Heavy metals assessment of farmland soil in Bagega mining community, Zamfara State, Northwestern Nigeria

Abstract

The present study was conducted to examine the level of heavy metals pollution of farmland
soil at Bagega community, Anka Zamfara State as a result of artisanal and illegal mining activities going on in the community. Soil samples were collected from farmland soil at the
depth of 15cm, acid digestion was carried out and the solution was subjected to Atomic Absorption Spectrophotometer model Varian AA240FS for the metal analysis. The level of soil contamination were assessed by Geo-accumulation Index (Igeo) and Pollution Load Index (PLI). The Geo-accumulation studies show that the soil was moderately polluted by Pb (1.21 mg/kg), Fe (0.9 mg/kg), Zn (0.91 mg/kg) and Cu (1.46 mg/kg). The Pollution Load Index result shows that farmland soil was polluted, with PLI value of 2.1. Also, the geochemical distribution of the metals in the soil samples was revealed by sequential extraction procedures which show that 90 % of the metal concentrations were found in the residual fractions. This signified high level of heavy metals contamination of the farmland soil is associated with the anthropogenic activities such as the mining activities going on in the community.