Opiate and Tobacco Use and Exposure to Carcinogens and Toxicants in the Golestan Cohort Study

Background: There is little information on human exposure to carcinogens and other toxicants related to opiate use, alone or in combination with tobacco. Methods: Among male participants of the Golestan Cohort Study in Northeast Iran, we studied 28 never users of either opiates or tobacco, 33 exclusive cigarette smokers, 23 exclusive users of smoked opiates, and 30 opiate users who also smoked cigarettes (dual users; 21 smoked opiates and 9 ingested them). We quantified urinary concentrations of 39 exposure biomarkers, including tobacco alkaloids, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC), and used decomposition to parse out the share of the biomarker concentrations explained by opiate use and nicotine dose. Results: Dual users had the highest concentrations of all biomarkers, but exclusive cigarette smokers and exclusive opiate users had substantially higher concentrations of PAH and VOC biomar- kers than never users of either product. Decomposition analysis showed that opiate use contributed a larger part of the PAH concentrations than nicotine dose, and the sum of 2- and 3-hydroxyphenanthrene (Sigma(2,3)-phe) resulted almost completely from opiate use. Concentrations of most VOC biomarkers were explained by both nicotine dose and opiate use. Two acrylamide metabolites, a 1,3-butadiene metabolite and a dimethylformamide metabolite, were more strongly explained by opiate use. Acrylamide metabolites and Sigma(2,3)-phe were significantly higher in opiate smokers than opiate eaters; other biomarkers did not vary by the route of opiate intake. Conclusions: Both cigarette smokers and opiate users (by smoking or ingestion) were exposed to many toxicants and carcinogens. Impact: This high exposure, particularly among dual opiate and cigarette users, can have a substantial global public health impact.