Evaluation de la Qualité de l’Eau du lac Azili et Risques Sanitaires Associés à sa Consommation dans le Quatrième Arrondissement de la Commune de Zagnanado (Sud Bénin)

The objective of this study is to evaluate the quality of the water of Lake Azili as well as the health risks linked to its consumption in the fourth district of Zagnanado. Field surveys were carried out to understand the degree of hygiene and sanitation on the island of Agonvè and possible sources of pollution in the said lake. The sample size (50) was determined according to the method of Schwartz (2002). As for sampling, six sites were essentially sampled taking into account the places most frequented by the population. The physico-chemical analyzes carried out using the spectrophotometer method and the colorimetric method indicate values that do not comply with Beninese standards for drinking water as well as the NQE standard for surface water, thus indicating poor quality of the water resource. Membrane filtration and seeding by incorporation were used as part of the bacteriological analyses, the results of which revealed a high load of total Coliforms (on average 155.33 CFU/Ml) which were thermotolerant (on average 24 CFU/mL) and Escherichia coli (average 39.66). The waters of Lake Azili are therefore polluted from a physicochemical and bacteriological point of view. Improving hygiene and sanitation conditions on the island of Agonvè is crucial for the good health of the population but also for the preservation of this water resource.