Investigation of natural radioactivity levels in water around Kadugli, Sudan

Surface water from Miri Lake and groundwater from around Kadugli (West-Central Sudan) obtained by means of hand-pumps was analysed for 238U, 226Ra, 222Rn, and 232Th 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 238U, 226Ra, 222Rn, and 232Th, 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.