Investigation of Heavy Metals Status in Vegetables Grown at Awash and Jemo-3 Farm Sites, Ethiopia

No Thumbnail Available



Journal Title

Journal ISSN

Volume Title


Addis Ababa University


Food safety is a big public concern around the world. Vegetables are an essential ingredient in the human diet as they contain nutrients and trace elements which have potential health benefits. They are known to accumulate trace metals which are essential as well as toxic. Ingestion of vegetables containing heavy metals is one of the main routes by which they enter the human body, which gradually causes human diseases. An optimized wet acid digestion procedure has been adopted to digest the plant and soil samples. The validity of the method was evaluated by spiking the sample with a standard of the selected metals. For water samples, the United States environmental protection agency (USEPA) 3005A (1992) method was applied. From analysis of soil the mean concentrations (mg/kg) of Pb and Cr were observed to be 18.77±0.54, 30.89 ±0.18 respectively. However, Cd was not detected. For irrigation water, the levels of all heavy metals were found to be below the detection limit. For vegetables, only lead was detected and its mean concentrations (mg/kg) were obtained to be 0.31 ±0.02 for cabbage, 0.40±0.03 for lettuce and 0.33 ±0.06 for spinach. The metal concentrations determined on the farm were compared to the standards, and Pb in vegetables was found to be above the permissible limit. The objective of this research was to investigate the source and level of heavy metals (Pb, Cr, and Cd ) contamination in irrigation water, soil, and various types of vegetables, including cabbage, lettuce, and spinach, cultivated on an Awash vegetable farm. The research findings made it clear that the contamination of those soil and vegetables with these heavy metals was primarily due to their geogenic origin, so the study area should be treated to reduce the health risk of humans due to exposure to toxic levels.



Heavy metals, vegetables, contamination, optimization