Annual Effective Dose Research Articles

Assessment of indoor radon concentration in the dwellings of the industrial areas of Kannur District, Kerala.

All organisms on the earth-crest are exposed to natural background radiation since the evolution of the earth, as many environmental matrices such as soil, air, water bodies, vegetation, etc., act as the sources of natural radioactivity. The present study deals with the evaluation of indoor concentration of 222Rn (radon) in different dwellings with various construction materials used for the roof and floor in the industrial sites of Kannur district, Kerala. A pinhole-based dosemeter coupled with LR-115 Solid State Nuclear Track Detector and Direct Radon Progeny Sensor (DRPS) were respectively used for the measurement of indoor radon concentration and equilibrium equivalent concentration of radon. The indoor radon concentrations were found to vary from 102.30 Bqm-3 to 184.75 Bqm-3 and the values were within the recommended limits provided by International Commission on Radiological Protection (ICRP). The annual effective doses and excess lifetime cancer risks were observed in the range of 2.58-4.66 mSvy-1 and 7.68×10-3-15.60×10-3, respectively, and both exceed the world average values recommended by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2000. The study shows that, the houses with marble floors and concrete roofs have comparatively higher values of radon concentration, which indicates the significant contribution of construction materials to the enhanced radiation levels inside the dwellings.

Assessment of natural radioactivity concentration in the soil samples from the Churchandpur and Ukhrul districts of Manipur, India.

The natural radioactivity concentration was studied for 40 soil samples of the Churchandpur and Ukhrul districts of Manipur, India, by using gamma-ray spectroscopy. The average radioactivity concentration of 226Ra, 232Th and 40K in Churchandpur was found as 39.9 (range: 30-56), 72.1 (range: 57-93) and 564.1 (range:360-867) Bqkg-1 respectively, whereas, in Ukhrul, average radioactivity for the same was found as 30.3 (range: 16-54), 54.2 (range:24-89) and 637.1(range:103-901) Bqkg-1, respectively. The calculated radioactivity parameters were compared with the world average values. The measured radium equivalent activity (Raeq), absorbed dose rate ($\dot{\mathrm D}$), annual effective outdoor dose(Ė) and the external hazard index (Hex) were observed as 165 (range: 63.7-234.8) Bqkg-1, 77.6 (36.9-108.0) nGyh-1, 0.11 (0.05-0.13) mSvy-1 and 0.5 (0.1-0.6), respectively. This study aims to provide baseline data for radionuclide present in the Churchandpur and Ukhrul districts of Manipur.

Assessment of naturally occurring radionuclides in surface soil and drinking water from western part of Yadgir district Karnataka, India.

Radionuclide activity of the selected radionuclides 238U, 232Th and 40K was measured in surface soil samples collected from 40 villages of the western part of Yadgir district of Karnataka. A 4″×4″ NaI (Tl) detector based on a gamma spectrometer is used for the estimation of radionuclides. The major type of soil in this region is sandy and red. The 222Rn activity concentrations in drinking water were determined by the Emanometry method. The 222Rn activity in ground water is found to vary from 1.73 to 155.6Bql-1. The total annual effective doses because of 222Rn inhalation and ingestion range from 4.72 to 424.84μSv y-1 with an average value of 108.8μSv y-1, respectively. Among the sampling stations, Shahapur and Shorapur soil samples show higher activity values than the Kembhavi and Hunasagi sampling stations soil samples.

Radiological impact of hydrocarbon waste release on drinking water of ughievwen and udu communities, delta state Nigeria

