Gamma Radiation Levels Research Articles

The correlation between small papillary thyroid cancers and gamma radionuclides Cs-137, Th-232, U-238 and K-40 using spatially-explicit, register-based methods

A steep increase of small papillary thyroid cancers (sPTCs) has been observed globally. A major risk factor for developing PTC is ionizing radiation. The aim of this study is to investigate the spatial distribution of sPTC in Sweden and the extent to which prevalence is correlated to gamma radiation levels (Caesium-137 (Cs-137), Thorium-232 (Th-232), Uranium-238 (U-238) and Potassium-40 (K-40)) using multiple geospatial and geostatistical methods. The prevalence of metastatic sPTC was associated with significantly higher levels of Gamma radiation from Th-232, U-238 and K-40. The association is, however, inconsistent and the prevalence is higher in densely populated areas. The results clearly indicate that sPTC has causative factors that are neither evenly distributed among the population, nor geographically, calling for further studies with bigger cohorts. Environmental factors are believed to play a major role in the pathogenesis of the disease.

Investigation of Gebze-Darıca metro line (Kocaeli Province/Turkey) in terms of radon and gamma radiation levels

In this study, 222Rn and gamma radiation levels were measured in soil and rock samples taken from Gebze - Darıca Metro Line, which is under construction, within the borders of Kocaeli province (Turkey), which is an important industrial city. Measurements were made in the summer of 2021 and are interpreted by environmental factors such as depth, humidity, temperature, air pressure and geological formations (granite and non-granite) that may affect radiation levels. It was observed that radon concentrations were in the range of 145–3696 Bqm−3 in measurements made on soil samples. The highest radon values in rocks were measured in granodiorite (3242.8 Bq m−3) and granite (2253.4 Bqm−3) samples. The amount of radionuclide and radon in soils is higher than in rocks. In the measurements made at 48 selected points, the World Health Organization (WHO) limit value was exceeded at 27 points in total (%56 of all samples). There are six measurement points exceeding the limit values for both public and employees, with the highest annual average effective dose (H) for radon concentration of 2.94–23.55 mSv y−1 at S11. The highest surface radon exhalation rate was calculated as 508.02 Bq m−2 h−1 at station S11. Indoor measurements at 20 cm below the soil surface range from 81 to 252 nSvh−1, and all but S5 exceed the indoor gamma dose rate level of 84 nGy h−1 worldwide. Effective dose level caused by the gamma radiation originating from the Earth's surface, specified in the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) (2000) report, is exceeded 0.5 mSv y−1 at all stations. In the statistical analyzes based on X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) results, positive strong and moderate correlations were found between the average 222Rn concentration and weight percentage (Wt %) of K2O, Na2O, ThO2, ZrO2 oxides and Quartz, Montmorillonite, Albite minerals, respectively. Gamma radiation is correlated with Na2O Wt% content (R2 = 0.7056). A moderately negative correlation was found between the mean 222Rn concentration and temperature, a weak negative correlation with pressure, a weak positive correlation with humidity, and a moderately significant correlation with the presence of granite.

Natural background outdoor gamma radiation levels and mapping of associated risk in Siddipet district of Telanagana State, India

Studies on natural background outdoor environmental radioactivity levels were conducted in Siddipet district of Telangana state, India. The investigation was carried out in the major villages/mandal head quarters of the district using scintillation detector (NaI(Tl)) based μR- survey meter. The exposure rates measured on ground level and at 1 m height from ground (in μR.h−1) were converted into absorbed dose rates (in nGy.h−1) and annual effect doses (mSv) using appropriate conversion factors. The natural background radiation levels at 1 m height were found to vary from 139 nGy h−1 to 435 nGy h−1 with an average of 235±47 nGy h−1. The background radiation levels were observed to follow the normal distribution with a little deviation at the outliers. The excess lifetime cancer risk (ELCR) was also estimated.

