Dataset on radioactivity measurement of Beryllium mining field in Ifelodun and gold mining field in Moro, Kwara State, North-central Nigeria

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.


Specifications
Physics and Astronomy Specific subject area Radiation Type of data Table; Figure  How data wereacquired Super SPEC RS-125 spectrometer with large 2.0 × 2.0 NaI crystal was used to the radioactivity measurements. The coordinate and elevation were determined using a global positioning system (GPSMAP78) Data format Raw analysed Parameters for data collection The measurement of the activity concentration of the radionuclides was carried out at about 1 metre above the topsoil. Description of data collection Four (4) readings were recorded at each data point at the interval of 120 s. 72 sample points were recorded in total to cover the two mining fields. The field was divided into grids of approximately equal size, with each box representing a data collection point. At each of these samples location, the coordinate and elevation were determined using a global positioning system (GPSMAP78) Data source location Ifelodun and Moro Local Government Area (L.G.A.), Kwara State, North-central Nigeria.
The study area for the data acquisition is bounded by longitude 4.759166 °E and latitude 8.435183 °N and longitude 4.460320 °E and latitude 8.965820 °N Data accessibility All the data are in this data article Value of the data • The data in this work are useful because they provide useable information on the concentrations level of activity concentrations of 40 K, 238 U, 232 Th and gamma dose, which could be used to evaluate the degree of ionizing radiation exposure and probable radiological impacts within Ifelodun, Moro and their environs. • The dataset could be used to compute the radiological impact parameters such as the absorbed dose rate, annual effective dose, external and internal radiation hazard indices and excess life time cancer risk due to the concentration of natural radionuclides in the samples. Radiological risks assessment and health implications could also be estimated by comparing them with the international recommended limits. • The radioactivity measurements can be repeated in mining sites in the neighboring locations such as Asa, Ekiti, Patigi and other Local Government Areas (LGA). This radiometric survey can also be extended to cover all the mining sites in the whole of Kwara state. • The dataset in this work is useful for educational purposes in health and radiation Physics i.e. in applications of gamma spectrometry methods and environmental radioactivity.The dataset could also be used by the Nigerian Environmental Protection Agency (NEPA) and other regulatory bodies for monitoring and assessment of radiological implication of mining activities so as to implement specific statutory requirements and laws to regulate the mining activities in the country. Similar works can be found in [1][2][3][4][5][6] .

Data description
The dataset covers the measured concentration levels of activity concentrations of 40 K, 238 U, 232 Th and gamma dose rate for Beryllium and Gold mining locations in Ifelodun and Moro LGAs respectively, in Kwara State, North-central Nigeria. The measured activity concentration of these natural radionuclides considered and their geographical coordinatesis given in Tables 1 and 3 . Additionally, descriptive statistical analyses were carried out on the raw dataset to comprehend the statistical distribution of the measurements. The statistical summary of the dataset is presented in Tables 2 and 4 . The correlation analysis was conducted as shown in Tables 5 and 6 to study the relationship between these measured radionuclides and the gamma dose rate.
The unceasing release of mining waste and tailings into the biosphere from mining activities has been reported to bring about building-up of radionuclides in soil, air, water and the food chain. According to [ 7 -9 ] report, the recommended values for general populace for exposure to 40 K, 238 U, 232 Th and DR are given as 420.0 0, 32.0 0, 45.0 0 Bq kg −1 and 59.0 0 nGy h −1 , respectively. When the levels of the activity concentrations of these aforementioned radionuclides and the gamma doserate exceeds these minimum permissible limits, it can cause severe health effects like cancer and other radiation health effects, damaging critical organs of the body which could even lead to death [ 3 -5 , 9-11 ].

Study area
The study areas are in Ifelodun and Moro LGAs of Kwara state, Nigeria. It is situated between latitudes 8 °20 N and 8 °50 N and Longitudes 4 °25 E and 4 °65 E ( Fig. 1 ). Kwara is located in the North-central part of Nigeria with a tropical wet and dry climate with average yearly rainfall of about 1200 mm [12] . Its mean annual temperature is about 26.2 °C; which peaks at about 30 °C in the month of March. Wet season is generally experienced between April and October and dry season between November and March. For the geology of the study area, a large part of Kwarais underlain by basement complex rock. The soils are formed from basement complex rocks (metamorphic and igneous rocks) which is about 95%. The metamorphic rocks consist of biotitegnesiss, banded gnesiss, quartzite augitegnesiss and granitic gnesiss. The intrusive rock comprises of pegmatite and vein quartz [12][13][14][15] . The assortment of basement complex rocks brings about large number of ferruginous groups of soils. Therefore, lateritic soil type (generally deep red in colour with high clay content) is the major type of soil in Ilorin. Detail geology of Ilorin can be found in [12][13][14][15] .

