In this study, a well calibrated Super-Spec (RS-125) gamma spectrometer was used to measure the activity concentrations of 40K, 238U, 232Th and gamma doses rate at 1 m above the ground level over a granite mining field in Asa, Kwara State, North-central Nigeria. Measurements were carried out in 50 randomly selected sample points. The overall mean activity concentrations of 40K, 238U, 232Th and gamma dose are 570.91, 42.86, 18.15 Bqkg-1 , and 60.11 nGyh-1 respectively. The results of the activity concentrations were used to estimate the corresponding radiation hazard parameters to assess the suitability of the granite for building and construction purposes. The data in this study could serve as the baseline radiological data of the region for future references. •Activity concentrations of 40K,238U,232Th and gamma doses were measured over a granite mining field in Asa.•The total mean activity concentrations of the radioisotopes and gamma dose are 570.91, 42.86, 18.15 Bqkg-1 , and 60.11 nGyh-1 respectively.•The radiological hazards are higher than the recommended permissible limits.

Elevated radioactivity levels of ²²⁶Ra, ²³²Th, and ⁴⁰K in building materials were measured using gamma-ray spectrometry and their associated lifetime cancer risks were also determined. The mean activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K are 45.72 ± 0.55, 65.90 ± 8.89, and 487.32 ± 15.20 Bq kg⁻¹, respectively. Statistically, the principal component (PC) analysis indicates that higher loadings were recorded in Principal Component One (PC1) with large contribution from ²³²Th and ⁴⁰K. The leverage studies indicate that BN Ceramics (BNC) contributes more to the loadings in PC1 followed by Golden Crown Ceramic (GCC) sample. The mean values of 0.399 mSv y⁻¹ do not surpass the world average value of 0.7 mSv y⁻¹. The mean gamma index from the measured samples is 0.644, whereas a mean value of 0.271 for alpha index is noted in the samples. The activity utilization index (AUI) from the samples satisfied the AUI <2, which corresponded with the annual effective dose of <0.3 mSv y⁻¹, except interlock Site 2 and Gomez Spain tiles. Significantly, the mean value of excess lifetime cancer risk of 0.0014 is slightly lower than the world average value of 0.29 × 10⁻³.

Natural radioactivity measurement and dose assessment are important aspects of radiation protection. The goal of this study is to validate the previous results obtained from the in-situ measurements in the study area in order to ascertain the level of radiation hazards to the populaces living around the mining site.A3 × 3-inch lead-shielded NaI(Tl) detector was used to measure the activity concentrations of 40K,238U and232Thin soil, water and guinea corn grain samples collected from a granite mining field in Asa, Kwara State, North-central Nigeria. The overall mean activity concentrations of 40K,238U and 232Th are 441.06, 11.51 and 15.42 Bqkg−1for the soil samples, 20.67, 0.66, and 0.88 BqL−1 for the water samples and 214.31, 5.25 and 8.86 Bqkg−,1respectively for the grain samples. The bioaccumulation/transfer factors are 0.49, 0.46 and 0.58 for 40K,238U and 232Th respectively. The mean values of all the radiological hazard parameters are within the permissible limit recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation. Consequently, the risk of indoor and outdoor gamma radiation exposure is comparatively less for these Granite soils. Hence, the results in this study will reference future studies in terms of basic radiological data.

This work contains dataset of measured activity concentrations of 40K, 238U, 232Th and gamma doses at 1 m above the ground level over Beryllium and Gold mining fields in Ifelodun and Moro respectively, Kwara State, North-central Nigeria. A well calibrated Super-Spec (RS-125) gamma spectrometer was used to carry out these measurements. Measurements were carried out manually in 72 randomly selected sample points. Statistical analyses of the data were explored to infer potential statistical relationships. The obtained dataset is presented for further assessment that can offer insights into the safety state of Ifelodu, Moro and their environs from radiation protection point of view. The data in this study could serve as a substantial baseline radiological data of the region for future monitoring and epidemiology researches.

The activity concentration of ²³⁸U, ²³²Th and ⁴⁰K in the soils of mining and living areas of Ijero Ekiti were determined using hyper pure germanium gamma ray spectrometer. The mean concentrations of ²³⁸U, ²³²Th and ⁴⁰K were found to be 128.05 Bqkg⁻¹, 24.8 Bqkg⁻¹ and 455.05 Bqkg⁻¹, respectively, for mining areas, while it was found to be 42.02 Bqkg⁻¹, 43.27 Bqkg⁻¹ and 635.41 Bqkg⁻¹, respectively, for the living areas. The mean absorbed dose rate, annual effective dose equivalent, gamma index and the excess lifetime cancer risk evaluated for the locations were 89.70 nGyh⁻¹, 0.11 mSvy⁻¹ and 1.4 for mining areas; while it was 72.22 nGyh⁻¹, 0.089 mSvy⁻¹ and 1.14 for living areas, respectively. The absorbed dose rate, annual effective dose equivalent and gamma index estimated for the mining site were higher than the living areas. The mean excess lifetime cancer risk estimated for the mining areas was consecutively higher than the recommended limit of 0.29 × 10⁻³ for background radiation. It is therefore necessary for government to barn illegal mining activities going on in the town so as to reduce natural radiation burden from their operations in the town.

The natural radioactivity levels of soil samples collected from four local government areas in Kogi State, Nigeria were measured using a hyper-pure germanium detector, and the radiological hazard parameters associated with them were estimated. The measured concentration ranged from 7.82 ± 0.63 to 82.22 ± 1.99 Bq kg⁻¹ for ²³⁸U, 11.05 ± 1.10 to 114.86 ± 4.72 Bq kg⁻¹ for ²³²Th, and 3.38 ± 0.50 to 1272.20 ± 23.36 Bq kg⁻¹ for ⁴⁰K. Omala local government was found to have the highest concentrations of ²³⁸U (44.31 Bq kg⁻¹) and ²³²Th (52.13 Bq kg⁻¹), while Ajaokuta has the highest concentration of ⁴⁰K (711.72 Bq kg⁻¹). The lowest activity concentrations of ²³⁸U and ²³²Th were measured from soil samples collected from Ankpa local government area and ⁴⁰K from Dekina local government area. It was noted that the activity concentrations of ⁴⁰K were generally low for all the areas investigated except for Ajaokuta areas. The radium equivalents calculated for all the locations were observed to be lower than the radiation protection regulatory body reference value of 370 Bq kg⁻¹. The radiological parameters estimated for most of the locations compared well with world average values, except for Odogba-okaba, Salem University, Forest, Nepa, Gerugu, Niger Bridge, Igaliwu, Ijeke-ogane, Bagana, and Abegikolo villages, whose values exceeded the recommended limit. This may suggest that those living or working in these areas may be exposed to higher radiation burden from the natural radionuclides.