Measured Activity Concentrations Research Articles

ASSESSMENT OF THE COMMITTED EFFECTIVE DOSE EQUIVALENT AND ITS UNCERTAINTY FROM INCIDENTAL INTERNAL TRITIUM EXPOSURE.

The objective of the study was to estimate the committed effective dose equivalent from internal tritium exposure and its uncertainty in case of tritium incident at Mayak PA. According to worker's self-report, he had been exposed as a result of pouring "heavy" water over himself while performing technological operation in September 2019. Two-component exponential model of tritiated water (HTO) excretion including fast and slow phases was used to describe HTO content in the body. The individual's specific value of tritium biological half-life in the fast phase was 8.9days, which is close to the average value of 10days in the ICRP model. The slow-phase HTO excretion fraction is two orders of magnitude lower than the corresponding value in the ICRP model. The calculated committed effective dose equivalent (CEDE) due to tritium intake (7.4mSv) depended mostly on fast-phase excretion. The uncertainty factor calculated as ratio of the 97.5% quantile and the mean value was equal to 1.14. The contribution of the slow-phase excretion to the CEDE due to internal exposure was as low as from 0.1 to 0.2% of total CEDE. This demonstrates that after the case of a single intake of tritium, which we studied, the CEDE is determined mostly by the excretion in the fast phase. The metabolized organically bound tritium dose fraction was in the range from 0.3 to 2.0%. The use of all the results of the measurement of HTO activity concentration in urine made it possible to obtain a lower estimate of the uncertainty of the CEDE of internal exposure in comparison with the use of only the first measurement result.

Measurement of activity concentrations of rock samples from rocks- surrounded town in Igbeti, Oyo State, Nigeria

Rocks are known to contain radionuclides that emit radiation continuously. The assessment of activity concentrations of rock samples from Igbeti, Oke-Ogun has been investigated. Twenty (20) rock samples were randomly collected from different rock sites. The rock samples were pulverized at the laboratory of the Department of Geology, University of Ibadan. 200g of each collected sample was allowed to attain secular equilibrium by enclosing it in a plastic container for twenty-eight (28) days. Radiometric analysis of the samples was carried out at the radiation laboratory of the Physics Department of the Federal University of Agriculture, Abeokuta using a thallium doped Sodium Iodide detector. Standard equations were used to estimate the radiological parameters associated with exposure to ionizing radiation from the natural radionuclides in the rock samples. The study revealed that the activity concentrations of 226Ra, 232Th, and 40K lie between 14 ̶ 487 (Bq/kg), 210 ̶ 3680 (Bq/kg), and 242 ̶ 1580 (Bq/kg) respectively. The absorbed dose rate (nGy/h), annual effective dose equivalent (μSv/y), (radium equivalent (Bq/kg), external and internal indices, activity utilization index and estimated excess lifetime cancer risks lie between from (180 ̶ 2700) nGy/h, (0.10 ̶ 14), 400 ̶ 6300 (Bq/kg), 1 ̶ 17, 1 ̶ 19, 2 ̶ 41, and 0.6 ̶ 9.5 × 10−6 respectively. The values of the absorbed dose rates value are greater than the world average of 60 nGy/h while annual effective dose equivalent values are less than the world’s average value of 1000 μSv/y respectively. The external and internal indices are greater than the permissible limit of (1) and likewise, the radium equivalent value is also greater than the acceptable limit of 370 Bq/kg. The estimated excess lifetime cancer risk for the study is below the permissible limit of 2.9 × 10−4 . Most of the estimated radiological parameters for the study are all greater than the permissible limit. This suggests that further exposure of dwellers to ionizing radiation may be possible and this calls for further investigation.

Radiological hazard assessment and sensitivity analysis for soil samples in Taghdoua area of Ranyah, Saudi Arabia

In this study, twenty-two samples of soil were studied for 222Rn, 226Ra, 232Th and 40K using hyper-pure Germanium (HPGe) detector. The soil samples were collected from an inhabited area surrounding the small mountain in Taghdoua area of Ranyah. The measured activity concentrations of 226Ra, 232Th and 40K in the soil were found to vary from 6 to 54, 7 to 52 and 299–761 Bq kg−1, respectively. The radiological risk parameters including excess lifetime cancer risks and other relevant parameters were also evaluated. Furthermore, the effect of ventilation changes on both external and internal doses over a protracted exposure duration were studied through sensitivity analysis using RESRAD-BUILD computer code. The external doses were observed to be insensitive to ventilation while a considerable change was detected in the internal doses with ventilation. Hence, the investigated radiological risk parameters including the results from RESRAD were all below the recommended limit.