Natural background gamma radiation levels: A village, Peddamula, in the vicinity of proposed uranium mineralized area, Nalgonda District, Telangana State, India

Natural background gamma radiation emanating from the radionuclides, which are present in the earth crust and materials used for construction, is inescapable feature for human beings. In the present study, a village “Peddamula” selected to estimate the natural background gamma radiation levels in the indoor and outdoor and activity of radionuclides in the soil samples, due to its proximity with proposed uranium mineralized area. The estimated gamma radiation levels with TLDs found to vary from 881 to 2017 μGy.y−1 with an average 1413 ± 248 μGy.y−1 in indoor. The activity of radionuclides estimated for U238, Th232 and K40 from soil samples are 163 ± 12 Bq.Kg−1, 176 ± 14 Bq.Kg−1 and 586 ± 46 Bq.Kg−1, respectively. The ratios between indoor and outdoor gamma radiation levels are found to be 1.14 and the estimated annual effective dose due to natural background gamma radiation is 1.14 ± 0.36 mSv.y−1. The Radium equivalent activity, Internal and External hazard index are also estimated and presented in the paper.

Cold season dose rate contributions from gamma, radon, thoron or progeny in legacy mines with high natural background radiation.

In areas with high natural background radiation, underground cavities tend to have high levels of airborne radionuclides. Within mines, occupancy may involve significant exposure to airborne radionuclides like radon (222Rn), thoron (220Rn) and progeny. The Fen carbonatite complex in Norway has legacy mines going through bedrock with significantly elevated levels of uranium (238U) and especially thorium (232Th), and significant levels of their progeny 222Rn and 220Rn. There are also significantly elevated levels of gamma radiation in these mines. These mines are naturally chimney ventilated and release large volumes of air to the outdoors giving a large local outdoor impact. We placed alpha track detectors at several localities within these mines to measure airborne radionuclides and measured gamma radiation of bedrock at each locality. The bedrock within the mines shows levels up to 1900Bqkg-1 for 238U, 12000Bqkg-1 for 232Th and gamma dose rates up to 11μSvh-1. Maximum levels of airborne radionuclides were 45000Bqm-3 for 220Rn and 6900Bqm-3 for 222Rn. In addition, we measured levels of thoron progeny (TnP). In order to estimate radiation dose contribution, TnP should be assessed rather than 220Rn, but deposition-based detectors may be biased by the airflow of mine-draft. We present dose rate contributions using UNSCEAR dose conversion factors, and correcting for airflow bias, finding a combined cold season dose rate within these mines of 17-24μSvh-1. Interestingly, fractional dose rate contributions vary from 0.02 to 0.6 for gamma, 0.33 to 0.95 for radon and 0.1 to 0.25 for TnP.

Determination of sentinel lymph nodes in gynecological cancer using the radiopharmaceutical Sentiscan. A case series

Background. Lymphadenectomy in patients with malignant female genital neoplasms is a necessary step of surgical treatment, the implementation of which allows assessing the the metastatic involvement of the removed lymph nodes and determining indications for postoperative treatment. Sentinel lymph node (SLN) biopsy with ultrastaging method appears to be a good alternative to standard regional lymph node removal with similar long-term oncologic outcomes and significantly lower rates of postoperative complications.
 Aim. To present the possibility of using a domestic radiopharmaceutical labeled with technetium-99m (Sentiscan) in patients with gynecological cancer.
 Materials and methods. A series of clinical cases of the use of Sentiscan during SLN biopsy in three patients suffering from cancer of the uterus and vulva is presented.
 Results. 1824 hours before the operation, 0.4 ml of the prepared solution of radiopharmaceutical 99mTc-Sentiscan with a total activity of 150 MBq was injected into the cervix of the uterus with tumors of the uterine body and into the vulva. After 2 hours, SPECT/CT was performed on the Discovery 670 DR (GE) of the abdomen and pelvis, followed by 3D reconstruction of images for better intraoperative navigation. Intraoperatively, a portable gamma detector Rad Pointer Gamma (Medikor Pharma Ural) was used to identify sentinel lymph nodes. Sentinel lymph nodes were removed in all patients, followed by a control assessment of the gamma radiation level, histological and immunohistochemical studies using panCK, CK18 markers.
 Conclusion. Presented clinical cases demonstrated high efficacy of sentinel lymph node mapping using radiopharmaceutical Sentiscan. Further studies are necessary for wide implementation of this technology in clinical practice.

