Assessment of Radiological Hazard Indices of Building Materials in Ogbomoso, South-West Nigeria

This research study aims at assessing the radiological hazards indices of materials used for the construction of Ladoke Akintola University of Technology Teaching Hospital, a tertiary medical facility in Ogbomoso, South-West, Nigeria. The determination was sequel to the measurement of the radionuclide contents of the materials (Granite, Cement, Sand, and Concrete) used in the construction of the building, using a high-purity germanium detector gamma spectrometer. The natural radionuclides detected are traceable to the primordial series of 238U and 232Th as well as 40K and traces of globally released 137Cs. The specific activity values ranged between 27.79 and 30.65 Bq kg-1 with a mean of 29.22 Bq kg-1 for 238U; while for 232Th, the range was 16.69-22.73 Bq kg-1 with a mean of 19.71 Bq kg-1. Relatively higher specific activity values were recorded in 40K with a range of 132.76-276.42 Bq kg-1, while the mean was 204.59 Bq kg-1. However, a relatively low-specific radioactivity was obtained from 137Cs with a range of 1.03-14.90 Bq kg-1 and a mean of 13.32 Bq kg-1. All other values of other indicators were below the maximum permissible limit (MPL). The determination carried out prior to the building being occupied, showed no evidence of artificial radionuclide. Hence, the building materials may be considered safe for building construction and the values measured can therefore serve as reference for future measurement.