An Appraisal of Soil Pollution in Oil and Gas Production Environment: A Case Study of Heavy Metals Concentration in Ebocha and Akri Oil Fields

Abstract

Abstract The concentrations of heavy metals in the soil at oil and gas production areas were appraised at Ebocha and Akri communities in Niger Delta region of Nigeria. The pollution/contamination loading indexes of Zinc (Zn), Nickel (Ni), Copper (Cu), and Lead (Pb) in the two communities were determined from soil samples collected in eight locations (in triplicate) in each community using Atomic Absorption Spectrophotometer (AAS). It was observed that Ebocha was slightly polluted with lead (contamination/pollution index, c/p = 1.3), severely contaminated with zinc (c/p = 0.642) and slightly contaminated with copper(c/p = 0.123). Omoku was also slightly contaminated with zinc (c/p = 0.225) while all other sampling locations at Ebocha were very slightly contaminated with zinc, copper nickel and lead (c/p <0.1). Akri was very slightly contaminated in all the sampling locations except for Afia-afor where lead slightly contaminated the soil (c/p = 0.113). A significant correlation (p <0.01) was obtained for zinc (r = 0.65) while there was no significant correlation (0.05 <p <0.01) obtained for Ni (r = −0.14), Cu (r = 0.22), Pb (r = −0.08), Mn (r = 0.38) and Fe (r = 0.54). This correlation showed that the sources of the heavy metals in both communities are different. It was also observed that the increased concentration of heavy metals in oil and gas production areas is more due to other associated human activities in the areas than oil and gas core production activities.