Soil Pollution by Mercury in Sub-Saharan Africa

Abstract

This chapter seeks to understand the sources and chemistry of mercury (Hg), which enable it to exert pollution in soils of Sub-Saharan Africa (SSA) region. Cinnabar was found to be the most common ore from which the heavy metal is found. In soils and as a result of anthropogenic activities, various forms of Hg are found including the particulate, gaseous reactive, and reactive gaseous compounds of the metal. Methyl Hg was found to be the most lethal form in soils due to its high absorption capacity and longer half-life allowing its cycling in different environmental compartments. In SSA, lethal forms of mercury were introduced to soil through Hg-amalgamation during artisanal gold mining. Industrial activities including coal processing and cement making and their associated wastes also polluted the soils of the region. From the growing concern with Hg pollution in soils, it is key to monitor the trends and devise remedial measures.