Source Apportionment of Potentially Toxic Elements in Topsoils Across Some Mining-Impacted Communities in Ghana Using the Positive Matrix Factorization Model

Abstract

In this study, we employed the positive matrix factorization receptor model to ascertain whether the prevalence of potentially toxic elements in surface soils of two mining communities in Ghana is exclusive to mining. At the two mining communities (Kenyasi and Obuasi), 49 samples were taken at each location, whereas 90 soil samples were collected from Sunyani, the non-mining community. All the soil samples were screened for elemental concentrations using the Niton XL3t GOLDD+ field portable X-ray fluorescence spectrometer. The positive matrix factorization model was set to three factors in the base model for the analyses, and the receptor model revealed three major contributing factors to the metal pollution in the study areas. Although mining activities contributed to As, Cd, Cu, Ni, and Pb in Kenyasi, a typical mining community, farming activities also contributed significantly to the presence of Zn and Cd in the surface soils. At Obuasi, construction works and geogenic factors were responsible for the enrichment of Cr and Cu in the surface soils, farming activities accounted for the Mn, Pb, and Zn contamination, and As, Cd, and Ni contamination by mining activities. In Sunyani, the non-mining community, the model revealed that the contamination of the soil by Cd, Mn, Ni, and Pb was primarily from multiple sources, such as the mass burning of wastes, farming, and construction works within the municipality. The prevalence of Zn in the municipality was attributed to natural origin since the pollution indices showed low contamination of the metal. This study will serve as a scientific reference for the holistic mitigation of soil heavy metal contamination in the study areas.