The carcinogenic and non-carcinogenic risk assessment of heavy metals from the butts of smoked and non-smoked cigarettes

Cigarettes are known as the most popular tobacco in the world. The aim of this study was to evaluate the concentrations of heavy metals in smoked and non-smoked cigarette butts (CBs) from ten cigarette brands (including five Iranian brands) and human health risk assessment associated with inhalation exposure. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) was used for heavy metals measurement after CBs digestion. The results showed that the highest concentrations of heavy metals in non-smoked and smoked cigarette butts are related to Pb (0.63 +/- 0.21 mu g/g) and Ni (0.81 +/- 1.48 mu g/g), respectively. The concentration of all heavy metals in smoked CBs is significantly higher than in non-smoked. According to the results, Ni and Cd elements in 60% of Iranian brands and 80% of other brands have HI > 1, which indicates a potential non-carcinogenic risk for consumers. Also, the carcinogenic risk of Cr in all brands is higher than 1.00E-4, which indicates the carcinogenic risk of the consumer in case of continuous exposure to cigarette smoke. Heavy metals in CBs can have potential carcinogenic and non-carcinogenic effects on the health of smokers exposed to inhalation. Therefore, continuous monitoring and regulation of the ingredients of domestically produced and imported cigarettes are recommended.