Abstract:
The concentrations of naturally occurring radionuclides 40K, 238U and 232Th in soil
samples collected across the town of Henties Bay in Western Namibia have been determined and used to estimate a baseline natural radiation level in the town. These concentrations were measured using an HPGe detector and found to vary from 790.2±31.6 Bq kg−1 to 1039.0±38.7 Bq kg−1 with a mean of 936.1±68.5 Bq kg−1 for 40K, 36.2±2.6 Bq kg−1 to 153.4±4.8 Bq kg−1 with a mean of 62.2±20.0 Bq kg−1 for 238U and 50.4±4.5 Bq kg−1 to 323.6±12.7 Bq kg−1 with a mean of 97.1±44.7 Bq kg−1 for 232Th. The corresponding effective dose rate obtained from the radionuclides is 0.16±0.04 mSv y−1. This dose rate is well below the limit of 1.0 mSv y−1 recommended for the public by the International Commission on Radiological Protection (ICRP) and indicates that the town has a normal background radiation.