Field survey
Measurements of activity concentrations of 40 K, 232 Th, 238 U and the radiation dose exposures were carried in-situ using Super SPEC RS-125 spectrometer with large 2.0 × 2.0 NaIcrystal. The measurement of the activity concentration of the natural radionuclides and the gamma dose rate was carried out at about 1 metre above the ground [ 2 , 3 , 6 ]. The Super Spec (RS-125) gamma spectrometer is a portable handheld radiation detector with high precision and probable error of about 5%. It offersbetter integrated design with largedetector,decent sensitivity and it is easy to use. The model RS-125 super-spec is manufactured by Canadian Geophysical Institute, Canada. It comes with a big data storage which allows measurement of multiple readings. The Super Spec spectrometer was calibrated in accordance with Canadian Geophysical Institute. The calibration was carried out on 1 × 1 m test pads, which uses 5 min spectra accumulation on uranium, thorium and potassium pads and 10 min accumulation on the Background pad. It uses sodiumiodide (NaI) crystal which is doped with thallium [Tl] as activator. The instrument's energy range is from 30 to 30 0 0 keV, which is sufficient to detect most of the radiation giving off from the terrestrial sources (i.e. 214 Bi (609.31 and 1764.49 keV) gamma rays to determine 238 U, 212 Pb (238.63 keV), 208 Tl (583.19 keV) and 228 Ac (911.21 keV) gamma rays to determine 232 Th and the photopeaks of 40 K which occours in the background spectrum at 1460.83 keV). The total Table 4 Statistical summary of the measured activity concentrations of the natural radionuclides and the gamma dose rate of Beryllium mining field in Ifelodun LGA.  Table 5 Pearson's correlation matrix showing the relationship between the measured radionuclides and the gamma dose rate at Beryllium mine field in Ifelodun LGA. count of 120 s per assay was employed for best accuracy as stated in Radiation Solutions Inc [ 2 , 3 , 16 ]. The assay mode of the instrument gives the activity concentration of 40 K in percentage (%), 238 U and 232 Th in part per million (ppm). The data was converted to the conventional unit Bqkg −1 using conversion factors given by [ 8 , 9 , 17 , 18 ]. In this work, four (4) readings were recorded at each data point at the interval of 120 s. 72 sample points were recorded in total to cover the two mining fields. The field was divided into grids of approximately equal size, with each box representing a data collection point. At each of these samples location, the coordinate and elevation were determined using a global positioning system (GPSMAP78). More details about the instrument can be found in earlier works where this Super SPEC RS-125spectrometer was used [ 2 , 3 , 6 , 18 , 19 ].

Descriptive statistics
The detailed statistical descriptions of the results of the in-situ gamma spectrometry measurements using Super-Spec RS125 is presented in Tables 2 and 4 . It shows their estimated minimum, maximum, range, sum, mean, median, mode, standard deviation (SD), Skewness and Kurtosis. The measured values for all the parameters (i.e. 238 U, 232 Th, 40 K and DR ) were slightly skewed (i.e. the distribution is approximately symmetric) since most of the measure of the The calculation of coefficient of variation (CV) also reveals the variability in the distribution of the measured activity concentrations of 238 U, 232 Th, 40 K and the radiation dose rate in the study area. CV ≤ 20% indicates little variability, 20 < CV ≤ 50% implies moderate variability, while 50% < CV ≤ 100% indicates high variability and CV value greater than 100% is regarded as exception-ally high variability [ 12 , 21 ].The Pareto chart was plotedto showthemost significant factor (set) in the dataset ofeachmeasuredradiogicalparameter. These chartsareshown in Fig. 2 (a)-(d).

Correlation analyses
The correlation analysis between the measured activity concentrations of the natural radionuclides and the radiation dose rate was conducted using Pearson techniquesto further investigate theirdegreeofstrengthandnatureof the relationship. The results are given in Tables 5 and 6 . The results were classified according to the correlation coefficient R [ 12 , 22 ], as follows: 0.8 ≤ |R| ≤ 1 suggests a strong correlation; 0.5 ≤ |R| ≤ 0.8 suggests a significant correlation; 0.3 ≤ |R| ≤ 0.5 suggests a weak correlation; and |R| < 0.3 suggests an insignificant correlation.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships which have, or could be perceived to have influenced the work reported in this article.