GETAHUN MENGIST GELLA2026-01-282024-11https://etd.hu.edu.et/handle/123456789/281Heavy metal pollution of the environment has been a global concern due to its acute and chronic health effects. The consumption of contaminated food and beverages is among the major route of exposure. Khat (Catha edulis) is one of the major cash crops that are widely cultivated and consumed as stimulant in the study area (Tulla Sidama regional state).This work focuses on the physicochemical analysis and determination of selective heavy metals (Cu, Co, Ni, Cr and Pb) concentration in chewable parts of the leaves of the selected Khat varieties (Nole, Dume and Megala) and its support soil samples. Samples were randomly collected from the selective kebeles of the study area and digested using mixture of acids. Analysis of the physicochemical parameters (pH, electrical conductivity and ash content) was carried out by standard method. The determination of the heavy metals was carried out using Flame Atomic Absorption Spectroscopy (FAAS). The physicochemical analysis showed pH (6.21-6.82), electrical conductivity (1.42-1.86), and ash content (1.72-2.17) in soil samples and pH (5.93-6.43), electrical conductivity (1.17-1.54), and ash content (0.63-0.93) in khat samples. The heavy metal analysis showed concentration of Cu, Ni and Co to be 4.33-4.93mg/kg, 2.52-3.26mg/kg and 1.84-2.85mg/kg respectively in khat samples. The levels of these metals in the corresponding soil samples were (8.54-9.96mg/kg), (3.67-4.95mg/kg) and (3.37-4.85mg/kg for Cu, Ni and Co respectively. Pb and Cr were not detected in soil and khat varieties samples. Among the analyzed heavy metals Cu was detected relatively at the highest concentration followed by N and Co in both soil and Khat samples. These findings indicated a positive correlation between the levels of the heavy metals in the soil and the Khat samples. Although Pb, Cr, Cu and Ni were detected below the permissible level, Co was detected above the permissible level stipulated by WHO. Therefore, it can be concluded that continuous consumption of Khat as stimulant might lead to health risks associated with heavy metals.Physicochemical AnalysisHeavy MetalsFlame Atomic Absorption SpectroscopyCatha edulisSoil samplesThesis