Background: The existence of some
radionuclides in soil and some building materials
produce a β-γ radiation field, which in some regions
the exposure of these radionuclides to human is high.
Materials and Methods: The air-absorbed dose,
indoor and outdoor annual effective dose of soil and
some building material samples (ceramic, granite,
gypsum, etc.). The samples were collected from 35
different regions in the northwest of Iran were
calculated. Specific activity of natural radionuclides
226Ra, 232Th and 40K were measured by using a β-γ
spectrometer consisted of NaI(Tl) and organic scintillators.
The analysis of measured spectra was based
on maximum likelihood estimation. The calculated
data were compared with world's mean values.
Results: It is found that the specific activity of 40K
ranges from 573.8 to 1392 Bqkg-1, for 232Th ranges
from 6 to 54.6 Bqkg-1 and for 226Ra ranges from and
5.1 to 36.2 Bqkg-1. In some regions, the
concentrations of natural radionuclides (40K, 232Th,
226Ra) were higher than standard level. Conclusion:
Experimental results related to specific activity,
indoor and outdoor annual effective doses of 226Ra,
232Th and 40K revealed that radionuclide
concentration in soil and some building material
samples of some regions of northwest of Iran are of
some radiological importance. Iran. J. Radiat. Res.,
2011 8(4): 237-242
Ashrafi S, Alaei S. Measuring γ–ray dose of terrestrial samples using β-γ Spectrometry. Int J Radiat Res 2011; 8 (4) :237-242 URL: http://ijrr.com/article-1-686-en.html