Radionuclide analysis of drinking water in selected secondary schools of Epe local government area, Lagos state, Nigeria

Abstract

A total number of 20 water samples were collected from different locations, spreading over selected twenty public secondary schools in the Local government area of Epe in South Western, Nigeria. Ten well water samples were collected from selected rural school area and ten borehole water samples in urban schools area. The concentrations of natural radionuclides were determined using gamma ray spectrometer comprising a 7.6 cm x 7.6 cm Nal (TI) detector coupled to a multichannel analyser for spectral analysis. Data were analysed using descriptive statistics. The activity concentrations from boreholes and wells with depths ranging between 17.68 and 38.1 metres were randomly sampled and determined from 20 locations in public schools in Epe LGA. The activity concentration obtained were in the ranges of (38.3 – 292.8) Bq/L with mean value of 13.4 + 10.8 Bq/L for ⁴⁰K, 1.2 – 36.7 Bq/L with mean value of 6 + 1.4 Bq/L for ²³⁸U and 1.2 – 11.7 Bq/L with mean value of 4.5 + 1.2) Bq/L for ²³²Th. The values obtained for the mean activity concentrations for the radionuclides from the 20 boreholes and well water samples in Epe, revealed that ⁴⁰K, ²³⁸U and ²³²Th values were below the United Nations Scientific Committee on the Effects of Atomic Radiation recommended international limits of 370Bq/L and within the tolerance level indicating minimal radiological health burden.

Keywords: Borehole water, Epe, Health hazard, Natural radionuclide, Secondary school, Well water.