The natural radioactivity of soil samples from
Assiut city, Egypt, was studied. The activity concentrations
of 28 samples were measured with a NaI(Tl) detector. The
radioactivity concentrations of 226Ra, 232Th, and 40K
showed large variations, so the results were classified into
two groups (A and B) to facilitate the interpretation of the
results. Group A represents samples collected from different
locations in Assiut and characterized by low activity concentrations
with average values of 46.15±9.69, 30.57±4.90,
and 553.14±23.19 for 226Ra, 232Th, and 40K, respectively.
Group B represents samples mainly collected from the area
around Assiut Thermal Power Plant and characterized by very
high activity concentrations with average values of 3,803±145,
1,782±98, and 1,377±78 for 226Ra, 232Th, and 40K, respectively.
In order to evaluate the radiological hazard of the natural
radioactivity, the radium equivalent activity (Raeq), the
absorbed dose rate (D), the annual effective dose rate (E), the
external hazard index (Hex), and the annual gonadal dose
equivalent (AGDE) have been calculated and compared with
the internationally approved values. For group A, the calculated
averages of these parameters are in good agreement
with the international recommended values except
for the absorbed dose rate and the AGDE values which
are slightly higher than the international recommended
values. However, for group B, all obtained averages of
these parameters are much higher by several orders of
magnitude than the international recommended values.
The present work provides a background of radioactivity
concentrations in the soil of Assiut.