Abstract
Surface water from Miri Lake and groundwater from around Kadugli (West-Central Sudan) obtained by means of hand-pumps was analysed for U-238, Ra-226, Rn-222, and Th-232 activity concentrations. The surface water showed very low levels of radionuclide concentrations: < 1.0-7.5, 8.5-16.5, < 1.6, and <0.1-0.39 mBq L-1 for U-238, Ra-226, Rn-222, and Th-232, respectively. Groundwater revealed a significant amount of natural radioactivity (16.1-1720, 7.7-14.3, 3000-139,000, < 0.1-39 mBq L-1) respectively. The overall annual effective dose was below the WHO reference dose level of 0.1 mSv yr(-1) except in one groundwater sample with an associated dose of 0.7 mSv yr(-1). (C) 2008 IAEA. Published by Elsevier Ltd. All rights reserved.