Mapping of Uranium-238 Deposit and its Contribution to Indoor Radon Gas in Ota, Ogun State, Nigeria

Abstract

In the present study, the distribution of uranium-238 was mapped from the background radiation of the area of study in order to determine its contribution to the concentration of indoor radon. The background radiation was studied using the handheld gamma spectrometer (RS 125) while the indoor radon concentration was measured with a Durridge RAD7 instrument. The results obtained showed variation in the distribution of 238U, 232Th and 40K in the study area with values ranging between 17.9 ± 0.3 and 58.05 ± 0.3, 2848 ± 10541 ± 0.8 and 3.25 ± 0.2 and 11.48 Bq/kg respectively. Furthermore, the indoor radon concentration was determined for the office on the ground floor, the result obtained was noted to be between 20 and 160 Bqm-3 which is far higher than the result obtained for the office on the first floor which is BDL-19 Bqm-3. In each cases, the results are lower than the international recommended safe limit of 200 Bqm-3. Therefore, it can be concluded that the background radiation from the soil in the premises and under the building contributes to the high concentration of indoor radiation in the office.