Soil Pollution by Chromium in Sub-Saharan Africa

Abstract

This chapter explores the physicochemical characteristics of chromium (Cr) and how they exert pollution in soils of sub-Saharan Africa. The metal is sourced mainly from ferrochrome- and chromite-based ores found in mafic and ultramafic rocks. The hexavalent form, Cr (VI), which is more soluble and bioavailable is more toxic compared to the trivalent form, Cr (III) that is immobile. Industrial activities including leather tanning that uses chromium basic sulfate, mining of ferrochrome and smelting activities, production of steel and manufacture, and use of agrochemicals introduce Cr to soils of SSA region. The unsystematic management of solid waste and wastewater containing the metal is also affiliated to its soil pollution. Evidence of Cr poisoning in soils of SSA region was reported in many studies, which is an environmental concern that requires corrective measures.