Assessment of the impact of gold panning on water quality in the locality of Gregbeu (Central-West, Cte dIvoire)

Gold panning has expanded significantly in recent decades in several areas of Côte d’Ivoire. This practice, which involves the use of toxic chemicals, has significant health and environmental consequences, particularly for drinking water resources. This study focused on assessing the quality of surface water and well water in the locality of Gregbeu, in the central-western part of the country, a region marked by intense informal gold mining activity. The main objective was to evaluate the microbiological and physicochemical quality of water resources intended for human consumption. A sampling campaign was conducted at five surface water sites and five wells, followed by physicochemical and microbiological analyses in accordance with International Organization for Standardization (ISO) and Association Française de Normalisation (AFNOR) standards. The results revealed widespread contamination by fecal indicator bacteria (Escherichia coli, fecal streptococci, and Clostridium perfringens), exceeding the thresholds set by the World Health Organization (WHO). The presence of Clostridium in wells suggests past or chronic contamination. High concentrations of BOD₅ (5.75 mg/L), mercury (0.009 mg/L), and electrical conductivity (134 µS/cm) were observed in surface waters. Correlation matrices showed strong relationships between physicochemical parameters, indicating multifactorial pollution predominantly of anthropogenic origin. In conclusion, the bacteriological and chemical quality of water in this area poses a high health risk to the riparian populations. Urgent measures are recommended, including strengthening sanitation infrastructure, regular monitoring of water quality, and raising community awareness.