Thesis Abstract

The study examined some physical and chemical characteristics of soils in an unmonitored mining community in southwestern Nigeria. This study aimed at determining if the active (recently mined), abandoned mines, adjacent farmland, and a relatively less-disturbed forest re-growth region in the community exhibit significantly different or similar characteristics. The main hypothesis is that sites of artisanal gold mining activities are characterized by higher concentrations of toxic metals than the farmland and forest sites. A 25 by 25 meters plot was demarcated in each sample area and soil samples were obtained from 0 to 15 cm soil layer (at 5 by 5 m subplot level). Soil samples were analyzed for particle size distribution, pH, organic C, total N, available P, exchangeable Ca2+, Mg2+, K+, and Na+, total acidity, and selected heavy metals (Zn, Hg, Cu, Mn, Cd, Pb, and Fe). The study showed that soils at the active and abandoned mine sites were more of sandy particles, and contained significantly higher concentrations of heavy metals but lesser concentrations of soil nutrients than the farmlands and the relatively undisturbed areas in the study area. The study concluded that artisanal gold mining activities caused severe soil degradation and loss of important soil nutrients in the area. The impact of the mining activities is a major threat to qualitative food security and sustainable livelihoods in the area.

Thesis Overview