238U, 232Th, 226Ra, and 40K radioactivities were determined in commercial granite samples collected
from local market using a NaI (Tl) gamma-ray spectroscopy system. 238 U, 232Th, 226 Ra, and 40 K activity
concentrations of the studied commercial granites range between 31 and 351.33 BqKg-1, 22.2 to 102.35
BqKg-1, 22.2 to168.35 BqKg-1 and 881.49 to 1460.67 BqKg-1, respectively. The highest values of activity
concentrations of 238U, 226Ra and 40K were recorded in Lahm Mafroum commercial granites. High
radioactivity of Lahm Mafroum is attributed to the presence of meta-autonite, zircon, allanite, monazite,
sphene and apatite.
Absorbed Dose Rate (D), annual effective dose equivalent (AEDE), radium equivalent activity (Raeq),
external (Hex) and internal (Hin) hazard index, in addition to activity gamma index (I!) caused by gamma
emitting natural radionuclide are determined from the obtained values of 226Ra, 232Th and 40K. Fairly, many
of the studied commercial granites do not satisfy the universal standards.