of magnitude with concentrations of
4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)
ranging from 4.5 to 516 000 ng/g product.
CONCLUSIONS: These data have important implications for
risk assessment because they show that very different
exposure risks may be posed through the use of these
chemically diverse oral tobacco products. Because of the
wide chemical variation, oral tobacco products should
not be categorised together when considering the public
health implications of their use.
