Tessema, Merid (PhD)Tesfaye, Kassahun2020-09-282023-11-092020-09-282023-11-092020-02-02http://etd.aau.edu.et/handle/12345678/22475Both natural and human activities adds heavy metals to soil, natural activities have a little effect on soil pollution, however soil pollution mainly causes from anthropogenic activities of humans that lead to heavy metals toxicity into the soils. Garages are one of the major sources of increase in heavy metal concentration in soils of Addis Ababa, Ethiopia. Three garage sites were selected for the study, which include; Zenebework (Z.W), Amanuel (A) and Kotebe (K). Heavy metals in the soil samples at 0-10 cm depth were collected. After proper sample pretreatment, the type and volume of reagents to be used, digestion temperature and digestion time were optimized. Then using the optimized conditions sample preparation was made and levels of metals such as Lead (Pb), Zinc (Zn), Chromium (Cr), Copper (Cu) and Aluminium (Al) in each soil were determined by microwave plasma atomic emission spectrometry (MP-AES). The accuracy of the optimized procedure was evaluated by analyzing the digestion of the spiked samples with standard solution and the percentage recoveries varied from 86% to 112%. The mean concentration of metals obtained in each site at 0-10 cm depth by MP-AES (mg/kg) were; (Z.W; Zn: 422 ± 31.8, Cr: 58 ± 6.8, Cu: 71 ± 6.1, Al: 47601 ± 2350), (A; Zn: 657 ± 42, Cr: 146 ± 12.8, Cu: 307.5 ± 14.4, Al: 16132 ± 664), (K; Zn: 447 ± 20, Cr: 57 ± 4.5, Cu: 188 ± 6.1, Al: 17486 ± 953.6). The levels of metal concentration in the soils from these experimental sites were higher than the recommended limits given by World Health Organization (WHO). In these study; Lead (Pb) is below the detection limit.enAnthropogenic ActivitiesAddis AbabaGarage SoilHeavy MetalsConcentration of MetalsMicrowave Plasma Atomic Emission SpectrometryRecommended LimitsThesis