Geochemical Baseline and Contamination Level Assessment of Antimony (Sb) in Sediment around Agbaou Gold Mine, Côte d’Ivoire

Abstract

Agbaou is one of the most recent gold mine exploitation sites in Côte d’Ivoire. Little studies are discussed on the geochemical baseline concentration of trace metals in the wetland sediments around Agbaou gold mine. The main objectives of this study were to establish geochemical baseline values and to assess the pollution status of antimony (Sb). The geochemical baseline concentration of Sb (GBCSb) was estimated using linear regression method. In this study, total Sb concentration was analysed in sediment (10 sediment samples) collected around Agbaou gold mine site. The average Sb concentration was 5.63 ± 2.50 µg.g-1 ranging from 2.50 to 11.3 µg.g-1. The spatial distribution of Sb showed a tendency to accumulate near gold mine site. Moreover, the GBCSb (5.72 µg.g-1) was slightly higher than the average concentration found in sediments. GBC of Sb was used to calculate the anthropogenic contribution rate (R) which exhibited a positive value (R > 0) for all samples, indicating that the sediments were influenced by gold mining activities. Due to lack of local baseline value in the study area, the GBCSb obtained could be used as reference value for Sb contamination level assessment in the sediments.