Environmental Impact of Artisanal Gold Mining on Soils in Saigbe and Environs, Part of Minna Sheet 164, North-Central Nigeria

Abstract

The environmental geochemistry of soils from Saigbe and environs, Minna, North-central Nigeria was studied with the aim of assessing the impacts of artisanal gold mining activity in Saigbe and environs. Geological fieldwork carried out in the area revealed that the underlying lithologies include schist, granite and amphibolite. A geochemical soil survey was also carried out and a total number of twenty (20) soil samples were systematically collected from both mined and unmined sites within the study area, of which eight (8) representative samples were geochemically analysed. Elemental concentrations (major and trace elements) in the soil samples were determined using X-Ray Fluorescence (XRF) technique. The physical impacts observed during fieldwork include loss of vegetation, land degradation, water pollution and abandoned pits. The average concentrations of the elements determined were compared with the published upper crustal abundance of the individual elements and subsequently their enrichment ratios were computed. Elements such as Ag, Au and Hg show high enrichment with 1.81 ppm, 0.03 ppm and 0.11 ppm concentrations respectively. The result from accumulation index (Igeo) also shows possible Hg contamination. This potentially toxic element can cause serious damage to the skin, nervous and digestive systems in man through direct or indirect consumption.