Etemadi A, Poustchi H, Calafat AM, et al. - In order to generate data on human exposure to carcinogens and toxicants associated with opiate use, alone or combined with tobacco, researchers performed this inquiry analyzing male participants of the Golestan Cohort Study in Northeast Iran. They analyzed never users of either opiates or tobacco (n = 28), exclusive cigarette smokers (n = 33), exclusive users of smoked opiates (n = 23), and opiate users who also smoked cigarettes (n = 30) (dual users; 21 smoked opiates and 9 ingested them). They found the highest levels of all biomarkers in dual users and substantially higher levels of polycyclic aromatic hydrocarbon (PAH) and volatile organic compound biomarkers in exclusive cigarette smokers and exclusive opiate users vs never users. The contribution of opiate use to a larger part of the PAH levels than nicotine dose was revealed in the decomposition analysis, as well as they found the sum of 2- and 3-hydroxyphenanthrene resulted almost completely from opiate use. Overall, exposure to many toxicants and carcinogens was evident in both cigarette smokers and opiate users (by smoking or ingestion).