Heavy Metals Contamination of Soils within Mining Sites in Ebonyi North Central Zone, Ebonyi State, Nigeria

Abstract

  Mining activities adversely affect the qualities of the earth crust through accumulation of heavy metals in the soil. This study is planned to assess the heavy metal contamination within mining sites in Ebonyi north central zone, Ebonyi State, Nigeria. The study involves collection of three soil samples from different mining site within Ebonyi north central zone and a control. The soil samples were collected from a depth of 0-20 cm and  taken  to laboratory for analyses using Standard methods. The heavy metals (Mgkg-1) concentrations range from 0.021-2.217; 14.55-297.21; 31.50-182.668; 0.01-417.667; 0.01-3.564; 1.126-1.774 and 2.925-5.615 for Copper (Cu), Iron (Fe), Zinc (Zn), Lead (Pb), Cadmium (Cd), Nickel (Ni) and Chromium (Cr) respectively. The pollution intensity was assessed using geoaccumulation index which revealed Cu, Ni and Cr unpolluted in all the mining sites, Cd moderately polluted to strongly polluted in all the mining sites, Zn unpolluted to moderately polluted in all the mining sites while Fe was unpolluted in all the sites except in Enyim-Agalagu. Other exception is Pb having unpolluted in Obichie-Ameka, unpolluted to moderately polluted in Enyim-Agalegu and strongly polluted in Enyigba. The consequences of  observed pollution include introduction of pollutants into the soil and its accumulation into microorganisms that live in the soil making the soil unproductive and unsafe for agricultural purposes. This study recommends appointment of community stakeholders from mining areas to relate with Ministry of Environment for continuous monitoring of mining sites. They should request for management approach for regulation of mining activities within the locations.