Microbial and Chemical Contamination of Vegetables in Urban and Peri-Urban Areas of Sub-Sahara Africa

Abstract

Most farmers in urban and peri-urban areas in West Africa have limited land, so practice farming systems targeted at the production of high-value crops used in urban diets, especially exotic vegetables. Moreover, rapid urban population growth and adverse climate change are causing increased demand for food and water, leading to water scarcity in those cities. The intense pressure of increasing food demand in cities pushes small farmers to depend on untreated wastewater, undecomposed manure, and pesticides for their production, which negatively affect the health of the population. This chapter presents an overview of the identification of pathway and levels of vegetables contamination in SSA and the identification of interventions employed to reduce public health risk. The microbiological and chemical assessment of irrigation water, fertiliser and vegetable samples collected from farms and markets in SSA revealed their contamination with pathogenic bacteria above the recommended standard of WHO and ICMSF. They were also contaminated by heavy metal above the safe limits by FAO/WHO and pesticide residues. The treatment of irrigation water, proper composting of manure and appropriate use of pesticides could be complement disinfection of vegetables before consumption to reduce public health risk.