Distribution of mercury in the sediments of some freshwater bodies in Ethiopia

• Published in: Toxicological and environmental chemistry 2012-10, Vol.94 (9), p.1678-1687
• Main Authors: Mekonnen, Kebede Nigussie, Ambushe, Abayneh Ataro, Chandravanshi, Bhagwan Singh, Abshiro, Mesfin Redi, McCrindle, Robert Ian, Panichev, Nikolay
• Format: Article
• Language: English
• Subjects: air drying; Atomic absorption analysis; atomic absorption spectrometry; detection limit; differential atomic absorption spectrometry; Environmental Protection Agency; Environmental testing; Evaporation; Guidelines; Lake Awassa; Lake Ziway; Lakes; Mercury; rivers; sediment; Sediments; soil; Soils; surface water; Tinishu Akaki River; Toxicology
• ISSN: 1029-0486; 0277-2248; 1029-0486
• DOI: 10.1080/02772248.2012.728602

Sediment samples were collected from Tinishu Akaki River (TAR), Lake Awassa, and Lake Ziway, Ethiopia for determination of mercury. The air-dried samples were analyzed for mercury with a differential atomic absorption spectrometer after thermal evaporation of bound mercury converting it to its atomic form. Certified reference materials (CRMs) of sediments and soils were used to validate the method. The recovery of mercury from CRMs and sediments was in the range of 95–100%. The limit of detection for the determination of mercury was 50 ng kg⁻¹. The concentration of total mercury in the sediments varied from 3.9 to 110 µg kg⁻¹ for TAR, 14 to 67 µg kg⁻¹ for Lake Awassa, and 17 to 110 µg kg⁻¹ for Lake Ziway. It was found that the total mercury concentrations in all samples were below the United States Environmental Protection Agency guideline of 200 µg kg⁻¹.