TITLE:
Radiological Hazard Assessment of Raw Granites from Ranyah, KSA
AUTHORS:
Sadek Zeghib, Abdulkadir Sh. Aydarous, Ali Al-Qahtany
KEYWORDS:
Environmental Radioactivity, Gamma Spectrometry, Activity Concentration, Radon, Granite
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.4 No.9,
September
19,
2016
ABSTRACT: The assessment of radiological hazard due to external and internal indoor
exposure was investigated for 26 raw granites collected from different granite
quarries in Ranyah (KSA). The activity concentrations of 226Ra, 232Th
and 40K were measured by high-resolution gamma spectrometry. Four
granites were classified as “anomalous” due to their relatively high
radioactivity. The averages and ranges of their activity concentrations were
667 (305 - 1120), 320 (161 - 491) and 586 (282 - 893) Bq·kg-1, respectively.
The corresponding ones for all remaining 22 granites were 45 (18 - 77), 39 (16
- 73) and 1178 (954 - 1531) Bq·kg-1,
respectively. In accordance with new European Basic Safety Standards (BSS)
directives requiring a uniform reference level for indoor external exposure to
gamma rays of 1 mSv·y-1, all 22
granites may be used as bulk or ornamental building materials without any
restrictions. Three
anomalous granites should be subjected to control to be used as bulk materials.
One anomalous granite was categorized as hazardous having an activity
concentration index higher than 6. All four anomalous granites exceeded the level of newly adopted reference
level of 300 Bq·m-3 for radon indoor exposure in case of poor ventilation. Two of them exceeded even
for adequate ventilation.
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