Assessment of Radon Concentration of Ground Water in Ijero Ekiti

Abstract

Assessment of radon concentration in ground water in Ijero, Ekiti State, was carried out using the RAD7/RAD H20 driven alpha spectrometry technique. The results were used to estimate the annual effective committed doses in order to establish possible radiological health hazards and to suggest necessary safety measures Forty water samples from boreholes, wells, and streams were collected and analyzed for the radon concentration. The minimum and maximum radon concentrations in the samples were 0.168 Bq/L and 78.509 Bq/L from stream and borehole samples, respectively. Out of the samples, 18 had radon concentration exceeding 11.1 Bq/L, the maximum permissible limit. It was observed that none of the samples has radon concentration value up to 100 Bq/L, which is recommended by the European Union to be the upper bound value, above which remedial action is required. No particular trend was observed, and no relationship can be inferred to exist between the mean radon concentration, temperature, and PH of the samples. None of the samples had an annual effective dose higher than the maximum permissible limit of 0.2 mSv/y if consumed by children and 0.1 mSv/y if consumed by adults. We concluded that two-mica-granite geological structures and the depth of the source area predominant factor for high radon concentration and definitely contributed to the level observed in the borehole sources. The relatively high levels of radon indicate a certain level of health risk. Though the effective dose seemed low, effects of prolonged exposure to radiation is still possible