Radiological Assessment of Drinking Water of the Chittagong Region of Bangladesh

The specific activity of 222Rn, 226Ra, 232Th and 40K in drinking water of the Chittagong region of Bangladesh was measured using high resolution ? spectrometry. The specific activity of 222Rn in the drinking water ranged from 2.04 ± 0.51 to 9.39 ± 2.06 Bq.1-1 and the mean activity was 4.46 ± 1.95 Bq.1-1. The mean specific activity of 226Ra was found to be 0.043 ± 0.017 Bq.1-1, the mean activity of 232Th was 0.19 ± 0.05 Bq.1-1, and the mean 40K activity was 4.16 ± 1.58 Bq.1-1. No 134Cs and 137Cs activity was detected in any of the samples of drinking water from the region. From these data the age-dependent associated effective doses due to the ingestion of these isotopes as a consequence of direct consumption of drinking water has been calculated. The average adult effective dose due to intake of drinking water was 56.2 µSv.y-1 for 232Th, 7.6 µSv.y-1 for 226Ra and 16.7 µSv.y-1 for 40K.