Author/Authors :
darwish, s. m. cairo university - faculty of science - physics department, egypt , khalifa, e. cairo university - faculty of science - physics departmentgiza, egypt , al-abyad, m. atomic energy authority - nuclear research centre - experimental nuclear physics department, cyclotron facility, Egypt , el-bahi, s. m. ainshams university - faculty of women for arts, science and education - physics department, Egypt
Abstract :
Using γ spectrometry, the concentration of the naturally occurring radionuclides 226 Ra, 232 Th and 40 K has been measured in cement and its raw materials which are used as building materials in Egypt. The radium equivalent activity (Raeq), indoor gamma absorbed dose rate (D R), annual effective dose (AEDR), alpha index (I α), gamma index (I γ), external radiation hazard index (H ex), internal radiation hazard index (H in), excess lifetime cancer risk (ELCR), annual gonadal dose equivalent (AGDE), emanation factor (F) and mass exhalation rate of radon (E Rn) associated with the natural radionuclides are calculated to assess the radiation hazard of the natural radioactivity in the building materials. The mean activity concentrations obtained for 238 U, 232 Th, 40 K in the raw materials of cement were 134.07, 35.97 and 403.48 Bq/kg, respectively and were 93.49, 29.64 and 257.90Bq/kg in final products of cement, respectively. The mean values for raw materials of Raeq , D R , AEDR, I α , I γ , Hex , H in , ELCR , AGDE, F and ERn were found to be 239.61 Bq/kg , 98.54 nGy/h , 0.12 mSv/yr , 0.79, 1.68, 0.65 mGy/yr , 1.07 mGy/yr, 0. 0.42×10^-3 , 0.76mSv/yr , 0.33 ,and 0.01 , respectively and for final products of cement were found to be 171.62 Bq/kg, 70.76 nGy/h,0.09 mSv/yr, 0.55, 1.2 , 0.47 mGy/yr , 0.76 mGy/yr , , 0.31×10^-3,0.54 mSv/yr , 0.26 and 0.01, respectively. From the analysis, it is found that these materials used for the construction of dwellings are safe for the inhabitants. The present results of concentration levels and radiation equivalent activities are compared with similar studies carried out in other countries.
