THE EFFECTS OF MINING ACTIVITIES ON THE SOIL QUALITY OF IKWO, EBONYI STATE NIGERIA
Ukpe A. E, Akhionbare S.M.O & Ihejirika C.E
Department of Environmental Management, Federal University of Technology, Owerri Nigeria
Correspondence email: ani.ukpeh@gmail.com
Abstract
Indiscriminate and unrestrained mining activities can result to major negative environmental impacts such as pollution of land and water bodies, thus affecting soil quality; and leading to decrease in soil fertility as well as land degradation and changes in landscape. Therefore, this study was conducted to determine the effects of lead-zinc mining activities on the soil quality of Ikwo in Ebonyi State, and to document the present state of soil physicochemical properties and heavy metal status of soil in the study location. In the study, two major factors were considered: Factor A – distances of sampling points (100m apart) and factor B – soil depth zone (0-15cm and 16-30cm). Three samples labeled MD, TP and WT were collected maintaining a distance of 100m, and these were compared alongside a control established 1.5km away from the mine site. The samples were tested and analyzed for heavy metal concentrations of Pb, Cr, As, Zn, Ni, and Cu, as well as physicochemical parameters such as pH, EC, Ca, Mg, P, K, Na and OM for wet and dry seasons. The study revealed relative concentrations of heavy metals in soils at Ikwo mine sites in the following order: Zn >Pb> Cu > Ni > As>Cr. The Zn content of the soils was extremely high with a range of 1.97 – 9.11 mg/kg. For physicochemical analyses, soil pH, electrical conductivity, phosphorus and total organic matter of the control were higher compared to that of other sampling points, but exchangeable calcium, sodium, magnesium and potassium of most sampling points were lower than the control. The mean concentration of the physicochemical parameters are as follows: pH (6.075 for dry season and 5.85 for wet season), EC (0.383 for dry season and 0.385 for wet season), P (28.69 for dry season and 17.85 for wet season), Ca (331.9 for dry season and 241 for wet season), Mg (356.9 for dry season and 306.7 for wet season), K (5.605 for dry season and 5.308 for wet season), Na (0.385 for dry season and 0.315 for wet season), and OM (0.808 for dry season and 0.833 for wet season). The result of single linear regression model revealed high value of contamination both in physicochemical analyses and heavy metal concentrations in the dry season compared to the wet season. It was recommended the Government’s Ministry of Environment at all levels should adopt a good management approach to the incessant and inadequate mining activities going on in the study location.
Keywords: Mining, Heavy metals, Environmental Impacts, Soil Quality, Ikwo
