3-Dimensional Surface Magnetic Susceptibility Distributions with Depth to Investigate Anthropogenic Pollutants Boundary in Abuja Metropolis

Changes in the magnetic susceptibility of topsoil, especially in urban areas, are greatly affected by the deposition of anthropogenic metallic dust arising from industrial activities, the burning of fossil fuels, car wear, and tyre abrasion. In this study, magnetic susceptibility measurements were carried out in vertical soil profiles of 30.0 cm depth from the surface at 10.0 cm intervals in about 431 locations within the Abuja metropolis with a view to investigate the penetration ability of magnetic pollutants in the ground. From the obtained data, 3-D surface contour maps were plotted for different depths. The results show a magnetic susceptibility decrease from the surface down the ground to the depth of 30.0cm; most of the recorded susceptibilities were of an anthropogenic origin rather than pedogenic activities. This indicates that the anthropogenic dust depositions are mostly a surface phenomenon and may therefore not pose a risk to groundwater aquifers and near surface wells.