Determination of Selected Heavy Metals in Soil and Water from Jatau – Garin Gabas Gold Mining Site in Niger State

Abstract

Concentrations of Cd, Fe, Ni, Pb and Zn in soil and water collected within and around local artisanal gold mining sites in Jatau – GarinGabas village of Rafi Local Government Area of Niger State were determined using Atomic Absorption Spectrophotometry (AAS) technique. The mean concentration for Ni was 103.38 and 186.11 mg/kg for the soil samples and between 0.01 and 0.23 mg/l for the water samples; Fe, between 273.35 and 476.71 mg/kg for the soil samples, and 0.28 and 2.87 mg/l for the water samples; Zn between 49.90 and 117.47 mg/kg for the soil samples, and 1.05 and 2.08 mg/l for the water samples; Pb varied widely from 19.0 and 28.39 mg/kg for the soil samples, while for the water samples it ranged between 0.17 and 0.58 mg/l; Concentration of Cd in soil samples ranged between 0.22and 0.85mg/kg and 0.001 and 0.003 mg/l for the water samples. The order of occurrence in the soil samples were Fe > Ni > Zn >Pb> Cd for the soil samples, and Fe > Zn >Pb> Ni > Cd for the water samples. All heavy metals tested in the soil samples except Pb were found to have exceeded the permissible limits set by the World Health Organisation. Similarly, Pb and Fe in the water samples tested exceeded the permissible limits. The study revealed that the water bodies and the soil around the mining site were polluted with tailings from the mines during the process of washing the minerals, and therefore not fit for drinking and agricultural activities respectively. Regular monitoring of mining activities should be carried out from time to time to ensure a safe environment for man and other living organisms in the area.