Evaluation of Metal Contamination of Sediments around an Industrial Gold Mine in Côte d’Ivoire: The Example of Arsenic

Abstract

The Tongon gold mine produces millions of tons of waste rock and tailings which are stored in dumps around the mine. This mine waste is contaminated with arsenic. Arsenic has acutely toxic effects on aquatic life within polluted areas. The potential for contamination of the area’s aquatic environment is apparent. Therefore the objective of this paper was to evaluate the arsenic contamination of the sediments around the industrial gold mine in Côte d'Ivoire using inductively coupled plasma mass spectroscopy (NexION 2000 ICP-MS, USA) after aqua regia acid digestion. In addition, the metal contamination indices were used to evaluate the degree of arsenic contamination in the sediments. The obtained results indicated that the sediments in the industrial area of the Tongon gold mine have high arsenic concentrations in the proximity of pits and dumps. The geoaccumulation index (-0.09 < I_geo < 2.20) and the pollution load index (0.93) revealed that the sediment is moderately contaminated with arsenic. These findings suggest an ecological risk and therefore the need for environmental monitoring, supported by the elaboration of an effective remedial action strategy to minimize local pollution and contamination.