Well water quality has been characterized with constant and continuous changes via the interaction of rock, soil and natural nano-filters which terminates at the aquiferous layer for clean well-water collection. The continuous exploration and production of crude oil has resulted significant increase of unwanted elements such as naturally occurring radionuclides in the water-bed which necessitates this study. The study determines the radionuclides based health impact or hazards associated with drinking water from crude oil exploration/production release in Ughievwen and Udu communities of Delta State, Nigeria. Sixty well water samples (three samples from each community) were collected and analyzed using sodium iodide (Nal (Tl)) detector. The obtained mean values of 238U, 232Th and 40K are 6.91 ± 1.62BqL−1, 4.39 ± 1.47 BqL−1 and 24.54 ± 1.59 BqL−1 respectively. The 238U, 232Th and 40K results showed that the measured values are higher than the world standard (UNSCEAR; WHO) and the control values The mean values of total annual effective dose of different age groups are: 11.08 mSvy−1, 2.54 mSvy−1, 1.93 mSvy−1, 2.52 mSvy−1, 7.03 mSvy−1 and 1.12 mSvy−1 respectively. While the mean committed effective dose of adult is 55.94 mSvy−1. The total annual effective dose, committed effective dose, cancer risks and hereditary effects are all lower than recommended limit (WHO; ICRP; USEPA) and reported scientific values except 11.08 mSvy−1 and 7.03 mSvy−1 that are higher than limit. It is evident from obtained results that the drinking water may not be radiologically safe for use by the public, which necessitates routine monitoring and caution to circumvent increase in radiation and the radiological of the studied communities’ drinking water. This is to avoid long term radiological risk arising from accumulation of such release in the studied communities.

Activity concentration of indoor radon and its short-lived progeny (218Po, 214Pb, and 214Po) and their effect on atmospheric ionization rate in Sana'a, Yemen

Exposure to ionizing radiation inside houses, especially radionuclides of radon and its progeny, poses serious health risks that can be exacerbated when inhaled as a result of interaction with human lung tissue. Also, air ionization is mainly due to these radionuclides. Therefore, accurate measurements of radon activity concentrations and its short-lived progeny are required to assess dose and environmental pollution and estimate ionization rates in indoor environments. For this purpose, we employed a previously tested and approved reliable method, following the three-count procedure. This method is based on airborne radon progeny sampling on polycarbonate membrane filters and alpha counting using a passive α-dosimetry technique with CR-39 detectors. The method also relies on a PC-based software we developed for solving mathematical equations and calculating all the necessary physical quantities. In this study, the concentrations of radon and individual short-lived radon progeny were measured in 20 houses in Sana'a, Yemen. Measurement conditions and meteorological variables were considered. The average activity concentrations of 222Rn, Equilibrium-Equivalent Concentration (EEC), 218Po, 214 Pb, and 214Po were 73.1 ± 6.0, 29.2 ± 2.4, 44.4 ± 3.6, 30.5 ± 2.5, and 23.2 ± 1.9 Bq.m-3, respectively. The calculated average unattached fractions f1(218Po), f2(214 Pb), and fp were found to be 0.24, 0.04, and 0.07 % respectively. The annual average values of ion-pair production rate caused by 222Rn and their progeny and air ion concentration, were 27.25 ions.cm-3s-1 and 1829 ions.cm-3 respectively. The annual effective dose was estimated to be 1.93 ± 0.16 mSv.y−1, well lower than the recommended 10 mSv.y−1.

Reduction of detection limits in monitoring of internal exposures by a combined evaluation of emissions and spectra

Routine monitoring of internal exposures requires the detection of effective doses of at most 1 mSv per calendar year. For some radionuclides, this requirement cannot be satisfied by a conventional evaluation of the spectra that are gained in alpha or gamma spectrometry. However, since several measurements are conducted per calendar year on a regular basis, a combined evaluation of measurements, i.e. the evaluation of sum spectra, is possible. Additionally, radionuclides that feature several emissions of alpha or gamma radiation allow a combined evaluation of their emissions. Both methods can lead to significantly smaller detection limits as compared to a separate evaluation of spectra in many cases. However, the variation of parameters that influence the evaluation such as the measurement efficiency, abundance and chemical yield requires specific calculations and treatments of the spectra as well as a manipulation of the channel contents: In a combination of emissions, energy regions are summed and evaluated with a combined efficiency that is weighted by the abundances. In a combination of spectra, the channel contents must be scaled by the ratio of the calibration factors before the summation of the spectra. In the routine monitoring of short-lived radionuclides that feature a variety of emissions such as 225Ac, these combinations are particularly effective in reducing the detectable annual effective dose. For alpha spectrometry of 225Ac, both methods applied together can lead to a detectable effective dose of about 1 mSv per year as compared to a dose of about 90 mSv with a conventional separate evaluation.

