Heavy Metal Concentration in Soil and Swiss Chard Grown in the Vicinity of Addis Ababa, Ethiopia

Abstract

Urban and Peri-urban lands are often used for production of vegetables for better market accessibility and higher prices. But most of these lands are contaminated with heavy metals through industrial effluents, sewage and sludge, and vehicular emissions. Vegetables grown in such lands, therefore, are likely to be contaminated with heavy metals and unsafe for consumption. The objective of this study was to determine the concentration of heavy metals in soils, as well as on the leafy vegetable (Swiss chard) grown in the vicinity of industrial areas. The study was conducted from October 2014 to June 2015. Soil and vegetable samples were collected from three vegetable growing farms (Bulbul, Kebena and Akaki ) in the vicinity of Addis Ababa to monitor their heavy metal loads. The analysis was carried out at JIJA laboratory using atomic absorption spectrophotometer (AAS) following the standard laboratory procedures. The final result of the study showed that soil samples collected from Bulbul, Kebena and Akaki sites in two different soil depths showed a significant (p < 0.05) variation in the level of heavy metal loads. Swiss chard samples showed Cr and Zn levels higher than FAO/WHO limits. The level of Cd, Pb and Cu however, were at their safe limits.