Geochemical Characteristics of Soils and Plants around Mining Sites in Parts of Ilorin Sheet 223

Abstract

Mining is an important process that fosters economic growth by extracting valuable minerals from the earth's surface. However, this industry also poses significant environmental challenges, such as soil and water pollution and habitat destruction. This study aims to assess the impact of mining activities on heavy metal concentrations in soil and Neem plant leaves in two mining sites. The research utilized atomic absorption spectrometry (AAS) to analyze the heavy metal content in soil and plant samples. The obtained data were used to calculate various contamination indices, including the contamination factor index (CF), degree of contamination (Cd), modified degree of contamination (mCd), pollution load index (PLI), and accumulation index (Igeo) for soil samples. Additionally, the bioaccumulation coefficient (BAC) was calculated for Neem plant leaves. The X-ray diffraction (XRD) analysis was conducted to identify the mineral composition of the rock samples collected from the study area. The average values for Cu, Pb, Zn, Fe, Mn, Ni, and Co in test soil sites are higher than those in control sites, with significant differences (p-value <0.05) for Cu, Zn, Fe, and Co, indicating contamination due to mining. Similarly, for Neem plant leaves, the average concentrations of Cu, Pb, Zn, and Co are higher in test sites than in control sites, indicating bioaccumulation from the mining activities. However, the calculated contamination indices suggest that the level of contamination in the study area is relatively low. The XRD analysis revealed distinct peaks corresponding to various minerals, including Orthoclase, Albite, Muscovite, Quartz, Dolomite, Anorthite, and Illite. The mineral proportions were assessed, with quartz being dominant in the igneous rocks and dolomite in the marble samples.