Risk Assessment of Toxic Trace Metals and Nicotine Concentrations in Cigarettes Associated with Inhalation Exposure

Abstract

Cigarettes are the most consumed tobacco products associated with severe health conditions like cancer. Regulations such as high taxes, health branded packs and zero-advertisement concepts have been adopted to discourage smoking of cigarettes in many countries. However, cigarette smoking is still a very common practice, irrespective of income and status among citizens. This study assesses the human health risk associated with inhalation exposure of toxic metals and nicotine in eight locally manufactured cigarette brands in Ibadan, Nigeria. Toxic metals [Pb, Cd, Cr and Ni] were determined in the tobacco, unsmoked butt, ash and smoked butt of the cigarette brands along with the nicotine content of the tobacco. Results of the study showed high Pb and Cr levels in order of ash>tobacco>smoked butt>unsmoked butt with no significant difference (p=0.05) between toxic metals in smoked and unsmoked butt of the cigarettes. Nicotine content ranges between 0.782 to 1.158 μg/g. The hazard index of Cd, Cr and Ni were greater than one, which indicates significant non-carcinogenic health risk in all the brands of cigarette. The potential carcinogenic health risk of Cr was higher than the acceptable limits of 1.00E-04 by the USEPA, suggesting that developing cancer during the lifetime of an active smoker through inhalation exposure is significantly high with an estimated likelihood of 341 cases in 10,000. These findings have shown that cigarette smoking poses potential noncarcinogenic and carcinogenic health risks to active smokers. Therefore, more proactive steps are needed to combat or reduce these associated risks.