Evaluation of Chemical and Radiological Impacts of Radionuclides in Borehole Waters in Igbajo Town, Osun State, Nigeria

Abstract

Abstract Water is a universal solvent on earth and sources such as wells, rivers, springs, boreholes, and other freshwater bodies typically serve as a pathway for contaminants to enter the ecosystem while also supplying water for domestic and drinking purposes. The activity concentrations of radionuclides in borehole water in Igbajo town were assessed using gamma-ray spectroscopy, so as to effectively determine the degree of radiological risk to the environment and its inhabitants, the outcomes were used to calculate all the radiological impact parameters. The activity concentrations obtained for 40 K, 238 U and 232 Th ranged from 7.25 ± 0.60 to 62.15 ± 4.48 Bq.L –1 ; 3.08 ± 0.45 to 15.24 ± 3.07 Bq.L –1 and 1.08 ± 1.10 to 17.75 ± 1.59 Bq.L –1 and with average values of 23.12 ± 1.59 Bq.L –1 , 6.27 ± 2.01 Bq.L –1 and 7.01 ± 0.89 Bq.L –1 respectively. The Annual Effective Dose (AED) for ingested radionuclide in drinking water for an adult was 1.4872 µSv.yr –1 . The Radium Equivalent Activity Index, Ra eq obtained was 34.9186 Bq.L –1 . The estimated hazard indices H int and H ext were 0.04876 and 0.06574 respectively. The Excess Lifetime Cancer Risk, ELCR (x10 –6 ) was 5205.15. With a lifetime expectancy of 70 years, this high value suggests that there is a high chance of developing cancer. The value of the Annual Gonadal Equivalent Dose, AGED in the water was 55.9175 µSv.yr –1 . The estimated Gamma Index, I γ was 0.1273 mSv.yr –1 . There is a significant health hazard to the environment and people living in the area owing to the radioactivity contents and radiological impact parameters.