Contamination of soil around an abandoned gold mine tailings dam with trace elements in a small town, northeastern Zimbabwe

Abandoned mine sites are a threat to the quality of the ambient environment. Tailings from an abandoned gold mine were characterised for physicochemical properties. The contamination of soil around a tailings dam with trace elements was assessed using geochemical indices. Tailings had low pH (5.67 ± 0.67), high SO42− content (116.00 ± 23.88 g/kg) and electrical conductivity (3,918.40 ± 673.17 μS/cm). Surrounding soil had elevated concentrations of trace elements which decreased with increasing distance away from the tailings dam, and with increasing depth. The geoaccumulation and degree of contamination indices showed strong to extreme contamination of soil with Cd, Cr and Cu within 10 m from the tailings dam. Soil contamination was high in the downslope and downwind (S, W and SW) directions. Multivariate statistics suggested a common source of Cd, Cu and Pb, the tailings dam. Rehabilitation of the tailings dam may reduce tailings erosion and soil contamination.