Assessing Heavy Metal Contamination in Soils around Ashaka Cement Factory, Gombe State, Northeastern Nigeria using Ecological Pollution Indices

Abstract

The mining sector is an important segment of Nigerian’s socio-economic development especially now that the price of crude oil has fallen drastically at the international market. The impact of limestone mining and processing on soil quality in Ashaka and environs was investigated using ecological pollution indices. Soil samples were collected from Ashaka, Badebdi, Gongila, Juggol, Feshingo and Jajami communities at depths of 0.0 m, 0.5 m and 1.0 m respectively and analyzed for their heavy metal content (Cd, Fe, Cu, As, Ni, Pb, Cr and Zn). The results of the analyses were interpreted using geo-accumulation index (Igeo), contamination factor (CF), degree of contamination (Cd), enrichment factor (EF) and correlation analysis (CA). The result of the computed Igeo indicates that the soil in the area is unpolluted while CF values show low to moderate contamination. The calculated EF values show no enrichment to minimal enrichment while Cd values reveal low degree of contamination for the soils in the area. The correlation coefficient further reveals a very low correlation among the metals which implies a low pollution status. The mean concentrations of the metals were found to be far below their respective average crustal abundance, which is an indication that the soil in the study area has not witnessed any serious contamination. However, the concentration of cadmium in some locations was slightly higher than the average crustal abundance. It may be attributed to the anthropogenic activity domiciled in the area. A periodic monitoring of soil quality level in the area is advocated.