Receptor modeling, ecological risks, and human health impacts of mercury in some Ghanaian topsoils due to mining and commercial activities

Abstract

Globally, elevated environmental mercury levels have been linked to artisanal and small-scale gold mining; however, investigations into mining communities often overlook other potential sources and their contributions to soil mercury accumulation. This study explored the positive matrix factorization (PMF) receptor model to identify other possible sources of mercury contamination in two major mining communities (Kenyasi and Obuasi) and a commercial city (Sunyani) in Ghana. The mercury concentrations across the three study areas showed no significant differences (p = 0.257 at the 95% confidence level). The PMF model identified mining as the major contributor to mercury accumulation in Obuasi and Kenyasi, with other activities, such as farming, also contributing substantially. The generation and burning of hazardous waste in the Sunyani municipality due to increased commercial activities have contributed significantly to mercury contamination. Although the hazard quotient indicated no adverse health effects in the study areas (hazard quotient < 1), the pollution and ecological risk indices showed that Obuasi was significantly enriched with mercury, with considerable levels found in Kenyasi and Sunyani. The results from this study will serve as a good database for environmental studies on mercury particularly in Kenyasi and Sunyani, where there has not been any extensive research on mercury contamination.