NATURAL RADIONUCLIDES IN DRINKING WATER AVAILABLE IN SECONDARY SCHOOLS OF SOUTHERN PART OF DELTA STATE, NIGERIA

Abstract

Water is required by people of all ages. Therefore it is pertinent to be armed with basic knowledge to help in the evaluation of certain parameters required in the choice of the water consumed by people. This study employed gamma spectrometry using NaI (TI) detector to measure the activity concentrations of natural radioactivity in water samples available in some secondary schools
within the southern part of Delta State, Nigeria. To examine the radiological safety of the water samples in this study, committed annual effective dose was estimated for the age groups 12 – 17 years (students) and >17 years (teachers). A total of 30 samples of water were analyzed. Results obtained showed that the average activity concentrations of the samples of water ranged from 129.89 ± 11.37 - 256.60 ± 9.60 Bql–1, 5.39 ± 1.04 - 9.01 ± 1.87 Bql–1 and 1.60 ± 0.02 - 7.35 ± 1.87 Bql–1 for 40K, 238U and 232Th, respectively. The derived total combined annual effective dose received by the two groups was obtained as 7.60 mSvy–1 and 2.85 mSvy–1, respectively, with 238U having higher values than 40K and 232Th in all the samples in the order, 238U >40K >232Th.The values clearly exceeded the values recommended by regulating agencies like World Health Organization (WHO) with reference value of 0.1 and ICRP and IAEA with reference value of 1.0 indicating a state of radioactivity contamination. In  view of this, consumption of the water in the studied locations may pose a serious public health challenge, with the group 12 – 17 years being more susceptible