Nicotine Exposure and Cancer Risk Potential From Smokeless Tobacco (Nasvay) in Uzbekistan: A Cross-Sectional Product and Comparative Analysis
Jasur Juraev, Zhaoqing Lyu, Menglin Fan, Shuxrat Shukurov, Rustam Yuldashev, Azamjon Toshpulatov, Anvarjon Rakhimov, Sherzad Tuychiev, Tayzar Tun, Jamolkhon Kayumov, Odiljon Mirzamukhamedov, Shomurod Rasulov, Kouji HaradaBACKGROUND
Smokeless tobacco use remains widespread in Central Asia, particularly in the form of nasvay in Uzbekistan. Despite its established association with oral and gastrointestinal cancers, quantitative data on nicotine exposure and potential health risks are limited. This study aimed to assess regional variability in nicotine concentrations of nasvay products and to estimate exposure levels relevant to cancer risk.
METHODS
A cross-sectional product analysis was conducted using 25 nasvay samples collected from six regions of Uzbekistan. Nicotine concentrations were measured using gas chromatography–mass spectrometry (GC–MS). Comparative data for cigarettes sold in China were obtained from published laboratory studies. Estimated daily intake (EDI) and hazard quotient (HQ) were calculated under multiple exposure scenarios based on frequency of use (5 and 10 times/day) and absorption rates (60% and 100%), assuming a 60 kg adult body weight.
RESULTS
Nicotine concentrations in nasvay ranged from 2.07 to 15.66 mg/g, substantially higher than in cigarettes (0.8 mg/g). Tashkent city showed significantly elevated nicotine levels compared with cigarettes (p = 0.032; r = 0.78). Under moderate use (5 times/day), EDI ranged from 0.160 to 3.132 mg/kg/day (60% absorption), with HQ values of 200–3915. Under heavy use (10 times/day), HQ values increased markedly, reaching 400–7830 (60%) and up to 13,050 under maximum exposure assumptions. All scenarios exceeded the safety threshold (HQ > 1) by several orders of magnitude.
CONCLUSION
Nasvay products in Uzbekistan deliver high and highly variable nicotine doses, resulting in substantial exposure and elevated potential health risks. Given the established link between smokeless tobacco use and cancer, these findings highlight an urgent need for regulatory oversight, standardized product monitoring, and targeted cancer prevention strategies in Central Asia.