Author(s): Augustin Kouame N’Guessan, Marius Tanoh Kamelan, Gogbe Zeré Marius and Valentin N’douba

Abstract: Mercury used in gold amalgamation is a global concern and a major source of contamination and dispersion in environmental aquatic of Cote d’Ivoire, mainly in the North where clandestine gold mining activities are a local interest. The aim of this study was to assess the level of total mercury (Hg-T) contamination of sediments from Bagoue River. Water and sediments samples were collected during wet and dry seasons from six stations differently impacted. Spatial and seasonal variations in physical and chemical parameters were assessed. Results revealed that the level of Hg-T in water was 0.68±0.03 µg.L^-1 and in the sediments, dry weight concentration was 0.064±0.01 mg.kg^-1. The Hg-T concentration in sediments was significantly higher (p< 0.05) during the dry season (0.089±0.053 mg.kg^-1) than that recorded in the wet season (0.064±0.039 mg.kg^-1). Ultimately, strong and positive correlations have been observed between Hg-T in sediments and sandy sediments (r = +1), as well as suspended materials (r = +0.85). The pollution status of mercury in sediments according to the geo-accumulation index was uncontaminated (- 47.03) at all the seasons whereas enrichment factor has been moderate over climatic seasons at downstream stations heavily impacted by gold mining. The sandy texture of the River sediments favours the infiltration of mercury and its accumulation in groundwater. As a rate, the health risks associated with the consumption of these waters are potentially high.

DOI: 10.22271/fish.2021.v9.i4b.2536

Pages: 149-158  |  668 Views  145 Downloads

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