[ Contamination métallique des environnements d’exploitation artisanale de l’or: Cas du département de Bangolo (Ouest, Côte d’Ivoire) ]
Volume 81, Issue 2, November 2025, Pages 120–130
Yao Kouadio Assemien François1, Ouédraogo Moussa2, Ouattara Ismaïla3, COULIBALY Léréyaha4, Kouadio Kolatrin Elie5, Ouattara Pétémanagnan Jean-Marie6, and Yao Koffi Blaise7
1 Unité de Formation et de Recherche en Sciences Géologiques et Minières, Université de Man, Côte d’Ivoire
2 Department of Geological and Mining Sciences, University of Man, Man, Cote d’Ivoire
3 Department of Geological and Mining Sciences, University of Man, Man, Cote d’Ivoire
4 Department des mines et réservoirs, Université de Man, UFR des sciences Géologiques et Minières, Man, Côte d’Ivoire
5 Department of Geological and Mining Sciences, University of Man, Man, Cote d’Ivoire
6 Laboratoire d’Environnement et de Biologie Aquatique, Sciences et Gestion de l’Environnement, Université NANGUI ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire
7 Department of Soil, Water, and Geomaterials Sciences, Félix Houphouët-Boigny University, Abidjan, Cote d’Ivoire
Original language: French
Copyright © 2025 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Although illegal gold panning is prohibited and punishable by law in Côte d’Ivoire, numerous sites continue to thrive in rural areas, bringing with them significant environmental nuisances. The western region of the country hosts a high concentration of gold panning sites. This study aims to assess the potential intensity of metal contamination (As, Pb, Cu, Ni, Zn, Cr, Hg, and Cd) in soils and to determine the associated ecological risk. Eight (8) soil samples were collected at a depth of 15 cm from areas influenced by gold panning activity in the Bangolo department. Laboratory chemical analyses and statistical treatments were conducted to evaluate the contamination intensity through the calculation of contamination factors and the geo-accumulation index (Igeo). Additionally, the ecological risk associated with soil metal contamination was assessed. The results showed that As, Ni, and Cr concentrations in samples S3, S4, S5, S6, S7, and ST exceeded average concentrations typically found in the upper continental crust. The highest average concentrations were recorded for Cr (134.34 mg/kg), Cu (41 mg/kg), and Ni (34.43 mg/kg). The average Pb and As concentrations in the studied soils were 7.92 mg/kg and 5.79 mg/kg, respectively. Overall, soil metal contamination ranged from low to moderately severe. Chromium and arsenic contamination were the highest, with contamination factors reaching up to 5.37 and 6.75, and Igeo values of 1.84 and 2.17, respectively. Sample S6 was the most contaminated, while S1 showed no contamination due to its sandy nature. The resulting ecological risk is currently low, with all risk index (RI) values below 150.
Author Keywords: geochemistry, metal contamination, soil, gold panning, Bangolo.
