African Journal of
Environmental Science and Technology

  • Abbreviation: Afr. J. Environ. Sci. Technol.
  • Language: English
  • ISSN: 1996-0786
  • DOI: 10.5897/AJEST
  • Start Year: 2007
  • Published Articles: 922

Full Length Research Paper

Assessment of heavy metals in vegetables irrigated with Awash River in selected farms around Adama town, Ethiopia

Girmaye Benti
  • Girmaye Benti
  • Department of Biology, Dilla University College of Natural and Computational Science, P. O. Box.419 Dilla, Ethiopia
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  •  Received: 13 May 2014
  •  Accepted: 26 June 2014
  •  Published: 31 July 2014

Abstract

A study was conducted at Melka Hida and Wonji Gefersa farms where Awash River was used for cultivation of vegetable crops to assess heavy metal contamination of vegetables. To what extent these vegetables are contaminated is not known. Three leafy vegetable samples, namely, cabbage (Brassica oleracea Linn.), lettuce (Lactuca sativa) and spinach (Spinacea oleracea) from Melka Hida and Wonji Gefersa farms were examined for heavy metal (Cd, Cr and Pb) contamination using atomic absorption spectroscopy. The results indicate that the heavy metals in vegetables of Melka Hida farm were higher than those of the vegetables in Wonji Gefersa farm. In all the samples analyzed, the concentration of Pb and Cd was more than the maximum limit and their levels varied from 0.31 to 0.65 and 0.21 to 0.40 mg/kg, respectively. However, the level of chromium was generally within the normal range in cabbage (0.85 and 0.29 mg/kg) and spinach (1.30 and 1.06 mg/kg) from Melka Hida and Wonji Gefersa farms, respectively, except in lettuce from Melka Hida farm, 2.4 mg/kg. The high levels of these heavy metals place the consumers of these vegetables grown within the study area at health risk with time unless an urgent step is taken by relevant agencies to address this issue.

 

Key words: Awash River, contamination, trace elements, vegetables.