Arsenic in African Waters: A Review

Abstract

The review of studies on arsenic in African waters shows that arsenic can be found in high concentrations in both surface water and groundwater. Arsenic concentrations in African groundwater range between 0.02 and 1760 μg L−1, whilst the level of arsenic in surface water is ranged up to 10,000 μg L−1. This high level of arsenic in surface water is related to mining operations, agricultural drains, local sediments, disposal, and incineration of municipal and industrial wastes. However, mining activities remain the main source of surface water pollution. They have thereby a strong impact on the concentration of arsenic in the environment. As for groundwater, high levels of arsenic occur in natural conditions. It is due to the presence of iron oxides; sulphide minerals such as pyrite, arsenopyrite, and chalcopyrite; volcanic rocks; and geothermal waters. Few studies in Africa make the link between human health problems and high levels of arsenic in water. Only two articles were found dealing with arsenic remediation. This shows that arsenic, which constitutes a major public health issue in the world, has less interest in Africa although high concentrations of arsenic have been found in both surface water and groundwater in some African countries. Most of the studies carried out on arsenic issues in Africa are dedicated to the characterization and the quantification of the pollution, but studies on the risk to human health and treatment systems are limited. The arsenic issue in Africa needs special attention in order to avoid the problems experienced in some areas mainly in Asia.