Calculation the Excess Lifetime Lung Cancer Risk and Human Health Risk Assessment by Inhalation of Radon Gas in the Health Centers of Al–Hay City in Wasit, Iraq Using LR-115 Detector

In this paper, the technology used to measure radon concentrations in 8 health centers of Al- Hay city in Wasit, Iraq (December 2019) is one of the types of solid state nuclear track detectors, LR-115. After that, the annual effective dose rate and the excess lifetime cancer risk were calculated for the selected positions in the study area. The detectors were exposed to radon for 45 days, the etched detectors, using an optical microscope, to calculate the track densities, essentially depend on the alpha ray emitted from radon which later on easy converted to radon concentration values. Radon concentration ranges are from (183.47±22.93 to 17.15±2.14) Bq/m3 with a mean of (100.483Bq/m3), which lower than the appropriate radon levels recommended by ICRP "International Commission on Radiological Protection". The readings of "Excess Lifetime Cancer Risk" (ELCR), which ranges from 3.9 ×10-3 to 8.05 ×10-3 with an average value of 0.53% showing that human health is not under risk even it does not develop any lung cancer while human inhale the radon.

Analysis of data on levels of public exposure to natural sources of radiation in the Ivanovo region

The paper presents the results of analysis of the Ivanovo Regional databank of radiation doses to the pub-lic from exposure to natural and technologically enhanced radiation background for 2008–2022. Despite the fact that the average individual annual effective dose of public exposure due to natural sources of radiation in the Ivanovo region calculated for the whole 15-year period (4.63 mSv/year) does not qualify as increased (i.e. does not exceed the level of 5 mSv/year), in some years of the period under review the average dose repeatedly exceeded this level, reaching 7.50 mSv/year. The analysis of the structure of the doses of public exposure due to natural sources of radiation in the Ivanovo region showed that the contribution of the dose from internal exposure to radon, thoron and progenies according to measurement results from 2008–2022 ranged from 65.98 to 81.47%. The paper provides examples of buildings of different types in settlements of the Ivanovo region, in which the indoor radon isotopes equilibrium equivalent concentrations are more than 1.5 times higher than the established action level for existing dwellings and public buildings (200 Bq/m3). Despite the significant amount of measurement data in the Regional databank, it is necessary to obtain additional information on the indoor radon levels in existing wooden and other low-rise dwellings and public buildings in the most radon-prone areas of the region. For this purpose, a radon survey is planned for 2024-2026 in the cities of Ivanovo and Kohma, Privolzhsky, Gavrilovo-Posadsky, Teykovsky and Zavolzhsky districts of the Ivanovo region within the framework of a joint project of Saint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev, the Directorate of the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing in the Ivanovo region, and the Center of Hygiene and Epidemiology in the Ivanovo region.

Assessment of radiological hazards of soils from the city of Bitola (Macedonia) and its environs

ABSTRACT To establish the radioactivity level of soils and assess the associated radiological impact on residents, 58 samples from the town of Bitola and its environs were collected. After conducting gross alpha and gross beta measurements with a gas-flow proportional counter as a preliminary screening test, subsequent gamma-spectrometry measurements reveal the presence of 40K, 226Ra, 232Th, and 137Cs in the soil samples as radionuclides with the highest impact. The absorbed gamma dose rate, the annual effective dose, radium equivalent activity, external hazard index, gamma index, excess lifetime cancer risk, and annual gonadal dose were calculated using the obtained activity concentrations of the radionuclides. Upon comparison with similar studies conducted in the Balkan countries, the obtained results for radiation hazard indices were found to be the highest in the region. Coloured maps were generated to visually represent the spatial distribution of the absorbed gamma dose rate in air and annual effective dose, clearly indicating the combined influence of geology and human activities, including the nearby thermoelectric power plant operation.

