Analysis of Health Risk Factors in the Vegetable Production Chain in the City of N'Djamena-Chad

Abstract

Several market gardeners have settled in the city and supply urban markets with fresh vegetables throughout the year. Despite their nutritional importance, market gardening products may carry health risks. The objective of this study is to identify and analyse the potential risk factors that could lead to the appearance of microbiological and physicochemical hazards in the production chain of fresh vegetables from these market gardening operations. The work was carried out in 5 permanent market gardening sites in the city of N'Djamena (Chad, Africa) and involved 96 market gardeners surveyed. Data related to production methods were collected. Standard methods were used to carry out microbiological analysis tests on 15 samples of vegetables and fruits taken from 3 sites.The results of the survey show that urban market gardening in N'Djamena is dominated by two plant species: lettuce (Lactuca sativa) and rocket (Eruca sativa). It is geared towards the production of leafy vegetables. The health risks associated with the conditions of production are numerous and real: the proximity of roads, the use of dirty water for irrigation, the overdose of chemical fertilizers (urea) and pesticides, and finally the unhygienic harvesting and transport. The high-water content of fresh vegetables and the lack of processes for the elimination of pathogenic microorganisms also do not guarantee the sanitary quality of the vegetables produced and can thus increase the risk of foodborne infections. The results of the microbiological evaluation showed the presence of germs pathogens including Escherichia coli, Staphylococcus aureus, Aeromonas spp. and Salmonella sp. in vegetable and fruit. Therefore, the best strategy to obtain a healthy product is to educate producers on good agricultural practices including reasoned fertilization, clean water, treated wastewater, approved pesticides.