Environmental Geochemical Assessment of River Gora Sediments in Minna, North-Central Nigeria

Abstract

This paper is concerned with the assessment of pollution index level of trace elements in the sediments from River Gora using geochemical approach and also to investigate the environmental impact of artisanal mining activities in the area. The study area lies between latitude 9⁰33^’N and 9⁰34^’N and longitude 6⁰34^’E and 6⁰35^’E in Minna area of North-central Nigeria. Accessibility to the sampling locations is via Chanchaga-Tegina road, minor roads, footpaths and the river channel. Major oxide and trace elemental compositions of the samples were analyzed using X-Ray Fluorescence spectrometry Epsilon-5 Panalytical model. The results were subjected to statistical treatment and interpretation. The samples have calculated average chemical alteration index of 76.44 indicative of complete chemical weathering of feldspar and mica in the country rocks of the area. Sb, Au, Mo, Cu, Zr and V are enriched in the study area, while Nb, Co, Zn, Sr, Pb, As, Rb, Cr, Ni, and Ba are depleted in comparison to their upper continental crustal concentrations. The artisanal mining activities in the study area do not pose any environmental health concern because the concentrations of heavy metals such As, Pb, V, Rb, Sr, Cu, Zn, Cr, Co are within safe environmental health concentrations. However, the values for Sb and In are source of extreme pollution risk in the study area; thus a comprehensive study to mitigate their environmental health risks was recommended.

Keywords: Environmental Geochemistry, Pollution Index, Health Risk, River Gora, Minna