Natural radioactivity of ground and hot spring water in some areas in Yemen

Water from bedrock frequently contains higher concentrations of natural radionuclides than water from other sources. Groundwater from Assalamia-Alhomira and Juban areas (southeast of Sana'a) and hot spring water from Dempt area (south Sana'a) in Yemen were analyzed for Ra-226, Th-232 and K-40 activity concentrations. The average activity concentrations for groundwater from Assalamia-Alhomira area were 4.04 Bql(-1) and 1.81 Bql(-1) for Ra-226 and Th-232, respectively, while 40K was not detectable, while that for groundwater samples from Juban area were 2.95 Bql(-1), 0.72 Bql(-1) and 34.9 Bql(-1) for Ra-226, Th-232 and K-40, respectively. On the other hand, the activity concentrations for hot spring water from Dempt area were 3.48 Bql(-1), 1.01 Bql(-1) and 16.05 Bql(-1) for 226R a, 232 a Th and 4 K, respectively. Also annual effective dose equivalent of ingestion of these waters was calculated. The results showed that the annual dose equivalent obtained in the present study was much higher than the recommended value (0.1 mSv year(-1)) as reported by WHO. The results were compared with those for drinking water. (C) 2011 Elsevier B.V. All rights reserved.