GAMMA RADIATION EFFECTS ON THE PERFORMANCE OF MONO-CRYSTALLINE SOLAR CELLS

In this study, we present examples of solar cells that were subjected to various levels of 60Co gamma radiation. The solar cells we use are mono-crystalline, which has a stable crystal structure and high efficiency compared to polycrystalline. Prior to and during gamma irradiation, the current-voltage characteristics of monocrystalline silicon solar cells under AM1.5 light conditions and their photon spectral currents were examined. The results of the experiment demonstrate that as the dose of gamma radiation increases, solar cell metrics including open circuit voltage (Voc), short circuit current (Isc), and efficiency (η) drop. The photon spectral current demonstrates that as dose gamma is increased, the current decreases at shorter wavelengths and the defects are primarily produced near the solar cell's surface. Our findings demonstrate the gamma irradiation-induced breakdown of silicon solar cells and the minority carrier lifetime which demonstrates that the minority carrier lifetimes sharply decline with increasing radiation dose.

Low dose γ-radiation induced effects on wax moth (Galleria mellonella) larvae

Larvae of the greater wax moth Galleria mellonella are common pests of beehives and commercial apiaries, and in more applied settings, these insects act as alternative in vivo bioassays to rodents for studying microbial virulence, antibiotic development, and toxicology. In the current study, our aim was to assess the putative adverse effects of background gamma radiation levels on G. mellonella. To achieve this, we exposed larvae to low (0.014 mGy/h), medium (0.056 mGy/h), and high (1.33 mGy/h) doses of caesium-137 and measured larval pupation events, weight, faecal discharge, susceptibility to bacterial and fungal challenges, immune cell counts, activity, and viability (i.e., haemocyte encapsulation) and melanisation levels. The effects of low and medium levels of radiation were distinguishable from the highest dose rates used – the latter insects weighed the least and pupated earlier. In general, radiation exposure modulated cellular and humoral immunity over time, with larvae showing heightened encapsulation/melanisation levels at the higher dose rates but were more susceptible to bacterial (Photorhabdus luminescens) infection. There were few signs of radiation impacts after 7 days exposure, whereas marked changes were recorded between 14 and 28 days. Our data suggest that G. mellonella demonstrates plasticity at the whole organism and cellular levels when irradiated and offers insight into how such animals may cope in radiologically contaminated environments (e.g. Chornobyl Exclusion Zone).

Gamma spectrometry of coolant lines of KAMINI reactor

Gamma spectrometry of the KAMINI reactor coolant lines at the selected spots/locations was carried out during 20kWt power and shutdown using portable spectrometers such as RIIDEye-X, RayMon (Cadmium Zinc Telluride), and hyper pure germanium. 133Xe (81 keV),85m Kr (150 keV), and 135Xe (250 keV) isotopes could be identified. The spectra results did not indicate the presence of internal contamination due to any corrosion activation products such as 56Mn, 59Fe, 60Co, and fission products. The gamma radiation level observed during reactor power on the selected locations is only due to the fission product noble gases (FPNGs) and their short-lived radionuclides 88Rb and 138Cs generated and not any pipeline internal contamination. 137Cs and trace quantities of 60Co were identified in the mixed bed regenerated liquid. The presence of 137Cs could be attributed due to the tramp fuel fissions.

Imaging Neutral Particle Analyzer Engineering Design and Installation for the ASDEX Upgrade Tokamak

An imaging neutral particle analyzer (INPA) has been installed in the ASDEX Upgrade (AUG) tokamak to provide simultaneous measurements of the radial profile and the energy of the confined fast-ion (FI) population. The INPA diagnostic leverages the advantages of neutral particle analyzers (NPAs) and FI loss detectors (FILDs) by measuring charge exchange (CX) neutrals ionized by an ultrathin carbon foil is deflected into a scintillator by the local magnetic field. The design of this diagnostic has been developed under a series of constraints, such as the lack of space and hazardous environment (high level of neutron and gamma radiation), the need of high precision in the alignment of the nonsequential optical system (with six optical axes), and the optimization of the scintillator plate (signal emitter). To this end, a modular and adjustable design has been pursued with several degrees of freedom to ensure precise positioning during the installation and optical calibration. The induced electromagnetic and thermal stresses have been assessed and compared against the material limits of the detector, showing that no significant stress is expected for the system. The thermal analysis shows that the diagnostic scintillator can work efficiently during normal operation conditions. The CAD design, a comparison between the synthetic and real optical signals and the mechanical assessment [based on finite element analysis (FEA)], is presented in this contribution.

