الفهرس 
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Abstract
All building materials contain various amounts of natural
radioactive nuclides. So it is important for us to measure the
concentration of these radioactive nuclides to see if there is any
radiation hazards associated with using these materials in building
contracture or any other fields. The major radionuclides
responsible for the natural terrestrial background radiation are 40K
and the radioisotopes in the decay series of 238U and 232Th. In
order to estimate the concentration of these radioactive nuclides,
eighty four samples from forty one different quarries in Assiut
governorate Egypt, of four different kinds of row building
materials, as follow, Sand (twenty one quarry), Gravel (fifteen
quarry), Limestone (three quarries) and Clay (two quarries) were
collected. These particular materials were considered important
because they are usually used in construction of building materials
in Upper Egypt. Measurements were done by using gamma
spectrometry (NaI (Tl) 3” x 3”).
The mean activity concentrations of 226Ra, 232Th and 40K in sand samples were 4.74 ± 0.08, 4.10 ± 0.11 and 109.82 ± 1.14
BqKg-1, respectively, for gravel samples these values were 6.01 ±
0.15, 1.82 ± 0.11 and 31.60 ± 0.73 BqKg-1, respectively, but for
limestone samples these values are 4.77 ± 0.22,1.25 ± 0.11 and
13.80 ± 0.49 BqKg-1, respectively, And the highest values
observed are found in clay samples where the values are 13.19 ±
0.46, 10.20 ± 0.55 and 132.17 ± 3.06 BqKg-1, respectively. The
difference in the values for different samples indicate that, the specific activities of 238U, 232Th and 40K in raw building materials
and their products depend on geological and the geochemical
features of those materials. All of these values are smaller than the
worldwide average values reported by the UNSCEAR (2000).
Some radiation hazard indices like, Radium equivalent
(Raeq), Absorbed dose rate (D), External and Internal hazard
indices (Hex and Hin), Gamma index (Iγ), the indoor and outdoor
Annual Effective Dose Equivalent (AEDE), Excess Lifetime
Cancer Risk (ELCR) and the Annual Gonadal Dose Equivalent
(AGDE), were calculated, and found that these materials don’t
possess any radiological hazards for people in Assiut governorate
whom using these materials