Operational Intervention Levels (OILs) are a part of the emergency preparedness and response program, which must be established during the preparedness stage. OILs are operational criteria that can be used promptly, without further assessment to determine the appropriate protective actions or other response actions based on environmental measurement or laboratory analysis. International Atomic Energy Agency (IAEA) provided a set of spreadsheets to support Member States in determining the default OIL values based on their facilities specific data. In this study, these spreadsheets are utilized to calculate specific time-dependent OIL(t) functions for a 30 MW research reactor RSG-GAS. Time-dependent OIL(t) calculation considers ten elements including generic criteria proposed by IAEA and RSG-GAS source term data for beyond design basis accident (BDBA) computed in previous study. Based on the time-dependent OIL(t) calculation results, facility site condition, limited resources, and any other specific conservative consideration, it can be concluded that some of the IAEA’s default OILs values must be revised before used as operational criteria in case of RSG-GAS accident.

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Background: The use of thermoplastic immobilization devices in radiotherapy increases the positional repeatability of irradiation. However, these devices act as boluses and increase surface dose. In this study, we evaluated the increase in surface dose using seven types of thermoplastic immobilization products.
Methods: Seven types of products were cut to a size of 5×5 cm2 and stretched by 5 cm in two directions. The surface dose was measured using Gafchromic EBT3 films placed above a 20 cm stacked water equivalent phantom, and the source surface distance was 100 cm. Subsequently, the shells were placed on a film. The films were then irradiated with 200 MU of 6 MV X-rays. Theirradiated films were scanned after 24 h and converted to the absorbed dose using a density-dose conversion table.
Results: The surface dose with no stretch shells was 2.9–fold higher than that without shells. Among the seven products, the maximum and the minimum increase were 3.2– and 2.6–fold, respectively. Meanwhile, the 5 cm stretched shells increased the surface dose by 2.3–fold (max: 2.7–, min: 1.9–fold). The increase in the surface dose decreased with the degree of shell stretch (2.5, 5.0, and 7.5 cm). In addition, the pore size and pore area per cm2 showed a negative correlation with the relative dose increase from without shells (r = -0.66 and -0.69, respectively).
Conclusions: Product dif ferences in dose increase were small, suggesting that pore size and pore area per cm2 are important. Meanwhile, stretch effectively reduce the surface dose increase; however, care must be taken to balance the extent of stretch with the stiffness.

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In the radon prone area of the Adamawa region in Cameroon, most of the dwellings are built with locally made mud bricks. The contribution of this building material to the inhalation dose was assessed using the RESRAD Build software. Assuming the indoor occupancy factor of 0.6, the related dose is found to be 0.8 mSv y^-1 corresponding to 14% of the total inhalation dose. Thus, the contribution of the used building material to the inhalation dose in this radon prone area is not negligible.

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An alternative method to dose estimation in cytogenetic biodosimetry is the cytokinesis-block micronucleus (CBMN) assay. Similar to the dicentric chromosome assay, this method correlates micronuclei formation in binucleated cells with absorbed dose. Instead of colcemid to arrest cells transiting from metaphase to anaphase, cytochalasin B is added to dividing human peripheral blood lymphocytes for cytokinesis inhibition. In this series, the history, applications, and recent developments of the CBMN assay in the context of cytogenetic biodosimetry are discussed. The topics covered include cell culture techniques, harvest and fixation processes, cell staining, imaging methodologies, micronucleus scoring criteria and procedures, and dosimetry applications. This review aims to provide insights into the various aspects of the CBMN assay, highlighting its significance and potential improvements for precise dose estimation in radiation exposure scenarios.

