Potentially Toxic Elements in Local Cigarettes and Marijuana Leaves of Bauchi State, Nigeria: Public Health and Environmental Implications

Abstract

Exposure to potentially toxic elements (PTEs) in commonly used substances remains a serious public health concern, especially in low-regulation environments. This study assessed and compared the concentrations of five PTEs, cadmium (Cd), lead (Pb), zinc (Zn), iron (Fe), and copper (Cu), in marijuana and Aspen-brand cigarettes consumed in Bauchi, Nigeria. Using atomic absorption spectrophotometry (AAS), we analyzed PTE content in both substances after acid digestion and proper calibration. Cigarettes showed higher levels of all tested metals. Cd (3.12 μg/g) and Pb (0.88 μg/g) in cigarettes exceeded WHO limits, while marijuana contained lower levels of Cd (0.645 μg/g) and Pb (0.11 μg/g), with only Cd approaching the level that poses environmental and public health concern. Zn (71.2 μg/g), Cu (64.0 μg/g), and Fe (19.2 μg/g) were also significantly higher in cigarettes (p < 0.01). The high levels of Cd and Pb in cigarettes indicate that smokers are more exposed to harmful PTEs through inhalation than marijuana users, which points to a greater health risk from cigarette use. These findings call for stronger policies and regulations that ensure cleaner agricultural practices and industrial accountability to minimize exposure to harmful PTEs and protect community health in Bauchi.