Design and Characterisation of an Optical Fibre Dosimeter Based on Silica Optical Fibre and Scintillation Crystal

In nuclear power plants, particle accelerators, and other nuclear facilities, measuring the level of ionising gamma radiation is critical for the safety and management of the operation and the environment’s protection. However, in many cases, it is impossible to monitor ionising radiation directly at the required location continuously. This is typically either due to the lack of space to accommodate the entire dosimeter or in environments with high ionising radiation activity, electromagnetic radiation, and temperature, which significantly shorten electronics’ lifetime. To allow for radiation measurement in such scenarios, we designed a fibre optic dosimeter that introduces an optical fibre link to deliver the scintillation radiation between the ionising radiation sensor and the detectors. The sensors can thus be placed in space-constrained and electronically hostile locations. We used silica optical fibres that withstand high radiation doses, high temperatures, and electromagnetic interference. We use a single photon counter and a photomultiplier to detect the transmitted scintillation radiation. We have shown that selected optical fibres, combined with different scintillation materials, are suitable for measuring gamma radiation levels in hundreds of kBq. We present the architecture of the dosimeter and its experimental characterisation with several combinations of optical fibres, detectors, and scintillation crystals.

Assessment of gamma radiation through agro-morphological characters in camellia sinensis L. (O.) kuntze

Purpose To study the effects of gamma radiation on tea seed germination, morphological changes, and genetic variation by using gamma radiation. Material and Method Fresh Tea seed material were irradiated with twenty different doses of gamma radiation such as 0, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80 90, 100, 200, 500 and 1000 Gy from Cobalt 60Co source from Regional Nuclear Agriculture Research Center, Bidhan Chandra Krishi Viswavidyalaya (BCKV), West Bengal, in between 2019 and 2020. Result and Conclusion The growth behavior of tea seedling was recorded under varying levels of gamma radiation and its performance at nursery stages. It was observed seed irradiated with doses from 35 Gy to 100 Gy could germinate but could not survive beyond five (05) months. When treated with higher doses as 200 Gy, 500 Gy and 1000 Gy, no seed germination takes places due to possible damages occur in the DNA structure. Screening of growth characteristics of tea plant generally monitored by the characteristics like plant height, number of leaves, number of primary branches, base diameter, and total leaf area of plants and we found that these characteristics significantly increased with the progress of time and increasing levels of gamma radiation; however, the plant height showed decreasing trend with the increasing levels of gamma radiation, which could be due to the change in chromosomal structure and genetic alteration. After 90 weeks of planting, the plant height, no. of primary branches, the number of leaves, plant base diameter, and total leaf area per plant recorded were 36.42 cm, 1/plant, 7.11/plant, 0.62 c.m, 22.92 cm2/plant respectively under the radiation level 30 Gy, whereas the corresponding figures of the above parameters at the control treatment were 85.32 cm, 1/plant, 18.84/plant, 1.18 c.m and 26.68 cm2/plant, respectively. The total plant height, no. of primary branches, the number of leaves, plant base diameter, and total leaf area per plant were significantly influenced by the rising levels of gamma radiation (up to 100 Gy), finally, after 90 weeks of planting, the maximum no. of branching was observed in the treatment of 8 Gy, 10 Gy and 15 Gy respectively. The study reveals a hitherto open the possibility of using gamma radiation on tea plant for creation of variation in the tea seed planting materials. Further studies on mutation using tea planting materials would give an insight into its mutable gene behavior.

Dose calibration of Health Canada's Fixed Point Surveillance system for environmental radiation monitoring in terms of air kerma and H*(10)