Assessment of the level and risk of radioactive hazards in coastal sediments in northern Vietnam

ABSTRACT Radioactivity in coastal sediments in northern Vietnam was examined using data from five sediment cores to assess radioactivity concentrations and radiation risk indices. Radiation risk indices included radium equivalent activity (Raeq), the absorbed dose rate (ADR), the annual effective dose equivalent (AEDE), the activity utilization index (AUI), the external hazard index (Hex), the representative level gamma index (Iγr), and the annual gonadal effective dose rate (AGDE). The radioactivity concentrations of 40K, 232Th, 226Ra, 238U, and 137Cs were 567, 56.1, 35.1, 37.9, and 1.18 Bq/kg, respectively. The average concentrations of 40K, 232Th, 226Ra, and 238U were above the global average at five sites, except for 137Cs, which was low. The Raeq, Hex, and AUI indices were below the recommended values, while the AEDE, ADR, AGDE, and Iγr indices were above the recommended values. Moreover, 40K, 232Th, 226Ra, and 238U had significant impacts on the radiation hazard indices Raeq, ADR, AEDE, Iγr, AUI, Hex, and AGDE. There are three coastal sediment groups on the northern coast of Vietnam: Group 1 has a higher radioactivity and radiation risk index than Group 2 but a lower value than Group 3. Group 3 had the highest radioactivity and radiation risk index. The values of 40K, 232Th, 226Ra, and 238U and the ADR, AUI, Iγr, and AGDE indices in the sediment threaten the living environment.

Assessment of soil moisture on radon levels, radon exhalation, natural radioactivity, and radiological risks in offices and laboratories in GAEC

This study investigates the influence of moisture on soil radon exhalation, natural radioactivity in soil, and indoor radon concentrations in offices and laboratories at the Ghana Atomic Energy Commission (GAEC) and their associated radiological risks to workers. Radon exhalation rates were determined using the Sealed Can method. CR-39 SSNTD detectors were used to measure indoor radon concentrations. Gamma spectroscopy using HpGe detector was used to determine the activity concentrations of U-238, Ra-226, Th-232, and K-40 in the soil samples. The results showed mean concentrations of 14.3 ± 2.0 Bq/kg (CI 95%: 10.0–18.0) for U-238, 145.0 ± 10.0 Bq/kg (CI 95%:123.0–167.0) for K-40, 31.5 ± 6.0 Bq/kg (CI 95%: 24.0–39.0) for Th-232, and 15.6 ± 2.0 Bq/kg (CI 95%:14.0–29.0) for Ra-226. The results showed mean surface and mass exhalation rates of 6.9 ± 2.3 × 10−4 Bq/m2/h1 (CI 95%: 5.7 × 10−4 –12.6 × 10−4) and 2.4 ± 0.4 (CI 95%: 1.9–4.2) nBq/kg1/h1 respectively. The findings revealed mean indoor radon concentrations of 93.0 ± 10.0 Bq/m3 (CI 95%: 88.0–98.0), 111.0 ± 12.0 Bq/m3 (CI 95%: 102.0–119.0) and 145.0 ± 13.0 Bq/m3 (CI 95%: 135.0–155.0) in the offices, laboratories, and basements respectively, with laboratories and basements exceeding the WHO reference level of 100 Bq/m3. A strong inverse relationship between moisture levels and exhalation rates (r = −0.8) was observed, leading to a negative correlation (r = −0.3). Between the moisture levels and indoor radon levels. The research findings indicated a mean annual effective dose of 0.6 mSv/yr. (CI 95%: 0.5–0.6) to the workers, which is well below occupational and public dose limits. The lung cancer cases of workers were computed which ranged from 0.9 × 10−8 to 1.2 × 10−8 cases per million people per year, which is less than the limit range of 170–230 per million people per year recommended by ICRP but remaining with safe radiological limits for workers. This study identified moderate radon exposure risks at the GAEC, exceeding the WHO recommendation. The correlation and trend analysis demonstrate strong relationships between moisture, exhalation rates, radium, and indoor radon.

Simultaneous indoor radon/thoron and in situ outdoor gamma dose measurements and estimation of annual effective dose in a tin mining area of Jos Plateau, Nigeria.

