Environmental Impact of Artisanal Gold Mining in Luku, Minna, Niger State, North Central Nigeria

Abstract

The evaluation of environmental impact of artisanal gold mining was carried out in Luku, Minna, North Central Nigeria, to evaluate environmental hazards associated with artisanal gold mining through field work and Laboratory analyses. During the field work, observations of the whole mining site were made so as to evaluate the physical impact of mining and representative soil samples were randomly collected from the surface from mined and un-mined areas within the mining sites. The soil samples were analysed at the National Geo-science Research Laboratory (NGRL), of Nigerian Geological Survey Agency (NGSA), Kaduna for trace elements using X-Ray Fluorescence (XRF) method. The average concentration of these elements was compared with the published crustal average concentration of the elements in upper continental crust. Results of field observation reveal that mining activity resulted in lot of physical environmental impact such as land degradation, destruction of vegetation, erosion of soils and degrading water quality. Results from the laboratory analyses show that soils are contaminated with elements such as Pb (85.73 ppm), As (9.27 ppm), Cu (56.46 ppm), Zn (31 ppm), Ni (85.55 ppm), Mn (283.73 ppm), Cd (1.68 ppm), Co (10.91 ppm), Mo (0.91 ppm), Hg (0.27 ppm), Ag (0.73 ppm), and Zr (143.27 ppm). These elements in the soil get accumulated in plants and animals, and are passed on to human through the food chain. Also, these elements can find their way to surface and ground water making the water unsuitable for human consumption. It may cause slow growth rate in plants and respiratory problem, liver and kidney damage in man.