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

Abstract 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 µg/g) and Ni (0.81 ± 1.48 µg/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.