Gamma-ray measurements of natural radioactivity in cultivated and reclaimed soil, Upper Egypt

Specific activity of primordial radionuclides in soil samples from 10 different regions in Qena governorate and Wadi EL-Lagita were determined by gamma-ray spectrometry. A total of 50 soil samples were collected from different sorts of soil with depth ranged from 0- 25 cm. The energy peaks used were: 352.0 keV of 214Pb and 609.3, 1120.3 and 1764.5 keV of 214Bi for 226 Ra. In the case of 232Th the energy peaks used were: 238.6 keV of 212Pb, 2615 of 208Tl and 911.1 keV of 228Ac. While the radioactivity of 40K was obtained from the single photopeak of this isotope at 1460.75 keV. The total uncertainty of the obtained values of the radioactivity was calculated from the systematic and the random error of the measurements. Concentrations of radionuclides in soils analyzed in this study ranged from 7.9±2.8 to 96.1±9.8 for 226Ra, 8±2.8 to 19 ±4.4 for 232Th and 85.2±9.2 to 302.5±17.4 Bq/kg for 40K.The results obtained were compared with those from other studies in the world and Egypt. The radiological health implication to the population that may result from these values is found to be low and almost insignificant, except in one case. No artificial radionuclide, however, was detected in any of the samples, hence, measurements have been taken as representing baseline values of these radionuclides in the soil in studying areas. Key words: Natural radionuclides, under reclamation, reclaimed and cultivated soil