Persistent organic pollutants in smokeless tobacco from Uzbekistan, levels patterns and risk assessment

Background Smokeless tobacco (SLT) products, notably nasvay, are widely used in Uzbekistan, yet the extent and implications of pesticide contamination in these products are not well understood. This study provides the first comprehensive evaluation of persistent organic pollutants (POPs) in SLT across six key regions of Uzbekistan, focusing on both their presence and associated health risks. Methods Twenty-five SLT samples were systematically collected from Tashkent City, Tashkent Region, Jizzakh, Samarkand, Fergana, and Kashkadarya. Using gas chromatography–mass spectrometry, concentrations of organochlorine pesticides—including hexachlorocyclohexane isomers, endosulfan, DDT, hexachlorobenzene, toxaphene, dieldrin, and mirex—were quantified. Results The study documented marked regional variation in SLT contamination, with Jizzakh and Tashkent displaying notably high levels of endosulfan (endosulfan-1 up to 17.92 ng/g, endosulfan-2 up to 27.34 ng/g), while Fergana showed lower overall contamination. The persistence of legacy pesticides such as DDT and hexachlorobenzene underscores ongoing environmental contamination and inadequate regulatory enforcement. Human exposure estimates indicated that hazard quotients and cumulative hazard indices for individual POPs remained below international safety thresholds under modeled scenarios; nonetheless, the frequent detection of highly toxic and banned substances raises valid public health concerns. Conclusion These results highlight an urgent need for the development and enforcement of systematic safety standards, routine surveillance, and targeted toxicological risk assessments for SLT products. Regulatory intervention is essential to mitigate chronic health risks among SLT users and reduce the long-term burden of pesticide-related diseases in Uzbekistan.