Chemical and radiological risk assessment of uranium in borehole and well waters in the Odeda Area, Ogun State, Nigeria

Abstract

The activity concentrations of uranium in well and borehole water samples in the Odeda area were measured using gamma ray spectroscopic system. The results obtained were used to calculate human radiological risk over lifetime consumption by the population in the area. The activity concentrations of uranium in all the water supplies for drinking and domestic purposes were found to range from 0.51 ± 0.02 to 6.77 ± 0.23 Bq. l-1. The mass concentration was found to range from 20.17 ± 0.79 to 267.80 ± 9.09 µg.l-1. The radiological risks for cancer mortality risk were found to be low, typically ranging from 1.91 × 10-5 to 2.54 × 10-4, while that of the morbidity risk ranged from 2.93 × 10-5 to 3.89 × 10-4. However, the chemical toxicity was found to vary from 0.56 - 7.47 µg.kg-1.day-1 which is higher than the recommended acceptable safe level by various international organizations. Results of measurements could be of vital importance in radio-epidemiological assessment, diagnosis and prognosis of uranium induced diseases in the local population of the area under investigation. Key words: Uranium, radiological risk, toxicity risk, cancer mortality and morbidity risk.