Carcinogenic and non-carcinogenic health risk assessment of heavy metals exposure from Shanono and Bagwai artisanal gold mines, Kano state, Nigeria

Abstract

This work was aimed at estimating the carcinogenic and non-carcinogenic health risks due to heavy metals on children and adults living in the vicinity of Shanono and Bagwai gold mining environs, Kano state, Nigeria. Flame atomic absorption spectrophotometry was used to obtain the concentrations of the heavy metals Zn, Cu, Cd, Cr, Pb, As, Cr, Mn, Fe and Ni in (40) soils, (8) drinking water and (8) edible plant samples from artisanal gold mining villages within Shanono and Bagwai environs. The obtained concentrations were used to estimate the non-cancer and cancer risks due to exposure from these metals using models provided by the United State Environmental protection Agency for the population ages. The overall hazard index was found to be 0.125 for children and 0.810 for adults and was largely contributed by Cr, As and Co. The overall total excess lifetime cancer risk was majorly contributed by Cr and As and was estimated as 5.77E−06 for children and 7.07E−06 for adults. The overall hazard index and Excess lifetime cancer risks were below the USEPA threshold limit for non-carcinogenic and carcinogenic risks respectively. Therefore, the exposed population ages are unlikely to experience any adverse carcinogenic or non-carcinogenic risks. Keywords: Kano, Nigeria, Heavy metals, Hazard index, Cancer risk, Non-cancer risk