Radiological assessment of drinking water of the Chittagong region of Bangladesh

The specific activity of Rn-222, Ra-226, Th-232 and K-40 in drinking water of the Chittagong region of Bangladesh was measured using high resolution gamma spectrometry. The specific activity of Rn-222 in the drinking water ranged from 2.04 +/- 0.51 to 9.39 +/- 2.06 Bq.l(-1) and the mean activity was 4.46 +/- 1.95 Bq.l(-1). The mean specific activity of Ra-226 was found to be 0.043 +/- 0.017 Bq.l(-1), the mean activity of Th-232 was 0.19 +/- 0.05 Bq.l(-1), and the mean K-40 activity was 4.16 +/- 1.58 Bq.l(-1). No Cs-134 and Cs-137 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 mu Sv.y(-1) for Th-232, 7.6 mu Sv.y(-1) for Ra-226 and 16.7 mu Sv.y(-1) for K-40.