Determination of the level of selected heavy metals And contributing factors at selected garages soil in Jimma town, south west, ethiopia

Abstract

Background: Nowadays, Jimma town is characterized as one of the fastest-growing towns and centers of business in the Oromia region. Besides this, the number of garages is rapidly increasing. This implies that, whether it is a large or small scale garage, it releases different types of a pollutant that have significant potential impact to the environment. Due to the heavy metals it contains, garage debris is a significant contributor to environmental contamination. It is also the major challenge in developing countries due to the absence of appropriate hazardous waste management and less emphasis given to garage and auto mechanical waste. Objectives: The aim of this study was to determine the levels of heavy metals lead, chromium, zinc, and copper and contributing factors in selected garages soil in Jimma town. Methods: Cross sectional study design was conducted from May 5 to August 10, 2022 in Jimma town, south west Ethiopia. A total of 21 composite soil sample was collected purposely from six Garages, from which three control samples was collected outside garages. The collected samples were analyzed for lead, chromium, zinc, and copper to determine the level of contamination in garage soil by Agilent 4200 Microwave Induced Plasma Atomic Emission Spectrometer. The contributing factors such as pH, EC and moisture content of the soils was also measured. Results: The mean concentration of metals obtained in each site at 0-10 cm depth by MP-AES (mg/kg) was; G1; ZN: 677.50±82.50, Cr: 48.75±11.25, Cu: 132.50±112.50, Pb: 1.48±0.303, (G2;Zn: 430.00±7.500,Cu: 131.25±11.25,Cr: 92.50±2.500,Pb: 1.58±0.004,(G3;Zn: 396.25±136.25,Cu: 48.75±11.25,Cr: 56.25±3.750,Pb: 1.03±0.056,(G4;Pb: 1.29±0.205,Cr: 140.00±20,Cu: 177.50±20,Zn: 458.75±58.75,(G5;Zn: 335.0±15.00,Cr: 57.50±25.00,Cu: 82.50±15.00,Pb: 2.21±0. 133, (G6; Pb; 0.48±0.001, Cr: 123.75±56.25, Cu: 686.25±421.25, Zn: 515.00±140.00). The level of these metals exceed the WHO limit in G4 and G6 except lead.in these study the level of lead and chromium in G1, G2 was within the WHOlimit.in G3 the level of Zinc exceeds the WHO limit. Conclusion: Human activities that result in the toxicity of heavy metals in the soils are the main cause of soil pollution. One of the main causes of the rise in heavy metal concentration in the soils of Jimma, Ethiopia, is garages