Metal Concentration in Vegetables Grown in the Hydrothermally Affected Area in Ethiopia

Being at the top of the food chain, man is the main receiver of unwanted metals through vegetable consumption. The situation is exacerbated in developing countries due to the lack of regulations where people consume vegetables grown using polluted soil and water. Most of the research works conducted in Addis Ababa revealed that the concentration of metals in vegetables reached toxic level and it was attributed, exclusively, to the industrial sources. To investigate the impact of natural environmental changes, in the current work, vegetable, water and soil samples were collected from the northern part of the city of Addis Ababa where there is no industrial activities and Ziway area in the Main Ethiopian Rift. Ziway area was selected as a control point due to its location, which is away from the industrial activities. Populated area and rural area were compared to investigate for the concentrations of metals such as Cd, Cr, Pb and Zn, in soils, vegetables and irrigation water in order to understand the magnitude of metals in the edible part of the vegetables. The results indicate that vegetables that are grown in industrially free area of northern part of Addis Ababa, which are destined to the domestic consumption, contain high level of metals that are generated from geogenic sources. Until recent days, industrial pollution was attributed to be the main source of metals in the city’s irrigation water and irrigated vegetables, however, natural sources are widespread in the city. It is presumed that long time consumption of vegetables loaded with metals could pose health risk.