ABSTRACT
ABSTRACT: An increasing need for food security together with the exploitation of groundwater resources are happening in Africa. Increased food production inevitably leads to an increase in the application of pesticides. This paper reviews the main sources and processes leading to groundwater contamination from pesticides, the status of groundwater contamination from pesticides in Africa and in particular South Africa. It then also discusses possible mitigation measures for groundwater protection from pesticide contamination. Pesticides in African groundwaters mainly originate from high-income crop plantations (like sugarcane, subtropical fruit orchards, vegetables) and insect disease vectors control in houses. A thorough understanding of the mechanisms of groundwater contamination from pesticides is based on the knowledge of vadose zone and hydrogeological properties, as well as the properties of specific pesticides. Although recent studies indicated that groundwater could be exposed to more risks than surface waters, measurements of pesticides in African surface waters are much more common than in groundwater. A lack of monitoring data as well as education and training in pesticide management is a major concern in Africa. It is not only pesticides currently in use that could have an impact on groundwater but also persistent pesticides that have been banned as well as obsolete stockpiled pesticides. A wide range of mitigation measures can be applied to limit groundwater contamination from pesticides namely improved on-farm management, integrated pest management, biological control, bioremediation and phytoremediation, vegetative buffer strips as well as water purification. The implementation of these procedures depends on ecological, economic and social aspects, as well as possible adverse side-effects in specific countries.
