Assessment of the Pollution Status of the Solid Waste Disposal Site of Addis Ababa City with Some Selected Trace Elements, Ethiopia

The study was aimed at determining the levels of various heavy metals present in the soil and leachate of the Addis Ababa solid waste dumpsite and its potential ecological and public health risk. Six soil and six leachate samples were analyzed from December 15, 2009 to January 10, 2010. The results indicated that amongst the minerals studied, the levels of Aluminum (Al) was the highest and it ranged between 24720 and 56825 ppm. The concentration of heavy metals viz. zinc (Zn), chromium (Cr), nickel (Ni), cobalt (Co) and lead (Pb) in the soils samples of the dumpsite and nearby open land were found higher than the internationally acceptable limit for the soil. The leachate leads to a surface water stream and it had 99.48%, 95.4%, 93.9%, 85.47%, 84.56%, 83.85%, 81.78%, 77.1%, 56.26%, 9.09% increment in the concentrations of Cr, cadmium (Cd), Pb, potassium ( K), manganese (Mn), magnesium (Mg), Ni, Co, iron (Fe) and Zn respectively when compared the control. No difference was observed in concentrations of trace elements between soil (of the dumpsite) and the nearby grazing land. This study confirms that continuous application dumping of all categories of solid waste on land resulted in accumulation of metals in receiving soils and release of concentrated leachate to the environment which further enters the food chain in form of meat and milk. In the long term it is expected to create a potential food hazard and hence it is recommended that a modern sanitary landfill be constructed immediately with facilities to monitor the ground water contamination facilities, besides remedial measures be undertaken immediately to clean up the existing area using appropriate remediation technologies.