Measurement of Activity Concentration of 40K, 226Ra and 232Th in Commercial Wall Paints Used in Nigeria and Inherent Radiological Hazards

Ionizing radiations from building materials portend serious health risk to atoms and molecules of body cells by damaging tissues and altering the DNA in genes. In this study, the measurement of radioactivity concentration of 40K, 226Ra and 232Th to determine inherent radiological hazards in major brands of commercial wall paints used in Nigeria was carried out. Twenty paint samples were selected based on the popularity and quantity of sales of these paints’ brands as obtained from oral interview with these paints’ marketers. A NaI (Tl) detector (76×76 mm) was employed in the measurements. High mean levels of the radioactivity of 40K, 226Ra and 232Th were observed in emulsion paints 174.73, 58.18 and 56.98 Bq/kg while oil paints gave lower values of 119.66, 44.66 and 37.86 Bq/kg for 40K, 226Ra and 232Th respectively. From results obtained, most of the emulsion and oil paints available in Nigeria present low level of radioactivity concentration which does not pose significant radiological risk to user population. However, average excess lifetime cancer risk of these paints gave a value higher than the recommended limit. Based on this, regulation, quality control and constant monitoring of raw materials used for paint production in Nigeria is highly advised.

Performance evaluation of a European wide proficiency test on gross alpha/beta activity determination in drinking water

JRC-Geel organised a Europe-wide proficiency test on gross alpha/beta activity concentration measurements in water with 154 participants from the field of environmental radioactivity monitoring. The performance of the participants was evaluated by comparing their results to the reference value using percentage deviation, z-score and zeta-score. Many of the participants’ results deviated several orders of magnitude from the reference values regardless of the techniques used suggesting that the radioactivity monitoring of drinking water using gross-counting in Europe needs improving. Comparing with a similar proficiency test in 2012 reveals no major improvements and indicate that standards for gross-counting methods need revision. From the accompanied questionnaire, participants' measurement methods, laboratory practices and pitfalls were discussed. From the 14 best performing methods, JRC identified “Best practices”.

Estimation of public radiological dose from mining activities in some selected cities in Nigeria

Mining activities is one of the most significant sources of radiation exposure from long-lived naturally occurring radioactive materials (NORMs), and have resulted in unjustifiable public exposure doses which contravene radiation protection standards. As a result, estimating the extent of such exposure is essential for keeping the recommended public dose limit. This study therefore aims at estimating the public radiation dose around mining areas and its environs in some selected cities across Nigeria. Data on measured activity concentration of NORMs radionuclides comprising of U-238, Ra-226, Th-232 and K-40 from soil round mining areas in some selected cities in Nigeria were extracted from previous literatures and are used for public dose estimation using RESRAD computer code. From the calculated mean activity concentration, the results from each mining locations shows the maximum dose are lower than International Commission on Radiological Protection (ICRP), commended public dosage boundary of 1 mSv/yr with highest dose of 0.91 mSv/yr from Ra-226, Th-232 and K-40 over the period of 47.9 years reported from Gura Top mining site in Jos, Plateau State, while the lowest dose of 0.09 mSv/yr each over the period of 14.06 and 20.27 years occurred at Itagunmodi and Arufu sites for U-238, Th-232 and K-40. The highest dose recorded in Gura Top was due to numerous mining activities in the region. According to the ICRP, there is no safe level of radiation exposure. Therefore, there is need for competent authorities to conduct periodic assessment of radiation exposure from mining sites to ensure that all exposure emanating as a result of such activities are kept below the prescribed dose limit in accordance to the principle of As Low As Reasonably Achievable (ALARA), thereby ensuring public protection from unjustified radiation exposure.

222Rn Activity Concentration Measurement and its Radiological Risks in the Environment of Barserin Village, Erbil-Iraq

222Rn Activity Concentration Measurement and its Radiological Risks in the Environment of Barserin Village, Erbil-Iraq

Radiological impact of an active quarry in the Papuk Nature Park, Croatia.

