Analysis of the distribution of heavy metals in the soils of Bagega mining area Zamfara state, Nigeria

Abstract

Uncontrolled exploitation and degradation in the environment over the past few decades as the result of urbanization and poverty has caused a serious damage to lives and properties. The study analysed the spatial distribution of heavy metal (Fe, Cu and Zn) in Bagega, Zamfara state. Three mapping units were identified and samples were collected from the top soil (0-15cm) horizon using stratified random sampling techniques. These include the Mining Processing Environment (MPE), Residential exterior (RE) and Surrounding Farmlands (SF). In each mapping units, twelve (12) samples were collected randomly. Coordinates of all samples points were recorded using GPS. The soil sample were analyse for heavy metals using Atomic Absorption Spectrophotometer (AAS) and the result were recorded in Microsoft excel and later transformed into GIS environment in the Arc GIS 10.1 version. Krigging model was used for mapping the spatial distribution of the heavy metals in the study area. The result shows that there are more concentrations of heavy metals (Fe and Cu) in the Residential exterior (RE) and streams sites. The level of heavy metal in the soils of the area were below the acceptable toxic level of and this can be attributed to the number of years quarry activities in the study area have been in operation. The study concluded that Fe and Zn are more concentrated to the mining and river sites areas, while Cu is highly concentrated at the farmlands areas. The study recommends for continuous monitoring and mining should be avoided especially closer to the residential areas.

Keywords: Spatial distribution, Mapping, Heavy metals, Bagega