The environmental radiation exposure in Canada has been monitored since 2002 by Health Canada's Fixed Point Surveillance network. The network consists of over eighty 7.6 cm × 7.6 cm sodium iodide spectrometers, and routinely reports to the public the environmental gamma radiation level throughout Canada. This paper describes the latest dose calibrations to air kerma and ambient dose equivalent for the future upgraded network. The calibration curves were developed using Monte Carlo techniques and further optimized via experiments in various reference fields. The dose calibration was validated over a wide range of gamma energy, dose measurement range, and angle of incidence under laboratory conditions. In environmental monitoring situations, the angular distribution of radiation exposure was analytically calculated by assuming a semi-infinite plume source, semi-infinite planar source, and infinite volume sources for the respective exposure scenarios of radioactive plume, ground contamination, and soil source. By coupling the resultant radiation angular distribution with detector's angular variation on dose response, the overall accuracy of dose measurement in each of these environmental scenarios was estimated. The accuracy is expected to be within ±3.7% for plume radiation, −5.6% for 137Cs ground contamination, and 0% to −17.1% for soil radioactive sources. The under-estimation for soil sources is mainly caused by absorption of radiation in the electronic system underneath the crystal.

STUDIES ON GAMMA DOSE RATES IN OUTDOOR ENVIRONMENT AND ASSESSMENT OF EXTERNAL EXPOSURE TO PUBLIC IN STEPNOGORSK AREA, NORTHERN KAZAKHSTAN.

The present study is based on a pilot study, which showed that the Stepnogorsk area of Northern Kazakhstan represents sources of potential contamination of the living environment. The aim of the study was measurement of outdoor gamma radiation levels, activity concentration in soil samples and assessment of external exposure to the public. According to our analysis, the highest ${\boldsymbol{H}}^{\ast}$(10) values ∼2870 nGy h-1 were detected in the Aqsu school territory, which were slightly higher than the control readings for this region. The average 226Ra, 232Th and 40K activities were 617.8±3.2Bqkg-1, 188.3±2.9Bqkg-1 and 731.5±6.2Bqkg-1, respectively. The annual effective dose received by the Aqsu population ranged from 0.08 to 3.5mSv y-1, which was found higher by an order of magnitude than the upper annual dose limit. Changes in radiation background are an unfavourable factor for the population and may possibly become potential radiation risks for long-term effects.

Assessment of natural radioactivity level before and after a mud-volcano eruption: A study from Piparo mud-volcano, Trinidad and Tobago

The present study was conducted in the Piparo mud-volcano, which is situated in the central part of the island of Trinidad, is geologically connected with the Central Fault Range Zone (CFRZ). This fault zone is a neotectonic (active) strike-slip fault system and an extension of the Andes Mountain chain. This study was aimed at detecting the possible gamma radiation level in Piparo MV after its eruption in September 2019 and finding the change in the ambient radiation level after that eruption. To achieve this aim, gamma radiation data were collected for 6 months (three times at 3 months interval) after this eruption. As a pilot study, gamma radiation measurements were measured with the help of a portable Geiger Muller counter from 32 locations. Radiation levels were nearly 2 times higher than the average background levels in the country indicating Piparo mud-volcano could have controlled the elevated radiation levels in the area. Good correlations were also found between elevated radiation in the northern and western sides of the main crater and presence of auxiliary craters in the same sides. Previous studies reported that the northern side of the crater was more active, and the present study also supported their observation. Good correlation (with coefficient >0.9) indicates that these radioactivity values might be syngenetic. Continuous release and slow reduction of radiation levels (only 13% over 6 months) may indicate a continuous activity in Piparo mud-volcano and may support CRFZ as a creep fault.

A study on the level of terrestrial gamma and gross alpha activity in Gulf of Mannar, South coast of India, Tamil Nadu

This study presents the results of outdoor ambient gamma and gross alpha activity of Gulf of Mannar, and these measurements were carried out using Scintillation Counter (UR-705). Results showed that the terrestrial Gamma radiation levels of the Gulf of Mannar ranged from 4.10 μR/h to 76.33 μR/h. The Gross alpha radioactivity levels of the Gulf of Mannar ranged between 3.67 Bq/kg and 51.34 Bq/kg. The calculated ambient gamma and gross alpha activity were found to be lower than the world average. Gamma absorbed dose rates in air outdoors were calculated to be in the range between 35.67 nGy/h and 664.07 nGy/h with an arithmetic mean of 98.98 ± 20.54 nGy/h. This value is lower than the population-weighted world-averaged of 60 nGy/h. Inhabitants of Northern Gulf of Mannar are subjected to external gamma Annual dose exposure ranging between 0.30 and 5.65 mGy/y with an arithmetic mean of 0.84 ± 0.17 mGy/y.