Papuk Nature Park, unlike most similar parks and preserves in the world, contains active quarries. Quarries dig stone from the ground, creating dust and exposing deeper, potentially more radioactive layers. Since the forest trails in the Park lead right up to the quarries, we believed it was important to determine the radiological impact of the quarries on the Park environment. We measured ambient dose rate equivalent H*(10) and sampled moss at 26 Park locations along two of four quarries, along the road between them, and near Lake Orahovac, a very popular tourist destination close to the quarries. Moss is a standard bioindicator of exposure to heavy metals, including radionuclides. Using-gamma ray spectrometry we determined the activity concentration of 137Cs and of representative naturally occurring radionuclides – 238U, 226Ra, 210Pb, 232Th, and 40K – in sampled moss. H*(10) at selected locations was similar to the background H*(10) measured continuously all over Croatia. The ranges of measured activity concentrations of 137Cs and naturally occurring radionuclides in moss did not differ significantly from other parts of Croatia and nearby countries.

Population balance modelling captures host cell protein dynamics in CHO cell cultures.

Monoclonal antibodies (mAbs) have been extensively studied for their wide therapeutic and research applications. Increases in mAb titre has been achieved mainly by cell culture media/feed improvement and cell line engineering to increase cell density and specific mAb productivity. However, this improvement has shifted the bottleneck to downstream purification steps. The higher accumulation of the main cell-derived impurities, host cell proteins (HCPs), in the supernatant can negatively affect product integrity and immunogenicity in addition to increasing the cost of capture and polishing steps. Mathematical modelling of bioprocess dynamics is a valuable tool to improve industrial production at fast rate and low cost. Herein, a single stage volume-based population balance model (PBM) has been built to capture Chinese hamster ovary (CHO) cell behaviour in fed-batch bioreactors. Using cell volume as the internal variable, the model captures the dynamics of mAb and HCP accumulation extracellularly under physiological and mild hypothermic culture conditions. Model-based analysis and orthogonal measurements of lactate dehydrogenase activity and double-stranded DNA concentration in the supernatant show that a significant proportion of HCPs found in the extracellular matrix is secreted by viable cells. The PBM then served as a platform for generating operating strategies that optimise antibody titre and increase cost-efficiency while minimising impurity levels.

Recent Progress in Radon Metrology at IFIN-HH, Romania

The practical implementation of the European Council Directive no. 2013/59/EURATOM in Romania requires reliable indoor measurements of the radon (222Rn) activity concentration in air. In Romania, several Testing Laboratories were designated for radon activity and/or radon activity concentration in air measurements by the Romanian National Commission for Nuclear Activities Control (CNCAN). The calibration of the instruments used for indoor radon activity concentration measurements is very important. IFIN-HH, through its Ionizing Radiation Metrology Laboratory (LMRI), performed advanced research in the field of radon metrology, using radon standard sources prepared by LMRI, its radon chamber facility and a new reference radon monitor. The most recent results are described in this article. The radon chamber facility from IFIN-HH was technically improved, and new equipment and methods were set up and tested in order to provide new calibration services for customers. Additionally, calibration of the radon monitors was performed, as well as of the systems with solid-state nuclear track detectors, used for radon in air activity concentration measurements. IFIN-HH/LMRI obtained the CNCAN designation as Calibration Laboratory for installations measuring the radon activity concentration in air.

Effect of 90Sr and 137Cs concentration on Hematological Parameters of Bats in the Chernobyl Exclusion Zone (Ukraine)

We examined the effects of the level of internal 90Sr and 137Cs concentrations on hematological parameters of bats captured in the Chernobyl Exclusion Zone (Ukraine). In total, 68 animals of six bat species were live-monitored with measurement of the whole-body activity concentrations of the two radionuclides (90Sr and 137Cs) and blood sampling for further analysis. We found statistically significant positive correlations between the blood neutrophil count and whole-body 90Sr activity concentration in individuals of Eptesicus serotinus; and between the neutrophil/lymphocyte ratio and 90Sr concentration, and between the red blood cell (RBC) count and 137Cs concentration in Vespertilio murinus. We did not observe any correlation between concentrations of 90Sr and 137Cs and hematological parameters in individuals of Pipistrellus nathusii. Moreover, none of these three species showed significant sexual (male versus female) or age (adult versus sexually immature) differences in 90Sr and 137Cs concentrations. Our results contribute to better knowledge and understanding of the eco-immunology of free-ranging bats in one of the most radioactively contaminated areas in the world — the Chernobyl Exclusion Zone. To our knowledge, this is the first study investigating the relationship between radionuclide contamination and hematological parameters of bats.

Longitudinal and Comparative Measures of Serum Chitotriosidase and YKL-40 in Patients With Idiopathic Pulmonary Fibrosis.

