Estimation of Residents Exposure Risks to Radiological Parameters in Some Building Materials in Nigeria

Some of the brands of tiles commonly available in the markets in Nigeria, which are used for building purposes, were analysed in order to estimate the concentration of naturally occurring radionuclides. The analysis was done with the aid of High-Purity Germanium (HPGe) detector. The results revealed that the average activity concentrations in the sample of tiles, cement and sand varied from 41 ± 4 to 96 ± 8.3, 27 ± 9.5 to 76.5 ± 2.5 and 140 ± 7.9 to 940 ± 19.2 Bqkg⁻¹ for ²³²Th, ²²⁶Ra and ⁴⁰K, respectively. The results obtained were used to determine the impact of these building materials on users. The radium equivalent activity (Ra_eq) ranged between 125 – 280 Bqkg⁻¹ and were observed to be lower than 370 Bqkg⁻¹ in all the samples tested, which is the recommended safe limit. Similarly, the absorbed dose rates were noted to vary from 51.00 – 122.52 nGyh⁻¹. However, one of the samples examined showed a result of 122.52 nGyh⁻ for the indoor absorbed dose rate (D_R), which is higher than the internationally recommended safe value of 80 nGyh⁻¹according to USEPA. The results revealed that the building materials investigated do not pose any danger to the end users.