Radon, a radioactive gas can increase the risk of lung cancer when breathe in. Indoor Rn-222 and Rn-220 concentrations were determined using passive radon monitor in some dwellings in a Sn mining area of Jos Plateau. Outdoor gamma radiation was also measured with a hand-held survey meter. The range of Rn-222 and Rn-220 concentrations was from 7-53Bq m-3 to 41-267Bq m-3 with averages of 27±17 and 92±65Bq m-3, respectively. The mean total effective dose due to Rn-222+Rn-220 was estimated as 2.84±1.57mSv y-1. Rn-220 contributed between 50 and 95% to the total annual effective dose. There was no correlation between indoor Rn-220 and Rn-222 concentrations in the dwellings. Outdoor gamma radiation measured was between 0.31±0.06 and 0.62±0.08μSv h-1, and mean annual effective dose calculated was 1.14±0.21mSv y-1. It is concluded from this study that thoron should not be neglected in dose assessment.

Assessment of radon in traditional building materials using polymeric nuclear track detector

Natural uranium deposits decay into radon gas, a radioactive element that is produced spontaneously. It is a radioactive gas that adversely affects the human population because it can be ingested and inhaled internally, contaminating living tissue, especially DNA, through the ionizing process that increases free radical bodies and increases the risk of cancer. The present study is carried out to determine the radon concentration for some traditional building materials in Egypt by using the nuclear track detector (CR-39). The values of radon concentrations measured by CR-39 ranged from 40.5 ± 3 to 593.2 ± 13 with an average value of 180 ± 6 (Bqm−3). The average values of both surface and mass exhalation rates are 6.3E-04 (Bqm−2h−1) and 7.01E-06 (Bqkg−1h−1) respectively. Pearson’s correlation analysis shows a direct and great correlation between 222Rn, and all variables indexed particularly the annual effective dose with significance at 0.01. The current study helps to create baseline data to assess any anomalies in the level of background radioactivity at Egyptian houses. In addition to applying radiation protection strategies for public and occupational regarding the permissible and recommendation limits by ICRP, and IAEA.

Assessment of environmental radioactivity concentration and effective dose rates from radon gas exposure from water samples in Gezira State, Sudan

A study was conducted in Gezira State, Sudan, to estimate the concentration of radon and the annual effective dose rate in water samples based on inhalation, ingestion, and age group. The study collected 26 samples from different locations. The results showed that the mean concentration of radon was 7.68 ± 1.07 Bq.l−1, and the mean effective dose rate of radon released from water to indoor air was 19.17 ± 2.68 μSv.y−1. The average effective dose rates calculated from ingestion, inhalation, and the total annual effective dose rate were 18.81 ± 2.63, 19.34 ± 2.71, and 38.15 ± 5.34 μSv.y−1, respectively. The annual effective dose rates for infants, children, and adults were calculated to have mean values of 80.60 ± 11.27, 53.73 ± 7.51, and 38.38 ± 5.37 μSv.y−1, respectively. The study found that 23.1% of the samples exceeded the maximum contamination level, while 76.9% were below the reference levels set by the USEPA, WHO, and EU. Despite the increase in radiation dose with age and consumption rates, the radiation dose from water was lower than the recommended limits set by UNSCEAR and WHO. Additionally, the bronchial epithelium received twice the radiation dose compared to the stomach walls.

Assessment of environmental hazard impacts in building materials (Marble), Gabal El-Galala El-Bahariya, Northeastern Desert, Egypt

Galala limestone is widely used for construction and ornamental purposes and is known throughout the world under many commercial names, including Galala White, Galala Golden, Galala Creama and Galala Classic. Using a HPGe spectrometer, about 20 samples from the marble building industry were radiometrically analyzed and the gamma radiation emitted by the radionuclides 238U, 232Th and 40K was evaluated. The measurements performed showed that the concentrations of these radionuclides were 15 ± 13, 6 ± 4 and 1100 ± 330 Bq kg−1, respectively. It's important to note that all these recorded values do not exceed the internationally reported average levels of 33, 45 and 412 Bq kg−1for each individual element. The annual effective dose (AED) was estimated. The mean value of AED, 0.07 mSv/y, is comparable to the permissible average of 0.07 mSv/y, respectively. The relationship between radionuclides and their radiological hazard characteristics was studied using various multivariate statistical techniques such as Pearson correlation, principal component analysis (PCA), and hierarchical cluster analysis (HCA). The results indicate that the main contributors to the radiological hazard associated with marble are uranium and potassium. As a result, the use of marble in building materials may not pose a significant risk to public health.

