Geo-Environmental Hazard Assessment of Abandoned Gold Mine Pits at Angwan Kompani Minna, Niger State

This study assessed the Geo-environmental hazard of abandoned gold mine pits at Angwan Kompani, Minna, Niger State. Six water samples, five soil samples and two rock samples were collected for laboratory analysis. Atomic absorption spectrometer (AAS) was used to analyse water and soil samples, while rock samples were analysed by X-ray fluorescence (XRF) for heavy metals present both in oxide form and elemental distribution. The study showed that the main contaminants in water sample are lead (Pb), Cadmium (Cd), Nickel (Ni) and Manganese (Mn) having an average concentration of 0.118mg/l, 0.041mg/l, 0.074mg/l, and 1.239mg/l respectively. The major contaminant in soil samples were found to be Iron (Fe), Nickel (Ni), Manganese (Mn) and Zinc (Zn) with the average concentration of 474.2mg/kg, 0.97mg/kg, 6.41mg/kg, and 29.62mg/kg respectively. The result of the heavy metals in both soil and water samples were found to be above the maximum allowable limit of World Health Organisation (WHO) standards and Nigerian standard for drinking water quality (NSDWQ) for domestic water. Thus, the abandoned mine pit in the study area have tendency of negativity affecting the residents due to high concentration of Lead (Pb), Cadmium (Cd), and Nickel (Ni) possibly resulting cancer, metal disorder and effect on the kidney. The results of the X-ray fluorescence (XRF) carried out on the rock for elemental distribution shows that the sample contained 51.995% O, 0.885% Cl, 1.865% Al and 0.7065% Fe on the average. From the study area, it is shown that the abandoned mine pits in the study area have the tendency to have negative affect on the socioeconomic life of the people and the local residents and sustenance of the general environment, if not properly managed. It is therefore recommended to develop and implement remediation plan to reduce the level of heavy metals in the soil and water around the mine pit.