Qualité physico-chimique et bactériologique des eaux souterraines et risques sanitaires dans quelques quartiers de Yaoundé VII, Cameroun

Abstract

Au Cameroun, l’accès aux systèmes d’alimentation en eau potable en milieu urbain apparaît sélectif. Les populations des quartiers situés en périphérie ont recours aux puits et sources pour assouvir leurs besoins. La présente étude a pour objectif d’évaluer la qualité physico-chimique et bactériologique des eaux souterraines couramment utilisées dans quelques quartiers de l’arrondissement de Yaoundé VII. 24 échantillons d’eaux prélevés dans 6 sources (S1 à S6) et 2 puits (W1 et W2) ont été analysés suivant des méthodes normalisées. Les températures relevées, proches de celle de l’air, révèlent le caractère libre des nappes étudiées. Celles-ci subiraient l’influence directe des eaux d’infiltration. Les stations S1, W1 et W2 présentent des valeurs en nitrates supérieures à 50 mg/l (norme OMS). La consommation de leurs eaux expose la population jeune à la méthémoglobinémie. Contrairement aux recommandations de la norme camerounaise, les indicateurs de pollution fécale et les bactéries du genre Salmonella, ont été isolées dans les eaux analysées. Une analyse en composante principale ainsi qu’un dendrogramme ont permis de classer les points d’échantillonnage, selon l’ordre croissant de pollution organique suivant : {S6}, (S3, S4, S5), (S1, S2), {W1}, {W2}. Cependant, du point de vue pathogénique, S6, S3, S4, S5 sont les plus à craindre.Mots clés : Qualité des eaux, puits, sources, Yaoundé, risques sanitaires.
 English Title: Physico-chemical and bacteriological quality of groundwater and health risks in some districts of Yaoundé VII, CameroonIn Cameroon, access to drinking water supply systems in urban areas appears to be selective. The populations located in the peripheral zone use wells and springs to satisfy their needs. This study aims to assess the physico-chemical and bacteriological quality of the groundwater commonly used in some districts of Yaoundé VII. 24 water samples taken from 6 sources (S1 to S6) and 2 wells (W1 and W2) were analyzed according to standardized methods. The temperatures recorded, close to that of the air, reveal the free nature of the aquifers studied which are directly influenced by the infiltration waters. Samples points S1, W1 and W2 presented concentration of nitrate above 50 mg/l (WHO standard). The consumption of their waters exposes young people to methemoglobinemia. On contrary to the recommendations of the cameroonian standard, the indicators of faecal pollution and bacteria of the genus Salmonella, were isolated in the waters analyzed. A principal component analysis as well as a dendrogram permit to classify the sampling points, according to the following increasing order of organic pollution: {S6}, (S3, S4, S5), (S1, S2), {W1}, {W2}. However, from a pathogenic point of view, S6, S3, S4, S5, are the most to be feared.Keywords: Water quality, Dug wells, spring, Yaoundé, sanitary risks.

Evaluation of the Influence of Some Abiotic Factors on the Microbiological Quality of Groundwater in Soa Sub-division, Cameroon, Africa

“…The permanent presence of these pathogenic bacteria and their high abundance 3.79 log CFU / 100 mL (Shigella) reflects the degree of pollution in these water samples and the high health risk. Similar results have been obtained by Mpakam et al [32] in Bafoussam and Moussina Yaka et al [10], in Yaoundé, where many pathogens such as Escherichia coli, Salmonella, Shigella and many other bacteria witnessing fecal contamination have been observed in the ground waters. These are most likely the toilets in the case of well P4 located upstream of sloping ground and about 2 m from the well.…”

“…Hence, the well P1 is more acidic than the other four wells (P2, P3, P4 and P5). These results are similar to the groundwater of Yaoundé obtained by Moussina Yaka et al [10]. The acidity of the groundwater is believed to be due to the acidic nature of the soils in the region [23].…”

“…Numerous studies have been carried out on the bacteriological quality of groundwater in in Yaoundé [8,9,10,11]. It is to be noted that the study area is located in the peri-urban outskirts of Yaoundé.…”

Spatial evolution of the diversity of macroinvertebrate-Odonate larva population dynamics in relation to the environmental variables of the Niete hydrosystem (South Cameroon)

“…According to Liechti et al (2004)[23] , the thermal variations of lotic ecosystems match those of the air. This temperature range is similar to that obtained by Moussima (2022)[24] for some surface water bodies in the city of Yaoundé as well as by Tchakonté (2016)[25] for the urban and peri-urban waters of Douala. The average water content in percentage of oxygen saturation (79.39±1.38%) corresponds to good quality water (MEDD and Water Agency, 2003)[26] .…”

Physico-chemical and bacteriological characterization of surface waters for domestic use: Case of river waters in M'pody village (Anyama, Ivory Coast)

“…This issue of great concern to the international community is the subject of the sixth sustainable development goal (UNRIC, 2020). Access to safe drinking water is therefore an essential condition for health, a basic human right and a key component of effective health protection policies (Moussima et al, 2020). Therby, water is not only an essential element for the functioning of any ecosystem, but also essential for human activities (agriculture, industry) and our everyday life (domestic use, leisure) (Mokeddeme et al, 2017).…”