Assessment of Trace Elements Levels in Sediment and Water in Some Artisanal and Small-Scale Mining (ASM) Localities in Ghana

The concentrations of eight trace elements, Cadmium (Cd), lead (Pb), iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), mercury (Hg) and arsenic(As) in sediment and water were assessed in four artisanal and small-scale mining(ASM) localities in the Amansie West District (6°282 N 1°532 W) of Ghana along two river courses from May 2011 to July 2011. Triplicate water and sediment samples were randomly taken at five different points at each of the localities and the elements determined using Atomic Absorption Spectrophotometer (AAS). Using the Geo-accumulation Index ( Igeo) assessment, the sediments were found to be polluted to different degrees with Cu (Uncontaminated to moderately contaminated/Moderately contaminated), Hg (Uncontaminated to moderately contaminated/Moderately contaminated) and As (Moderately contaminated/Moderately to strongly contaminated). The Enrichment Factor (EF) indicated human influence- artisanal mining activities on the sediment concentration of Cd and Pb for all the localities and only some of the localities for the rest of the trace elements. The elements are major sediment pollutants ( EF> 2) in one or more of the localities. The Igeo and EF gave diverse status of the sediment qualities of the localities. Cd, Pb, Hg and As water concentrations in the four artisanal mining localities were all found to be above the WHO maximum acceptable of levels for drinking water. Inhabitants in the mining localities face the risk of getting various diseases by drinking the waters contaminated with the trace elements