Volume 81, Issue 2, November 2025, Pages 120–130
Yao Kouadio Assemien François1, Ouédraogo Moussa2, Ouattara Ismaïla3, COULIBALY Léréyaha4, Kouadio Kolatrin Elie5, Ouattara Pétémanagnan Jean-Marie6, and Yao Koffi Blaise7
1 Unité de Formation et de Recherche en Sciences Géologiques et Minières, Université de Man, Côte d’Ivoire
2 Department of Geological and Mining Sciences, University of Man, Man, Cote d’Ivoire
3 Department of Geological and Mining Sciences, University of Man, Man, Cote d’Ivoire
4 Department des mines et réservoirs, Université de Man, UFR des sciences Géologiques et Minières, Man, Côte d’Ivoire
5 Department of Geological and Mining Sciences, University of Man, Man, Cote d’Ivoire
6 Laboratoire d’Environnement et de Biologie Aquatique, Sciences et Gestion de l’Environnement, Université NANGUI ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire
7 Department of Soil, Water, and Geomaterials Sciences, Félix Houphouët-Boigny University, Abidjan, Cote d’Ivoire
Original language: French
Copyright © 2025 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Although illegal gold panning is prohibited and punishable by law in Côte d’Ivoire, numerous sites continue to thrive in rural areas, bringing with them significant environmental nuisances. The western region of the country hosts a high concentration of gold panning sites. This study aims to assess the potential intensity of metal contamination (As, Pb, Cu, Ni, Zn, Cr, Hg, and Cd) in soils and to determine the associated ecological risk. Eight (8) soil samples were collected at a depth of 15 cm from areas influenced by gold panning activity in the Bangolo department. Laboratory chemical analyses and statistical treatments were conducted to evaluate the contamination intensity through the calculation of contamination factors and the geo-accumulation index (Igeo). Additionally, the ecological risk associated with soil metal contamination was assessed. The results showed that As, Ni, and Cr concentrations in samples S3, S4, S5, S6, S7, and ST exceeded average concentrations typically found in the upper continental crust. The highest average concentrations were recorded for Cr (134.34 mg/kg), Cu (41 mg/kg), and Ni (34.43 mg/kg). The average Pb and As concentrations in the studied soils were 7.92 mg/kg and 5.79 mg/kg, respectively. Overall, soil metal contamination ranged from low to moderately severe. Chromium and arsenic contamination were the highest, with contamination factors reaching up to 5.37 and 6.75, and Igeo values of 1.84 and 2.17, respectively. Sample S6 was the most contaminated, while S1 showed no contamination due to its sandy nature. The resulting ecological risk is currently low, with all risk index (RI) values below 150.
Author Keywords: geochemistry, metal contamination, soil, gold panning, Bangolo.
Abstract: (french)
Bien que l’orpaillage clandestin soit interdit et réprimé, en Côte d’Ivoire, de nombreux sites continuent de prospérer dans les zones rurales avec leurs corollaires de nuisances environnementales. La région de l’ouest concentre de nombreux sites d’orpaillage. Cette étude vise à évaluer l’intensité de la contamination métallique (As, Pb, Cu, Ni, Zn, Cr, Hg et Cd) potentielle des sols et d’en déterminer le risque écologique associé. Ainsi, 08 échantillons de sol ont été prélevés à 15 cm de profondeur dans les zones influencées par l’activité d’orpaillage dans le département de Bangolo. Des analyses chimiques au laboratoire ainsi que des traitements statistiques ont été effectués pour déterminer l’intensité de la contamination à travers l’évaluation du facteur de contamination et de l’indice de géo-accumulation. De même, le risque écologique associé à la contamination métallique des sols a été déterminé. Les résultats ont montré que les teneurs en As, Ni et Cr des échantillons S3, S4, S5, S6, S7 et ST sont supérieures aux concentrations moyennes enregistrées dans la croute continentale supérieure. Les concentrations moyennes les plus élevées sont celles du Cr (134,34 mg/kg), Cu (41 mg/kg) et Ni (34,43 mg/kg). Les teneurs moyennes des sols étudiés en Pb et As sont respectivement de 7,92 et 5,79 mg/kg. D’une manière générale, la contamination métallique des sols varie de faible à modérément sévère. La pollution en chrome et en arsenic sont les plus élevées avec des facteurs de contamination allant jusqu’à 5,37 et 6,75 et un Igéo de 1,84 et 2,17 respectivement. Le sol S6 est le plus contaminé tandis que S1 est sans contamination, en raison de sa nature sableuse. Le risque écologique qui en découle est, pour l’instant, faible avec des RI, tous, inférieurs à 150.
Author Keywords: géochimie, contamination métallique, sol, orpaillage, Bangolo.
How to Cite this Article
Yao Kouadio Assemien François, Ouédraogo Moussa, Ouattara Ismaïla, COULIBALY Léréyaha, Kouadio Kolatrin Elie, Ouattara Pétémanagnan Jean-Marie, and Yao Koffi Blaise, “Metal contamination in artisanal gold mining environments: The case of the Bangolo department (West, Cote d’Ivoire),” International Journal of Innovation and Scientific Research, vol. 81, no. 2, pp. 120–130, November 2025.
