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Objectif : Evaluer le niveau de contamination des eaux souterraines de Zouan-Hounien en élément traces métalliques (ETM).Méthodologie et résultats : Un total de soixante-douze (72) échantillons d’eaux souterraines ont été prélevés en raison de quarante-six échantillons d’eaux de puits (23 puits) et vingt-six échantillons d’eaux de forages (13 forages). Dans ces échantillons, des ETM tels que : Hg, Pb, Cd, As et Fe ont été dosés par spectrométrie d’absorption atomique. Les concentrations moyennes respectives de Fe, Pb, Hg, As et Cd sont de 2233,48 > 3,10 > 1,67 > 1,18 > 0,08 μg.L-1 dans les puits et de 2427,94 > 4,08 > , 2,36 > 1,76 > 0,08 μg.L-1 dans les forages. La valeur moyenne du degré de contamination (Dc) dans les puits et les forages est supérieure à 3, indiquant ainsi une forte contamination des eaux souterraines. Avec des valeurs moyennes de l’indice de pollution par les ETM (HPI) inférieures à la valeur seuil de 100, ces eaux restent faiblement polluées dans l’ensemble. Pourtant, deux puits et deux forages ont enregistré une forte pollution des eaux, avec des valeurs supérieures à 100.Conclusion : L’indice de pollution des eaux souterraines par les ETM appliqué aux eaux souterraines révèle que les eaux de puits et de forages sont de bonne qualité, à l’exception de deux puits et deux forages. Le mercure reste le principal élément qui contribue à la toxicité des eaux. Sa présence dans les eaux est due à l’effet des activités d’orpaillage ancien et actuel dans la zone. Une sensibilisation sur les impacts de l’orpaillage sur les ressources en eau est à mener au sein des orpailleurs afin de réduire l’utilisation du mercure. Une consommation prolongée de ces eaux peut entrainer des problèmes graves de santé publique. Objective : Assess the level of contamination of Zouan-Hounien groundwater with metallic trace elements (ETM).Methodology and results: A total of seventy-two (72) groundwater samples were taken that is forty-six well water samples (23 wells) and twenty-six borehole water samples (13 wells). In these samples, ETMs such as: Hg, Pb, Cd, As and Fe were determined by atomic absorption spectrometry. The respective average concentrations of Fe, Pb, Hg, As and Cd are 2233.48> 3.10> 1.67> 1.18> 0.08 μg.L-1 in the wells and 2427.94> 4 , 08>, 2.36> 1.76> 0.08 μg.L-1 in boreholes. The average value of the degree of contamination (Dc) in wells and boreholes is greater than 3, thus indicating a strong contamination of groundwater. With average values of the ETM pollution index (HPI) below the threshold value of 100, these waters remain slightly polluted. However, two wells and two boreholes recorded heavy water pollution, with values greater than 100. The correlation matrix carried out between the ETM and the HPI reveals that Hg is the main element, which contributes to the toxicity of the water.Conclusion: The ETM pollution indices for groundwater applied to waters revealed that well and borehole water are of good quality, with the exception of two wells and two boreholes. However, mercury remains the main element that contributes to the toxicity of water. Its presence in the waters is due to the effect of old and current gold panning activities in the area. Thus, raising awareness of the impacts of gold panning on water resources is to be carried out among gold panners in order to reduce the use of mercury. Prolonged consumption of these waters can lead to serious public health problems.

The problem of drinking water supply in Abidjan Autonomous District is acute. The objective of this study is to assess the quality of Aghien Lagoon waters with a view to their use to make up drinking water deficit. To do this, French Association of Standardization methods were used for determination of various parameters of 48 samples of lagoon waters. Piper diagram was used for waters hydrochemical classification, as well as Principal Component Analysis (PCA) for determining the processes responsible for their mineralization. The mean values of the physical and chemical parameters (pH, Ca2+, K+, Cl-, Na+, Mg2+, PO43-, SO42-, CE, TDS, DBO5, NO3-, NO2-, Cd, Pb, Zn and Cu) comply with the French values required for surface fresh waters intended for drinking water production. On the other hand, mean concentrations of NH4 + (36.88 mg / L) and Fe (1834.48 μg / L) and turbidity (14.98 NTU) are higher than these regulatory limits. Aghien lagoon waters consist of 54.55% of chlorinated water and 45.45% of bicarbonate water. The chemistry of these waters is controlled by rainfull, the weathering from rocks of the watershed, decomposition of organic matter, fertilizers from agricultural activities, and the weathering of silicate minerals from the underlying sediments. The latter seems to play a minor role in hydrochemistry, due to the relatively short residence time. On the whole, Aghien Lagoon waters could be used for the production of drinking water., Environmental and Water Sciences, public Health and Territorial Intelligence Journal, Vol. 1, No 2 (2017)