Bioremediation of Heavy Metal Contaminated Soils in Sub Saharan Africa: Implications for Food Safety and Public Health Nutrition

Most Sub-Saharan African nations are faced with increasing build-up coupled with persistence of compounds which are toxic in their soil. These persistent toxic materials constitute a significant danger to the environment. Heavy metals are major contaminants consistently found in sediments, air, water, and soil and has bio-accumulative potential in the food chain. They often enter the environment as a consequence of industrial processes such as electroplating, extraction and refining of mineral ores etc. Heavy metals accumulate in some plants, leading to biomagnification in humans when such plants are consumed, creating a serious threat to food safety and public health. At minute levels, some heavy metals are co-factors partaking in the production of enzymes in the body. Occurrence of these metals above threshold limits can be responsible for their behaving in a deleterious manner in which they displace other metal ions, block specific functional groups, or modify the active configuration of some molecules needed for biological functions The use of technologies such as excavation, soil washing, incineration, landfilling and soil flushing in treating soils contaminated with heavy metals is not cost effective and also not environmentally friendly. Bioremediation which is the use of microorganisms facilitates the breakdown of environmental contaminants like organic wastes and heavy metals to an innocuous state under controlled conditions, Various microorganisms have been used in attenuating the harmful effects of heavy metals in the environment and the process have been observed to be an eco-friendly and cost-effective substitute to the conventional treatment approaches and it enhances both the soil quality and its usage, especially in Sub-Saharan African nations. This review is consequently focusing on the impact of microorganisms in bioremediation.