Assessment of Radon Contamination in Drinking Water Sources Around Babban Tsauni Gold Mining Area, Federal Capital Territory, Nigeria

ABSTRACT Radon, a naturally occurring radioactive gas, is produced through the disintegration of radionuclides like uranium, thorium, or radium in the earth's crust. In this study, the radon levels and the annual effective dose from drinking water sources were assessed in Babban Tsauni, Gwagwalada, Nigeria, where artisanal gold mining is taking place. Water samples were collected and analyzed for 222Rn using liquid scintillation counter (Tri-Carb-LSA1000). The highest radon activity concentration was found in Dobi with a value of 3.215 Bq/L, while the lowest was found in Tsauni 7; 0.025 Bq/L. Both values were significantly below the maximum contamination level of 11.1 Bq/L and the world average value of 10 Bq/L, as established by USEPA and WHO respectively. The annual effective dose from ingesting radon was also below the permissible limit of 1 mSv/y for all age groups, the values for adult, children and infant ranged in mSv/y from 5.59E-07 to 2.35E-05, 8.39E-07 to 3.52E-05, 9.79E-07 to 4.11E-05 and 1.79E-07 to 2.55E-06, 2.68E-07 to 3.82E-06, 3.13E-07 to 4.46E-06 for ground and surface water sources respectively. This study concluded that the radon concentrations in the water sources remained within safe limits and that the anthropogenic activities of gold mining had no significant effect on the water sources.

Assessment of Radon Contamination in Drinking Water Sources Around Babban Tsauni Gold Mining Area, Federal Capital Territory, Nigeria

ABSTRACT Radon, a naturally occurring radioactive gas, is produced through the disintegration of radionuclides like uranium, thorium, or radium in the earth's crust. In this study, the radon levels and the annual effective dose from drinking water sources were assessed in Babban Tsauni, Gwagwalada, Nigeria, where artisanal gold mining is taking place. Water samples were collected and analyzed for 222Rn using liquid scintillation counter (Tri-Carb-LSA1000). The highest radon activity concentration was found in Dobi with a value of 3.215 Bq/L, while the lowest was found in Tsauni 7; 0.025 Bq/L. Both values were significantly below the maximum contamination level of 11.1 Bq/L and the world average value of 10 Bq/L, as established by USEPA and WHO respectively. The annual effective dose from ingesting radon was also below the permissible limit of 1 mSv/y for all age groups, the values for adult, children and infant ranged in mSv/y from 5.59E-07 to 2.35E-05, 8.39E-07 to 3.52E-05, 9.79E-07 to 4.11E-05 and 1.79E-07 to 2.55E-06, 2.68E-07 to 3.82E-06, 3.13E-07 to 4.46E-06 for ground and surface water sources respectively. This study concluded that the radon concentrations in the water sources remained within safe limits and that the anthropogenic activities of gold mining had no significant effect on the water sources.

Survey of Radiological Parameters at a Dumpsite Near an Oil and Gas Facility in Bayelsa State, Nigeria

The issue of proper waste management is becoming more critical with the increase of civilization and urbanization. Waste generation and disposal could increase levels of human radiation exposure. The dose rates from possible radioactive materials at Gbaraun-toru dumpsite have been investigated. Radiation survey meter was used to assess the dose rates at the site. Model equations were also used to estimate the health-related radiological parameters for the flux of scavengers and individuals using the dump site. The values of the measured dose rates at the dumpsites lie between (0.01 – 0.016) mRh-1 with a mean of 0.013 mRh-1. Absorbed dose rates and equivalent dose rates estimated ranged from (87.4 – 139.4) with a mean of 116.2 and (0876 – 1.402) with a mean of 1.113 . Annual effective dose rates, organ doses, and the excessive lifetime risk of cancer ranged from (0.357– 0.572) with mean 0.454 mSvy-1, (0.139 – 0.248) and (0.94 – 1.54) × 10-6 with mean of 1.28 × 10-6 respectively. Conclusively, the estimated absorbed measured rates for the study are above the safe limit (54 nGyh-1), while, others are within the safe limit (1 mSvh-1). This suggests that there may be an increment in the level of exposure of the workers at the dump sites, hence, regular radiological studies should be carried out in the study area

