keywords: Geoaccumulation, Geochemistry, Geological mapping, Heavy metals, Quarrying, Land degradation,
This research was conceptualized to determine the potentially toxic elements concentrations of topsoil due to quarrying activities around Kampani Kirya and environs, near Zungeru North-Central Nigeria. Geological mapping was conducted on a scale of 1:25,000 to determine the disposition and distribution of different rock types in the area. Physical examination of impacts of quarrying on land was done. Heavy metals ( Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, V, Zr, Ba, Sr, Rb and Fe) were analysed in soil samples using X-Ray Fluorescence (XRF). Computation of contamination factor (Cf), Index of geoaccumulatuion (Igeo), enrichment factor (EF) were performed on concentration values of potentially toxic heavy metals to determine the extent of pollution caused by quarrying activities in the topsoil of farming and quarrying areas. The concentration values of heavy metals in soils were also compared with world average background values of heavy metals. Results showed evidence of physical impacts of the quarrying on land through land degradation and loss of top soil, dust and noise pollution. Others include destruction of vegetation cover crops rock textures and structures. The calculated contamination factors indicated that Co and Cr exhibited moderate to considerable contamination. Other heavy potentially toxic elements showed low or negligible contamination levels. However, the modified contamination factor showed that all the elements in the study area showed nil to very low degree of contamination. A considerable percentage of the samples returned Igeo class of 0 which is interpreted to be that these elements have not polluted the environment. Only chromium element exhibited Igeo classes of 1 and 2 which represents slightly to moderately polluted. It can be concluded that potentially toxic elements originate from the mining activities as indicated by contamination indices of the measured parameters. The geochemistry of rocks reflected traces of heavy metals within the mine vicinity. This study, however, allayed the fear of possible heavy metal pollution in the sediment of the study area, but there is the need for continuous monitoring of both sediment and water quality to match the potential threat from increased anthropogenic sources especially in the face of persistent mining activities in the area.