Assessment of Natural Radioactivity Levels and Radiological Significance of Bottled Drinking Water in Bangladesh

This study deals with the assessment of natural radioactivity due to 226Ra, 232Th and 40K in bottled drinking water samples, marketed in Bangladesh. High purity germanium (HPGe) detector based spectrometry system coupled with Multi Channel Analyzer (MCA) was used to obtain gamma-ray spectra. The mean concentrations of 226Ra, 232Th and 40K were found to be 3.28±2.10, 6.40±2.92 and 18.26±17.49 Bq.L-1 respectively. The committed effective doses due to ingestion of natural radionuclides from the consumption of bottled water for four different age groups were estimated. The annual cumulative effective doses due to all three natural radionuclides for different age groups of children (2–7 y), 7–12 y, 12–17 y and adults (>17 y) were estimated to be 1.54, 2.07, 3.41 and 1.83 mSv y-1 respectively. Among the three natural radionuclides, annual effective doses due to intake of 226Ra for age groups 7-12 y and 12-17y are significant. For children (2-7 y) and adults (>17 y), annual effective doses due to intake of 232Th are significant. The obtained results are compared with the reported and recommended values from other countries and international organizations respectively. However, annual estimated effective doses for all four age groups from the intake of natural radionuclides in bottled drinking water were higher than the World Health Organisation (WHO) recommended limit of 0.10 mSvy-1 as well as the average radiation dose of 0.29 mSvy-1 received per head worldwide due to ingestion of natural radionuclides assessed by UNSCEAR -2000.