The radiological hazard of building materials originating from clay, rock
and other mineral wastes has attracted more attention because they contain
natural radionuclides (226Ra, 232Th, and 40K). The activity concentration of
radionuclides in red-clay brick samples obtained from three different
brickyards in Shangluo, China waHs measured. Various indexes, including
radium equivalent activities, Raeq, external hazard index, Hex, internal
hazard index, Hin, indoor air absorbed dose rate, D, and annual effective
dose, AED, of the aforementioned radionuclides in the bricks were used to
assess the radiation hazard for people. The average activity
concentrations of 226Ra, 232Th, and 40K were respectively 34.5 ? 1.9, 62.5 ?
2.1, and 713.7 ? 19.8 Bqkg?1 for the studied red-clay bricks. The Raeq
values of the red-clay brick samples varied from 167.0 to 184.7 Bqkg?1,
which are lower than the limit of 370 Bqkg?1. Moreover, the activity
concentrations of natural radionuclides in unfired brick, clay and coal were
also determined and the results were compared with that in the red-clay
brick samples. This study shows that the red-clay bricks produced in
Shangluo, China can be used safely in construction industries.