The impact of small-scale mining activities on the levels of mercury in the environment: The case of Prestea and its environs

To obtain the baseline information of mercury pollution due to gold mining activities in Prestea and its environs total mercury (T-Hg) concentrations were measured in water and stream sediment. The samples were analyzed by instrumental neutron activation analysis (INAA). They were irradiated and counted without any preconcentration. Higher levels of T-Hg concentration were found in samples at the sites with extensive small-scale galamsey gold mining activities than at the sites with low small-scale galamsey activities. Concentrations varied between 6.80–19.82 mg/l for water and 28.90–84.30 mg/kg in sediment at sites with extensive small-scale mining activities. At low small-scale mining sites concentration levels for T-Hg varied between 0.50–9.10 mg/l and 1.20–22.75 mg/kg in water and sediment, respectively. The concentration levels of T-Hg in water from all the sampling sites are in excess of the WHO tolerable limit of 0.001 mg/l for drinking water.Some financial support for the work from the National Nuclear Research Institute is highly appreciated. The authors thank Messers Nick Opata and Ekow Quagraine, the technicians at the NAA laboratory for their contribution during preparation, irradiation and counting of samples. We also thank the team of reactor operators.