Analysis of Selected Heavy Metals Concentrations in Roadside Soils: Adama, Oromia region, Ethiopia

Abstract

Heavy metals, such as Cu, Zn, Cd and Pb are common pollutants in urban environments mainly due to high traffic emissions. The present work was aimed to determine the level of Cu, Zn, Cd and Pb concentrations in high traffic density roadside soils of Adama city, Oromia region, Ethiopia. The soil samples were collected from three roadside soils (both sides) of the selected sites symmetrically at distances in the range of 0-50, 50-100 and 100-300 meters from the main road of the city. All the samples were analyzed for the concentrations of Cu, Zn, Cd and Pb using flame atomic absorption spectrometric (FAAS) method. The levels of Cu, Zn and Pb in the roadside soils were found to vary from 20.49 to 45.01, 34.22 to 46.71 and 47.84 to 69.28 mg kg^-1, respectively. The level of Cd was found below the detection limit. The levels of heavy metals in both sides of the roadside soils exhibited a significant decrease with the increasing distance from the road and a positive correlation was found between the metal concentrations. The highest level of Pb, Cu, and Zn in the soil samples was found close to the main road and observed positive correlation among the metal concentrations. The indicated pollution due to vehicles emission will be a potential threat for the city and expect strict measures to reduce harmful emissions.