BackgroundAlthough chitin is absent in humans, chitinases are present in healthy subjects and show dysregulated expression in a variety of diseases resulting from abnormal tissue injury and repair responses. It was shown that chitotriosidase (chitinase 1/CHIT1) and structurally-related chitinase 3-like 1 protein (CHI3L1/YKL-40) play important roles in the pathobiology of idiopathic pulmonary fibrosis (IPF), however little is known about their longitudinal serum levels and relationship to clinical measures in IPF.MethodsThe present study is the first to evaluate serial measurements of serum CHIT1 activity and YKL-40 concentrations in patients with IPF starting antifibrotic treatment and followed up for 24 months. In addition, baseline serum CHIT1 and YKL-40 were compared between patients with IPF and control subjects, and possible CHIT1 and YKL-40 relationships to longitudinal clinical assessments in IPF were explored.ResultsBaseline serum CHIT1 activity and YKL-40 concentrations were significantly elevated in patients with IPF compared to control subjects and showed similar discriminatory ability in distinguishing IPF from controls. No significant differences between the median serum CHIT1 activity and YKL-40 concentration measured over a study follow-up were noted. We found significantly elevated baseline serum CHIT1 activity in the progressors compared with the stables in the first year, while significantly increased baseline serum CHIT1 activity was noted in the stables compared to the progressors in the second year. Additionally, we observed a significant negative correlation between a change in serum YKL-40 concentration and a change in forced vital capacity (FVC) % predicted (% pred.) in the stables subgroup, whereas, a change in serum CHIT1 activity correlated negatively with a change in FVC% pred. in the progressors subgroup.ConclusionsThis explorative study findings add further evidence that CHIT1 and YKL-40 are upregulated in patients with IPF, and suggest that longitudinally stable serum CHIT1 activity and YKL-40 concentration levels may potentially be associated with the antifibrotic treatment response. In addition, our findings are supporting the possible role of CHIT1 and YKL-40 as candidate diagnostic and prognostic biomarkers in IPF. Further research is needed to validate present study findings.

Best practices for predictions of radionuclide activity concentrations and total absorbed dose rates to freshwater organisms exposed to uranium mining/milling

Predictions of radionuclide dose rates to freshwater organisms can be used to evaluate the radiological environmental impacts of releases from uranium mining and milling projects. These predictions help inform decisions on the implementation of mitigation measures. The objective of this study was to identify how dose rate modelling could be improved to reduce uncertainty in predictions to non-human biota. For this purpose, we modelled the activity concentrations of 210Pb, 210Po, 226Ra, 230Th, and 238U downstream of uranium mines and mills in northern Saskatchewan, Canada, together with associated weighted absorbed dose rates for a freshwater food chain using measured activity concentrations in water and sediments. Differences in predictions of radionuclide activity concentrations occurred mainly from the different default partition coefficient and concentration ratio values from one model to another and including all or only some 238U decay daughters in the dose rate assessments. Consequently, we recommend a standardized best-practice approach to calculate weighted absorbed dose rates to freshwater biota whether a facility is at the planning, operating or decommissioned stage. At the initial planning stage, the best-practice approach recommend using conservative site-specific baseline activity concentrations in water, sediments and organisms and predict conservative incremental activity concentrations in these media by selecting concentration ratios based on species similarity and similar water quality conditions to reduce the uncertainty in dose rate calculations. At the operating and decommissioned stages, the best-practice approach recommends relying on measured activity concentrations in water, sediment, fish tissue and whole-body of small organisms to further reduce uncertainty in dose rate estimates. This approach would allow for more realistic but still conservative dose assessments when evaluating impacts from uranium mining projects and making decision on adequate controls of releases.

Treatment for removing radium in soil and groundwater

The results of 226Ra activity concentration measurements in 50 soil and groundwater samples in Ninh Son region, Vietnam were evaluated in the present study. Average activity concentration in the soils was significantly higher than the worldwide average concentration in soils published by UNSCEAR, 2008. 90% of groundwater samples had concentrations of 226Ra that were higher than the USEPA drinking water standard. The results showed that there was a linear correlation between the 226Ra radioactivity in the soils and the concentration of 226Ra in the groundwater samples. The procedure for removal of 226Ra from soil and groundwater samples was built upon the chemistry behavior of radium. 226Ra in contaminated groundwater samples was removed by using MnO2 fiber. The removal efficiency of 226Ra reached ∼ 91% for the groundwater samples and ∼ 70% for the soil samples. Chemical removal of 226Ra from soils was investigated using a three-step extraction procedure (Easily leachable and exchangeable, Acid-reducible, and Oxidisable-organic). A moderate mobility of 226Ra (22–52%) was noted and mainly found in acid-reducible fractions, which suggests that 226Ra is mainly bound to Fe/Mn oxides and hydroxides. A multiple regression indicates that the 226Ra removal efficiency appears to be significantly dependent on Fe/Mn and organic matter content.

