An investigation of mercury distribution in the soils around gold mining area at Dar-Mali locality, river Nile State, Sudan

Abstract

An artisanal gold mining region located in North of Atbara (Dar-Mali locality), River NileState, Sudan (17.82289 to 17.82389N and 33.99974 to 34.02127E) has been studied withthe aim to evaluate the soil contamination with mercury (Hg) using two parameters; (i)Comparison of the Hg concentration with the mean concentrations in world soils, (ii)Enrichment Factor (EF). The results revealed that, the concentrations of the Hg arevarying in the studied area and the highest concentrations were obtained inside themining basins used for gold extraction (2.62 mg kg-1 soil) it is around 29 times more thanmean Hg concentration in world soils, while the lower concentrations are found at recentNile River terrace (0.10 mg kg-1 soil). The results also indicated that the soil samplescollected from inside mining basins had a highest E.F value (352.84) that means, this sitemust be closed and remediation process should be started immediately. While the E.Fvalue of recent Nile River terrace site was 8.74, means, all studied sites have significantcontamination with Hg. The mobility of Hg may have influenced by northeast wind, orwater runoff from mining zone to nearest areas at same wind direction or water flowdirection.