Assessment of heavy metal pollution in a columbite/tantalite mining site in Edege-Mbeki, North Central Nigeria

Abstract

The release of pollutants due to mining activities, especially tailings, has negative consequences on soil and affects agricultural productivity. This study details the assessment of metals (Ni, Mn, Pb, Cd and Fe), physicochemical parameters of the soil and how they affect metal bioavailability and biotoxicity. Metal concentrations were determined using Atomic Absorption Spectrophotometer (AA-6800 Shimadzu). The results of the analysis show that the mean pH varied from a minimum of 7.12±0.36 to a maximum of 7.60±0.28 across all the study area and sampling points. The percent organic matter had an average minimum value of 0.13±0.08% and a maximum value of 0.82±0.32% in the study area. The heavy metal analysis result shows that concentrations in all the soil and sediments of the study area were all below the maximum permissible limit. Mean concentrations of Ni, Mn, Cd, Pb and Fe had minimum values of 1.45±0.56, 43.3±0.43, 1.11±0.22, 5.50±0.28 and 522±0.88 mg/kg respectively, and the mean maximum concentrations had values of 11.70±0.90, 200±0.17, 20.7±0.11, 31.0±0.78 and 2716±0.83 mg/kg respectively. The findings show no metal contamination. However, the enrichment factor and contamination factor revealed that the presence of Ni, Mn, Cd and Cd in soil samples of the study area may be due to anthropogenic activities of mining.

Keywords: Heavy metals, Edge-Mbeki, Physiochemical, Contamination