Measurement of Gross Alpha and Beta Activity Concentrations in Drinking Water from Sabon Gari Local Government Area of Kaduna State, Nigeria

The gross alpha and beta activity concentrations of eighteen water samples, consisting of boreholes and Hand-dug wells from Sabon Gari Local government area of Kaduna StateNigeria have been analyzed using, the potable single channel gas free MPC-2000B-DP detector. The results show that alpha and beta activity concentrations range from 0.96 × 10-2 Bq/L to 47.00 ×10-2 Bq/L and from 0.309 × 10-2 Bq/L to 310.40 × 10-2 Bq/L, for gross alpha and gross beta respectively. It is observed that in the overall samples, the gross alpha activity concentrations were below the 0.5 Bq/L maximum allowable limits for drinking water as recommended by World Health Organization (WHO). However, for the gross beta activity concentration, eleven (11) percent of the samples, have their activity concentrations greater than the 1.0 Bq/L maximum allowable limits for drinking water as recommended by the WHO. This high beta activity concentration in these areas might be due to the waste generated from industries and hospitals or as a result of the nature of farming activities occurring in the areas. Largely, results obtained are seen to be in agreement with reports from other authors within and outside Nigeria.

Isotopic signatures of plutonium and uranium at Bikar atoll, northern Marshall Islands

We present plutonium (Pu) and uranium (U) isotopic fingerprints (or signatures) in environmental samples collected at Bikar Atoll. Bikar is the second –most northern atoll of the Republic of the Marshall Islands, and therefore an important reference point to evaluate the extension of the regional fallout from the Pacific Proving Grounds (PPG) in Bikini and Enewetak Atolls. Previous studies have shown that regional fallout from atmospheric nuclear weapon testing (NWT) in Bikini and Enewetak has resulted in elevated levels of fallout radionuclides in this atoll. In order to optimally interpret the isotopic fingerprints, we compare our results with data obtained in eleven certified reference materials, representing different contamination sources. As well as 238Pu, 239Pu, 240Pu, 241Pu, 238U and 235U, this study also encompasses less commonly reported radionuclides such as 242Pu, 244Pu and 236U. We show the importance of combining numerous fingerprints for improved assessment of the source of a nuclear contamination.In samples from Bikar, Pu and U isotope ratios were found to vary within narrow ranges. Pu and U fingerprints suggest that regional fallout from the Castle Bravo test in March 1954 was the main source of the contamination. This was further confirmed by two different age dating approaches that estimated 1954 as the year of the contamination. We demonstrate that use of an exponential function to approximate the yield of heavy radionuclides in thermonuclear explosions with increasing mass is a valid approach for estimating the age of a contamination. We show that, if sufficient radionuclide activity concentration measurement results with low uncertainties are available, this method is robust.

Study, measurement and mitigation of radon activity concentration in the School of Computer Science of A Coruña in the North West of Spain

A study of the radon activity concentration was carried out at the School of Computer Science of ‘Universidade da Coruña’ (UDC, Spain). For this purpose, building location, the type of soil and the construction materials were analysed. Subsequently, the radon activity concentration was determined using two different techniques: measurement in situ with an on-site ionization chamber detector (short term) and measurement with trace detectors (long term). Based on the results obtained, and according with the Spanish Law (Spanish Official Bulletin—Boletín Oficial del Estado, of 21 December 2011, IS-33 Instruction), corrective works were performed, consisting on the installation of a forced ventilation system underneath the extent of the suspended floor in order to mitigate the high radon specific activity in the building. Four months and 3 years after the works, new measurements were carried out in order to verify the effectiveness of the new ventilation system, obtaining a decrease of the radon gas values ranging between 87% and 90%, which confirmed long term effectivity.

Measurement of Natural Radionuclides in Drinking Water and Risk Assessment in a Volcanic Region of Italy, Campania

The physical–chemical properties of water are closely linked to the geological nature of the site where they are located. This aspect becomes even more interesting when analyzing the natural radionuclides in the drinking water of a volcanic territory such as Campania in southern Italy. This study concerned the measurement of activity concentration of gross alpha and beta, radon, and tritium to evaluate their biological impact. The measurements were carried out using alpha spectrometry for alpha emitters, proportional counter for beta emitters, the electret system for radon in water, and finally liquid scintillation for the measurement of tritium concentration. The biological impact was assessed considering the indicative dose, if applicable, and the effective annual dose of radon. Although the results show that the values are below international and national references, the radiological characterization of drinking water is of fundamental importance to optimize the radiation protection of the population.