Assessment of environmental radioactivity and groundwater quality around Tummalapalle uranium mining site, Andhra Pradesh, India

A comprehensive background radiological status in the surrounding environment of the Tummalapalle U mining and processing facilities was evaluated. Radioactivity in soil and rock was estimated by high-resolution gamma spectroscopy with a high-purity p-type germanium detector. The external gamma radiation level, outdoor 222Rn concentration, radioactivity in the groundwater, and water quality parameters around the Tummalapalle site were studied. The terrestrial radioactivity in soil was higher than the national and global averages in the study region. Radium equivalent activity (Raeq) in soil and rock was much lower than the safe limit of 370 Bq/kg and therefore safe to use as a construction material. Hydrogeochemical analysis indicated that the groundwater in the study region is neutral to medium basic, oxic, fresh to brackish, and predominantly Ca2+-Mg2+-HCO3 − (62.5%) type. The hydrogeochemistry of groundwater was primarily governed by rock-aquifer interaction in this region. The data generated in this study can serve as the baseline for this region to understand the change in environmental conditions, if any, due to prolonged anthropogenic activities.

Assessment of gamma radiation levels in soil samples from Sylhet using High Purity Germanium Detector and Estimation of population exposure

Assessment of gamma radiation levels in soil samples from Sylhet using High Purity Germanium Detector and Estimation of population exposure

Gamma-radiation levels outdoors in Great Britain based on K, Th and U geochemical data

Gamma-rays from naturally occurring radionuclides are a major component of background radiation. They are an important tool for geology and are also important for radiation protection. In this paper we use over a quarter of a million geochemical measurements of concentrations of potassium, thorium and uranium in soils and in stream sediments to estimate outdoor gamma-ray dose rates across Great Britain. The soil concentrations are generally at a depth of 5–20 cm with some at 35–50 cm. Soil measurements will give spatially relatively precise estimates, but as soil data are not available for much of Scotland, stream sediment data are used there. Kriging methods are used to estimate surface concentrations of K, Th and U and dose rates are imputed from these concentrations. Our results are compared with measurement surveys of both outdoor and indoor gamma-ray dose rates. Recently there has been interest in exploring the carcinogenic risks of low dose radiation by investigating associations between childhood cancer rates and doses from natural background gamma radiation. To achieve adequate statistical power, such studies must be so large that it is impractical to assess exposures by direct measurements in the homes of study subjects. Instead the exposures must be modelled. The results presented here will be an important input to such work.

Assessment of Background Gamma Radiation Level in Selected Dump Site of Niger Delta, Nigeria

Our environment has been exposed to ionizing radiation from indiscriminate dumping of refuse which is seen as unending and unpreventable challenge on earth. Radiation level and exposure risks in some selected dump site in Rivers state have been calculated using radiation exposure rate meter (Radalert-100). Rate of exposure measured at Ignatius Ajuru University of Education (IAUE) and its environment ranged from 0.005±0.0001 to 0.016±0.003 mRh-1 with mean value of 0.015±0.002 mRh-1 and that measured at Igwuruta ranged from 0.009±0.001 to 0.048±0.003 mRh-1 its mean value is 0.015±0.002 mRh-1. For All, the exposure rate measured ranged from 0.009±0.0001 to 0.015±0.002 mRh-1 its mean value is 0.012±0.004 mRh-1. The exposure rates measured in the three dump site are relatively equal and slightly higher than the recommended permissible limit of 0.013 mRh-1. Estimation of the mean absorbed doses from the exposure rates for Ignatius Ajuru University of Education, Igwuruta and Aluu are 127.72±31.26, 125.91±18.35 and 175.64±41.61 nGyh-1 respectively, its mean absorbed doses are 1.16, 1.18 and 1.11 mSvy-1 respectively. The annual effective dose equivalent calculated is 0.20±0.03, 0.19±0.03 and 0.19±0.03 mSvy-1. The excess lifetime cancer risk estimated ranged from 0.68±0.11, 0.68±0.10 and 0.68±0.10 respectively, they are all above the recommended values 0.29x10ˉ3 in all the sampling locations. Following the result from the radiation level of the dump site, no immediate radiation risk is expected, but there could be a long term effects on those living around the dump side.