Geochemical and chemometric analysis of soils from a data scarce river catchment in West Africa

Elemental concentrations beyond stipulated thresholds are a considerable concern for environmental pollution regulators and public health administrators around the globe. Data is, however, lacking in most regions especially developing countries for practical policy decision making and management. In this study, we obtained 49 high-resolution soil cores from three vertical profiles in the Densu River Basin of Ghana and measured the concentrations of major and trace elements (Ca, K, Fe, Ti, Cr, Cu, V, Ni, and Zn). The aim was to examine and provide data on elemental levels to serve as baseline information on mobilization studies for waste management in the basin. Geochemical methods for estimation of metal enrichment and accumulation were employed to determine enrichment and pollution, sources, and mobilization of the metals in the basin. Hierichical cluster and principal components analyses were used to examine metal associations and and the effects soil physicochemical properties on the metals.. The results show spatial variations in the concentrations of the metals within and between soil profiles and were attributed to variability in soil formation processes and the locations where samples were collected in the basin, respectively. Moderate to high enrichment factors (EF) and geo-accumulation (Igeo) index were observed for Vanadium (V) and Chromium (Cr) in all profiles indicating some level of anthropogenic interference leading to pollution. The Pourbaix diagrams, however, showed that the Cr and V abundances may be natural . Vehicular activity and agricultural inputs were identified as some of the most likely source elemental contributions to soil pollution in the basin. Our analysis also showed that most of the metals investigated are of natural geologic origin. The combination of field observations and established methods (geochemical and statistical analyses) aided in extracting beneficial information from the small sample size obtained.