Dhaka University Journal of Applied Science & Engineering

ZnS(Ag) was used to measure the gross alpha activity in drinking water of Old Dhaka, Dhaka District, Bangladesh. Screening was carried out for collected twenty samples; of which ten were tap water, five were ground water and the rest of five were bottled water samples. The gross alpha activity concentration was ranged from 0.84 + 0.06 to 14.40 + 0.23 mBq/L with an average activity of 6.52 + 0.18 mBq/L for tap water samples. For ground water samples, the gross alpha activity concentration was ranged from 0.87 + 0.18 to 1.46 + 0.48 mBq/L with an average activity of 1.22+ 0.63 mBq/L. The gross alpha activity concentrations were ranged from 5.07 +0.30 to 24.70 + 0.69 mBq/L with an average activity of 13.89 + 0.45 mBq/L for bottled water samples. The gross alpha activities for all cases were found below than the recommended value of 0.5 Bq/L or 500 mBq/L given by World Health Organization (WHO) in 2004. The annual effective doses for all cases were found below than the recommended value of 0.1 mSv/year given by International Commission on Radiological Protection (ICRP)

1. ref1