TITLE:
Radiological Hazards for Marble and Granite Used at Shak El Thouban Industrial Zone in Egypt
AUTHORS:
Amany T. Sroor, Saher M. Darwish, Samia M. El-Bahi, Mohamed G. Abdel Karim
KEYWORDS:
Radiological Hazards; Marble; Granite; HPGe Detector; Shak El Thouban
JOURNAL NAME:
Journal of Environmental Protection,
Vol.4 No.12A,
December
24,
2013
ABSTRACT:
The background level of radiation in
the natural environment surrounds us at all times. Levels of natural occurring
radioactivity in marble and granite used at Shak El Thouban industrial zone in
Cairo, Egypt have been investigated using HPGe detector through gamma-ray
spectrometry. The activity concentration of radionuclides in the 238U-, 232Th-series and 40K has been determined. The average
activity concentration of 238U, 232Th and 40K
for marble samples was 23.77 Bq/kg ranged from (10.91 to 45.4), 10.75 Bq/kg ranged from (5.46 to
23.61) and 520.43 Bq/kg ranged from (382.30 to 1132.41), respectively. The 238U, 232Th and 40K activity concentration for granite samples
were 54.31 Bq/kg ranged from (12.04 to 106.34), 113.57 Bq/kg ranged from (23.91
to 270.36) and 7867.51 Bq/kg ranged from (2017.60 to 11436.91), respectively.
Concerning the radiological risk, the radium equivalent activity, external and
internal radiation hazard indices, the radiation level index and absorbed dose
rate were evaluated. The mass exhalation rates of 222Rn and
emanation coefficient have been also calculated. The mass exhalation rate of
radon was found to be from
14.86 to 137.13 and 16.48 to 155.26 μBq/kg·s for marble
and granite samples, respectively. The mean values of the specific activity of 226Ra,
activity of 238U before and after sealing time and the mass
exhalation rate of radon for granite samples are twice that for marble samples.
All radiological indices and the mass exhalation rate of radon are lower than
the permissible levels for building material in all marble samples, while all
granite samples are higher and unsafe and pose a risk to the workers and users
of these products due to the emanation of radon that may accumulate by time,
especially in closed spaces.