The activity concentrations of primordial radionuclides
(40K, 226Ra and 232Th) in five
different types of commonly used building materials in southwest
Nigeria were measured using a low-background NaI(Tl) detector coupled
to an IBM-compatible multichannel analyzer. The highest mean concentration
of 40K, which was 887.5 ± 101.3 Bq.kg–1, was obtained
in gravel. Also, the highest mean concentrations of 226Ra
and 232Th were obtained, respectively, in sand and brick samples.
The lowest mean concentrations of 40K, 226Ra
and 232Th, respectively, were obtained in brick and cement
sample. The annual gonadal effective dose (AGED) and other radiological
parameters were estimated from the activity concentrations of the
radionuclides. The highest mean values of the AGED and radium equivalent
activity concentration obtained were 359.1 μSv.y–1 and
110.9 Bq.kg–1, respectively. All these radiological parameters
were below the maximum permissible levels recommended for safe use
of materials in building construction. It can therefore be concluded
that these materials do not pose any radiological hazard to the
dwellers of buildings constructed with them.