First in Human Evaluation and Dosimetry Calculations for Peptide 124I-p5+14-a Novel Radiotracer for the Detection of Systemic Amyloidosis Using PET/CT Imaging.

Accurate diagnosis of amyloidosis remains a significant clinical challenge and unmet need for patients. The amyloid-reactive peptide p5+14 radiolabeled with iodine-124 has been developed for the detection of amyloid by PET/CT imaging. In a first-in-human evaluation, the dosimetry and tissue distribution of 124I-p5+14 peptide in patients with systemic amyloidosis. Herein, we report the dosimetry and dynamic distribution in the first three enrolled patients with light chain-associated (AL) amyloidosis. The radiotracer was assessed in a single-site, open-label phase 1 study (NCT03678259). The first three patients received a single intravenous infusion of 124I-p5+14 peptide (≤37 MBq). Serial PET/CT imaging was performed during the 48 h post-infusion. Dosimetry was determined as a primary endpoint for each patient and gender-averaged mean values were calculated. Pharmacokinetic parameters were estimated from whole blood radioactivity measurements and organ-based time activity data. Lastly, the biodistribution of radiotracer in major organs was assessed visually and compared to clinically appreciated organ involvement. Infusion of the 124I-p5+14 was well tolerated with rapid uptake in the heart, kidneys, liver, spleen, pancreas, and lung. The gender-averaged whole-body effective radiation dose was estimated to be 0.23 (± 0.02) mSv/MBq with elimination of the radioactivity via renal and gastrointestinal routes. The whole blood elimination t1/2 of 21.9 ± 7.6 h. Organ-based activity concentration measurements indicated that AUClast tissue:blood ratios generally correlated with the anticipated presence of amyloid. Peptide uptake was observed in 4/5 clinically suspected organs, as noted in the medical record, as well as six anatomic sites generally associated with amyloidosis in this population. Peptide 124I-p5+14 rapidly distributes to anatomic sites consistent with the presence of amyloid in patients with systemic AL. The dosimetry estimates established in this cohort are acceptable for whole-body PET/CT imaging. Pharmacokinetic parameters are heterogeneous and consistent with uptake of the tracer in an amyloid compartment. PET/CT imaging of 124I-p5+14 may facilitate non-invasive detection of amyloid in multiple organ systems.

Environmental Risks Assessment of Kaolin Mines and Their Brick Products Using Monte Carlo Simulations

This study aimed to assess the radiological health implications to humans due to the use of kaolin from kaolin mines in Nigeria. A calibrated RS-125 spectrometer was used in-situ to monitor the activity concentrations of 40K, 238U, 232Th and dose-rate of kaolin minefields in Ilorin-south and Ilorin-west, Nigeria. The in-situ monitoring and measurements were done in 90 locations selected at random in the study areas. The in-situ measurements were consolidated via laboratory analysis of 48 samples of Kaolin bricks using lead-shielded NaI(Tl) detector. The estimated average values for all radiological hazard parameters for the in-situ measurements of Ilorin-west are higher than that of Ilorin-south minefield. However, the opposite was the case with the laboratory analysis of the bricks. This apparent conundrum was due to the higher values of 238U observed in the samples of bricks from Ilorin-south. In addition, the measured activity concentration of the primordial radionuclides in the Kaolin bricks from both mines are lower than the on-site measurements. This was attributed to the contribution from other terrestrial materials on-site. The 5th, 50th, and 95th percentiles of the cumulative probabilities for the excess lifetime cancer risk using the Monte Carlo simulation are 167.00 × 10–6, 281.00 × 10–6, 414.00 × 10–6 for Ilorin-west (in-situ), 104.00 × 10–6, 232.00 × 10–6, 392.00 × 10–6 for Ilorin-south (in-situ), 706.00 × 10–6, 1,250.00 × 10–6, 1,900.00 × 10–6 for Ilorin-west (lab), and 742.00 × 10–6, 1,480.00 × 10–6, 2,460.00 × 10–6 for Ilorin-south (lab), respectively. Therefore, the cancer risks are within the acceptable limits for both mining sites. This study is useful in developing radiation risk assessment models for decision makers in different fields of environmental sciences.