Radiological Risk Assessment of Drinking Water from Ignatius University Quarters, Rumuolumeni, Nigeria

Abstract

Aims: The aim of this study was to assess the level of natural radioactivity in drinking water (tap water) from Ignatius university staff quarters in order to determine the radiological health risks associated with consumption of such water. Study Design:  This study was purely an experimental work which involves collection of samples and laboratory analysis. Place and Duration of the Study: the study was carried out at Ignatius university staff quarters and some lecture halls within the institution between May 2018 and March 2019. Methodology: Twenty three (23) samples of drinkable water was collected from staff quarters and some lecture halls with 1.5 liters plastic containers which was rinsed thrice before collection. The samples were chemically treated by adding nitric acid and then pre-concentrated further by evaporating to certain levels. The residue were transferred to small cylindrical containers which were sealed and kept for 28 days in order to ensure secular equilibrium between 238u, 232th and their progenies and counted with sodium iodide activated with thallium detector. The results obtained were analyzed using some radiation models for radiological health risks.  Results: The measured activity concentration of natural radionuclides such as 40K, 226Ra and 232Th in drinking water were in the range of 4.14±3.61 to 48.30±3.88 Bql-1, bdl to 188.51±2.69 Bql-1 and bdl to 29.17±3.42 Bql-1 respectively. The mean values of 40K, 226Ra and 232Th are 18.79±4.24, 27.55±5.99 and 17.79 ±2.89 Bql-1 respectively which is higher than their respective recommended safe value. The estimated effective dose for different age groups  ranged from 0.073 to 317.58 mSvy-1 for infants, 0.050 to 78.05 mSvy-1 for children, 0.027 to 237.41 mSvy-1 for teenagers and 0.029 to 51.46 mSvy-1 for adults with mean values of  110.07, 25.92, 68.44 and 12.85 mSvy-1 respectively. The lifetime fatality cancer risk to adult estimated show that, approximately 19 out of 100 may suffer from some form of cancer fatality and 18 out of 1000 may suffer some hereditary effect. Conclusion: The result showed an elevated radioactivity level with its associated health risk. The populace might be at long term health risk if continuous exposure is maintained.