Impact of Artisanal Gold Mining on Heavy Metal Concentrations in Soil and Water in Sabon Eregi Community, Niger State

Abstract

This study was carried out to determine the concentrations of selected heavy metals in soil stream and borehole water in Sabon Eregi mining site of Niger State. Samples were collected from three different points, before, within and after the mining sites and a control sample collected some distance away from the mining site, Physicochemical properties of the water and soil samples were determined using standard methods. Heavy metals analysis of the water and soil samples were carried out using Atomic Absorption Spectrophotometry after acid digestion. The result of the heavy metal concentrations in soil samples in mg/kg were (55.17 – 82.67) for Mn, (BDL - 0.28) for Cd, (25.37 – 53.46) for Zn, (37.67 - 34.19) for Pb and (6.35 – 7.22) for Ni. While heavy metal concentrations in mgdm-3 for stream and borehole water were: (0.10 - 0.35 and 0.42 – 0.48) for Mn, (BDL - 0.01 and BDL - 0.01) for Cd, (0.08 - 0.16 and 0.07 - 0.09) for Zn, (0.16 – 0.29 and 0.06 -0.07) for Pb and (0.01 - 0.03 and BDL - 0.01) for Ni respectively. Generally, the heavy metal concentrations in soil, stream and borehole water in the area were lower than the permissible limits. Thus, Sabon Eregi is still safe for the inhabitants despite the illegal mining activities going on in the area, but continuous monitoring of the area is recommended.