Pollution status of soil within the vicinity of Automobile mechanic workshops in Owerri Municipality, Nigeria

Abstract

Authors: Emeka Chima Ogoko, Kelle Henrietta Ijeoma & Enete Uchenna Oliver

Received 18 November 2019/Accepted 29 December 2019

Physicochemical parameters and heavy metal ions in soils within the vicinity of some mechanic workshops in Owerri metropolitan in Imo State were investigated. Soil samples were taken from mechanic workshops around Aba road, Orji and Avu. AOAC methods were used in the analysis of soil physicochemical parameters while heavy metals ions determination was performed using Atomic Absorption Spectrophotometer. The results obtained indicated a marked variation in the levels of physicochemical properties and heavy metal ion concentrations within locations and soil depth. Soil samples from Avu mechanic workshop had the highest level of Zn, Pb and Cu with mean concentrations of 26.79, 1.12 and 2.70 mg/kg respectively while soil samples from Orji had the least, with mean concentrations of 19.63, 0.05, 1.05, 0.77 and 9.46 mg/kg for Zn, Ni, Cu, Cd and Fe respectively. Soil samples from Aba road mechanic workshops recorded the highest mean values of 1.25 and 21.80 mg/kg for Cd and Fe ions respectively. These values were higher than the concentrations obtained for the control. The results revealed that Avu mechanic workshop was the most contaminated, while Orji had the least contaminants. Physicochemical analysis indicated that Orji had the highest amount of SO₄^2-,NO^3- and pH with mean values of 34.91, 12.90 and 5.99 mg/kg respectively while soil samples from Avu were characterised with highest level of PO₄^3-, total organic matter and total organic carbon with mean value of 3.69 mg/kg, 1.93 % and 1.12 % respectively. Calculated enrichment factor of Cd²⁺ ranged from 1.38 to 5.29, indicating soil contamination by Cd²⁺ due to anthropogenic activities.