Etemadi A, Poustchi H, Calafat AM, et al. - Researchers sought to gather data concerning human exposure to carcinogens and other toxicants related to opiate use, alone or in combination with tobacco. From the Golestan Cohort Study in Northeast Iran, they assessed 28 participants who were never users of either opiates or tobacco, 33 participants who were exclusive cigarette smokers, 23 participants who were exclusive users of smoked opiates, and 30 participants who were opiate users and also smoked cigarettes (dual users; 21 smoked opiates and 9 ingested them). Urinary concentrations of 39 exposure biomarkers was done; these comprised tobacco alkaloids, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC). They used decomposition to parse out the share of the biomarker concentrations explained by opiate use and nicotine dose. The highest concentrations of all biomarkers was evident in dual users, however, substantially higher concentrations of PAH and VOC biomarkers were noted in exclusive cigarette smokers and exclusive opiate users than never users of either product. The analysis thereby suggests exposure to many toxicants and carcinogens among both cigarette smokers and opiate users (by smoking or ingestion).