Assessment of radiation risk and radon exhalation rate for granite used in the construction industry

Health Hazards Assessment and Geochemistry of ElSibai-Abu ElTiyur Granites, Central Eastern Desert, Egypt

“…Estimation of the excess absorbed gamma dose rate indoors caused by building materials (increment to that of outdoors) relies essentially upon: (1) the concentrations of the radioisotopes ( 238 U, 232 Th, and 40 K), (2) the properties of these materials, and (3) design ways in dwellings [64]. As indicated by the European Commission [20], the extra AGDR (in nGy h −1 ) in the air within a room, owing to using the granite as superficial construction materials in its walls and floor, can be determined using the Equation (6) [28,65]: AGDR nGy h −1 = 0.12AC Ra + 0.14AC Th + 0.0096AC K (6) Notably, the coefficients 0.12, 0.14, and 0.0096 in nGy h −1 /Bq/kg included in Equation ( 6) are estimated according to the model of the standard room dimension (4 m × 5m × 2.8 m) designed by rectangular walls of concrete (20 cm in thickness and 2350 kg/m −3 in density) and tiled with superficial material (3 cm thickness and 2600 kg/m 3 density) in walls and floor.…”

“…radioisotopes ( 238 U, 232 Th, and 40 K), (2) the properties of these materials, ways in dwellings [64]. As indicated by the European Commission Europe [20], the extra AGDR (in nGy h −1 ) in the air within a room, owing to usin superficial construction materials in its walls and floor, can be determined tion (6) [28,65]:…”

“…Evaluation of radon exhalation rate (RER), in building materials, and determining the resulting indoor radon concentration [70] is vital. As per the European Commission European Commission [20] for a model of a standard room of dimensions 4 m × 5 m × 2.8 m tiled with granitic slabs of 3 cm thickness (2600 kg/m 3 density) in its walls and floor, and depending on the 226 Ra concentration (AC Ra ), the following equation gives theoretically radon exhalation rate RER in Bq m −2 h −1 as described [28,71]:…”

“…where λ (=0.0076/ h) is the 226 Ra decay constant and ρ (=2600 kg/m 3 ), η (=0.45) and d (=0.03 m) are the density, emanation coefficient, and thickness of granite slab used in tiling the room, respectively [28]. Table 4 shows the mean value (5.17 ± 0.45 Bq m −2 h −1 ) and range (2.25 to 9.6 Bq m −2 h −1 ) of RER from ElSibai-Abu ElTiyur granites.…”

“…According to the theoretical evaluation of radon exhalation rate in Equation ( 9), the indoor radon concentration (IRC) in Bq/m 3 was calculated as follows [28,63]:…”