Assessment of Some Heavy Metals Contamination in Some Vegetables (Tomato, Cabbage, Lettuce and Onion) in Ethiopia: A Review

Heavy metals in the soil are associated with various chemical forms that related to their solubility nature which directly bear on their mobility and biological availability. Vegetable and other crops can absorb heavy metals from soil and, deposited on the part of their tissues. The aim of this review is to assess the extent of heavy metals in some vegetables (lettuce, tomato, cabbage and onion) which are grown in different part of Ethiopia. These vegetables are staple and common vegetables consumed by all classes of Ethiopians, due to high consumption rate of these vegetables. Vegetables are vital to human being diet as they contain essential components need by the human body such carbohydrates, proteins, vitamins, minerals and also trace elements. Consumption of vegetables like tomato, lettuce, cabbage and onion are is one of the pathways by which heavy metals enter the food chain. According to different studies in Ethiopia the concentration of heavy metals in vegetables has been compared with the standard value recommended by WHO/FAO, and other organization are recorded comparative average concentrations and above the recommended limit. The higher concentration of heavy metal in vegetables might be due industrialization and agricultural activities. Based on facts obtained from different studies we suggests concerned official body (ies) to take the necessary precaution measures for agricultural activities, polluted factory effluents, gasses and solid wastes and other heavy metal source.