Radiological Risk Assessment of Uranium, Thorium and Potassium in Siluriformes and Oreochromis Niloticus in Baga, Borno State

The study of radiological risk assessment plays a crucial role in understanding the potential impact of radioactive elements on the environment and human health. Uranium, thorium, and potassium are naturally occurring radioactive elements commonly found in various geological formations worldwide. Their presence in aquatic ecosystems, such as rivers, lakes, and reservoirs, raises concerns regarding potential exposure and associated risks to aquatic organisms and humans (Ajayi et al., 2018; Syarbaini et al., 2014; Hamidalddin et al., 2016). In October 2023, two fish samples were obtained from Baga, Kukawa, Borno State. Sample A was catfish, while Sample B was tilapia. The amounts of uranium, thorium, and potassium were the main topics of the radiological risk assessment performed on the samples. Following a seven-day sun-drying process, the fish were ground into a powder and carefully sent to the Obafemi Awolowo University's Centre for Energy Research and Development in Ile-Ife, Osun State. The findings showed that both catfish and tilapia contain certain radionuclides (uranium, thorium, and potassium), their anticipated annual effective dose rates from consumption are relatively modest. It was discovered that the computed dose rates for tilapia (Sample B) and catfish (Sample A) were significantly lower than the global average for the yearly effective dosage limit for the general public, which is normally set at 1 millisievert (mSv) annually. In particular, the estimated annual effective dose rate were 3.190758 μSv/year and 4.021574 μSv/year for Sample A and B respectively. These results imply that eating tilapia and catfish is unlikely to expose the general public to radiation levels higher than dose recommended by international agreements. The investigation concludes that eating tilapia and catfish is compliant with international standards for radiation exposure from food. Nevertheless, maintaining ongoing food safety procedures depends on constant observation and adherence to changing regulations.

Assessment of Naturally Occurring Radionuclide in Soil Samples from Kutayi Mining Sites in Muya Local Government Area, Niger State, Nigeria

This work examines the Kutayi mining sites with a view of assessing the activity concentration and effective dose rate of NORM (i.e. 40K, 232Th and 226Ra) in these site absorbed in 8 soil samples collected from different areas within the Kutayi mining sites, A γ-ray spectrometry NaI (Tl) at CERT. ABU Zaria, was used to carry out the analysis of the soil samples. The result shows that, activity concentration for 40K ranged from 428.9269 to 93.6236 BqKg-1; for 226Ra it ranged from 50.1738 to 13.7891 BqKg-1 and for 232Th the ranged is from 52.1095 to 18.7457 Bq.Kg-1, the absorbed dose for 40K ranged from 17.8863 to 3.9041 ŋGy.h-1, for 226Ra the range is from 23.1803 to 3.1614 ŋGy.h-1 and for 232Th range from 31.47419 to 11.3224 ŋGy.h-1. The total mean absorbed dose rate is 42.5341 ŋGy.h-1 and the annual effective dose range from 0.0355 mSvy-1 (i.e. 36 – 76 μSv.y-1), with an mean annual effective dose of 0.0522 mSv.y-1 (i.e. 52.2 μSv.y-1, Also the mean Radium Equivalents (Raeq) obtained ranged from 64.0280 BqKg-1 (KT6) to 135.3245 BqKg-1 (KT8). This results show that, the Raeq is 370 BqKg-1 which is the requirement for soil to be used for dwellings; hence the soil from this site is suitable use for buildings. The mean Hext ranged from 0.1730 Bqkg-1 (KT6) to 0.3438 Bqkg-1 (KT8). The maximum allowed value of (Hext = 1) corresponds to the upper limit of Raeq (370 BqKg-1) in order to limit the external gamma radiation dose from the soil to 1.5 mGy y-1, i.e. index should Hext = 1. All these values for Iα are below the maximum permissible value of Iα= 1 which corresponds to 200 Bq.Kg-1. Hence no radiological hazard is envisaged to dwellers of the study areas and the miners working on those sites.