Natural radioactive nuclides and chemical components in the groundwater of Beni SuefGovernate, Middle Egypt

Abstract

Measurements of natural radioactivity in drinking water have been performed in manyparts of the world, mostly for assessment of the doses and risk resulting from consumingwater. A study of the radionuclide and chemical components in groundwater from BeniSuef Governate, Egypt has been carried out. Fifty water samples were analysed byγ-ray spectroscopyto determine the 226Ra, 232Th and 40K concentrations; major elements, pH, alkalinity and conductivity werealso measured. The activity concentration values ranged from 0.008 to0.040 Bq l−1 for226Ra, from 0.003to 0.019 Bq l−1 for232Th and from0.025 to 0.344 Bq l−1 for 40K. Theannual ingestion of these radionuclides, using local consumption rates (averaged over the whole population) of1.5 l d−1, was estimated tobe 8.59, 4.86 and 83.47 Bq y−1 for 226Ra, 232Th and 40K, respectively. The estimated effective doses from drinking water were found to be2.4 µSv y−1 (226Ra), 1.1 µSv y−1 (232Th)and 0.5 µSv y−1 (40K). The contribution of these radionuclides to the committed effective dose from a year’sconsumption of drinking water is therefore estimated to be only 4% of the WHO value(0.1 mSv y−1). The moderate pH value is the most important parameter, and there was no observedcorrelation between natural radioactivity and electrical conductivity or concentrations ofmajor ions.