238U, 232Th content and radon exhalation rate in some Egyptian building materials

In controlling natural radiation exposure for the residents of dwellings, it is necessary to determine the levels of natural radioactivity (external exposure) and radon exhalation rate (internal exposure) from building materials. In this paper uranium (238U) and thorium (232Th) content were measured in different building material samples using two different techniques: first, using Jeol high resolution inductively coupled plasma mass spectrometer HR-ICP-MS (plasmax2); and, secondly, using solid state nuclear track detectors SSNTDs. There was a good agreement between the measurements of uranium and thorium with both methods. Exhalation rate and emanation coefficient of radon in several building material samples were determined using LR-115 polymeric nuclear track detectors. Radon exhalation rate varied from; 11.83 mBq m−2 h−1 in Red Clay Brick to 36.86 mBq m−2 h−1 in Granite. A series of equations were used to estimate indoor radon exposure and annual effective doses in some models typical room of Egyptian house.

► 238U and 232Th content in some building materials measured by HR-ICP-MS and SSNTD.
► Radon exhalation rate in some building materials were determined using LR-115.
► Analytical simulation applied to room models to evaluate radon absorbed dose rates.
► Comparing results obtained shows our study are consistent with the worldwide values.