Contamination of water and vegetables in Akaki and Mekanisa areas of Addis Ababa, Ethiopia : microbiological, observational and qualitative study

Abstract

This study was undertaken to assess the extent of pollution of water and contamination of vegetables grown by irrigation with polluted river water. The study was done in the Akaki and Mekanisa areas of Addis Ababa, Ethiopia in 2002. The need to investigate the extent of contamination of vegetables is valid because of repeated occurrence of food-born disease outbreaks in many restaurants in the city of Addis Ababa. This might be partly attributed to the consumption of such contaminated raw fruits and vegetables. The main aim of this study is to determine the microbiological qualities of irrigation water and vegetables, and to assess farmers perception and knowledge about contamination of food and water. Samples of water were collected from different parts of the river in research areas to detect some indicator and pathogenic microorganisms, mainly pathogenic bacteria most prevalent in the area. Different green leafy vegetables were also collected from farm areas and market places for bacteriological laboratory examinations. Both water and food samples were analyzed by standard conventional methods using different bacteriological growing media. Enteropathogens such as Salmonella and Shigella organisms were detected in 22 (73.33%) and 17 56.67%) of the water samples respectively. But, vegetables were positive for Salmonella in 33 (53.2%) and Shigella 24 (38.7%). The general awareness of farmers about water and food contamination is low, and this may lead to poor handling and processing of produces in different levels from production to consumption. Immediate action is needed to control water pollution that attributed to vegetable contamination during irrigation. The outcome of this study is expected to raise the awareness of the responsible bodies concerning pollution of river water and the potential risk of irrigation of fruits and vegetables with such water.