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Ionizing radiation is ubiquitous and constitutes the primordial environment for human beings on Earth. With advancements in technology, the average radiation dose per capita has been steadily increasing. According to estimates from the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the current average annual dose received by an individual from natural sources is 2.24 mSv, while artificial sources, primarily from radiological diagnostics, contribute an additional 0.6 mSv. Among natural sources, the focus is primarily on indoor radon concentration and its dose trends, as well as its attributable contribution to lung cancer. In terms of artificial sources, the emphasis is on occupational exposure received by workers and the medical exposure associated with radiological diagnostics especially CT scanning for a large number of patients.
 In the field of occupational exposure, there are about 75,300 radiological diagnosis and therapy institutions, including more than 30,000 hospitals and over 30,000 township health centers and some specialized health/medical institutions, employing approximately 520,000 radiation workers across various disciplines such as radiological diagnostics, interventional radiology, nuclear medicine, and radiation therapy. Additionally, the industrial sector comprises over 16,000 radiation work units and more than 200,000 radiation workers. The nuclear industry also employs a significant number of radiation workers.
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This presentation is about the education and career path of Dr. Valerie Goh, a Research Fellow in the Singapore Nuclear Research and Safety Initiative (SNRSI). She graduated with a Bachelor’s degree in Biological Sciences from Nanyang Technological University, Singapore. With an overseas postgraduate scholarship from SNRSI, she graduated with a Master’s and PhD from Hirosaki University, specializing in cytogenetic biodosimetry. She is now working in the Department of Radiobiology in SNRSI, focusing her research on the application of cytogenetic biodosimetry in emergency radiation response.
 Future aspirations in Singapore include developing Singaporean-focused dose-response curves and protocols for cytogenetic biodosimetry, improving collaborations with hospitals and communicating with relevant government departments for biological dosimetry. In addition, international exposure through continued participation in conferences and inter-laboratory comparisons will help to strengthen interactions between international research groups, especially with ASEAN members within Southeast Asia.
 She will also present about her personal journey of choosing radiation biology research as a career and to showcase the different areas of her research group’s work in SNRSI. This presentation also aims to show that having a relevant education background might not be important, though encouraged, as skills can be transferrable to dif ferent specializations. Furthermore, other than cytogenetic biodosimetry, other areas of radiation biology can also be researched on, such as the study of bystander effects, effects of low dose and low dose-rate radiation and epidemiology.

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The results of radioactivity measurements in the environment are mainly used for dosimetric purposes. However, knowing the exact concentration of different radioactive isotopes can help us to understand the world around us. The concentrations of Ra-226, Pb-210 can be used to study the effects of the last 200 years, e.g. by studying the sediments of lakes, we can trace the ef fects of anthropological activity on nature^{1, 2)}.
 By studying the ratios of different artificial isotopes, we can find out the properties of nuclear accidents and explosions. By measuring the isotopes released into the atmosphere, we can determine the location and radiological properties of contaminating sources³⁾. By studying different plants, fungi and animals, we can better understand nature’s response to the effects of radiation⁴⁾.

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No dose-response model has yet been developed or is likely to be in the foreseeable future which, for radiation protection purposes, can adequately describe the health effects due to radiation exposure across all radiation types, dose and dose rate ranges, organ and tissue types and time scales. All existing models have their limitations in these regards. Accordingly international organisations concerned with radiation protection, such as ICRP, WHO,IAEA etc have for pragmatic reasons adopted a Linear No Threshold (LNT) dose-response model as a basis for formulating their radiation protection policies and setting regulatory dose limits. The LNT model postulates that all exposures to ionizing radiation down to zero dose are harmful. It therefore considers that there is no universal threshold dose below which there is no risk of radiation related cancer. The model is, however, often misused to estimate the carcinogenic effects of collective doses from low-level radioactive contamination of the environment. This practice, which is explicitly discouraged by the ICRP, contributes to increased public radiophobia and has led to actions by authorities in radiation emergencies which were clearly not consistent with the Principle of Justification. The use of the LNT model at doses above 100 mSv has, however, for many years afforded an acceptable level of protection in both occupational and public exposure situations. However at low doses (‹100 mSv) the validity of its use has been a source of ongoing dispute and debate in the radiation protection community. In this presentation an account is given of the historical background of the LNT model as well as why its use at low doses has been controversial. A major issue in the LNT model debate is whether it is scientifically possible to determine if there is a universal dose threshold. A resolution of this issue may take many years to resolve if indeed it is ever fully resolved. Based on current knowledge if a threshold dose does exist it most likely will be at a level of a few tens of mSv at most. At such a level of dose the associated fatal cancer risk would be very much lower than the general risk of cancer in many populations making it very difficult to determine. It might therefore be appropriate for authorities and policymakers to adopt a pragmatic operational threshold (say in the range 10 - 50 mSv). Below such a level, in keeping with the Principle of Justification, protective actions in an emergency for example might not be considered justified from both a total health and a socio-economic perspective. Discussion of the merits and demerits of this suggestion in the radiation protection community might be worthwhile.

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Gadolinium (Gd)-based contrast agents (GBCAs) are commonly used to enhance magnetic resonance imaging (MRI) to increase the diagnostic yield. Although severe adverse ef fects of GBCAs in offspring when administered during pregnancy or lactation have not yet been reported, the tissue retention of total Gd after GBCAs exposure has been detected in the skin, liver, kidney, lung, heart, bones and brain. In the central nervous system, Gd retention has been observed in various brain regions, including the hippocampus, cerebellum, dentate nucleus, and globus pallidus. Considering the fact that blood-brain-barrier is not complete during pregnancy and lactation, it is reasonable to speculate that Gd retention may be greater if fetus and/or newborn are exposed to GBCAs during such periods. However, the ef fects of fetal/neonatal GBCA exposure on brain function and development have not yet been fully studied. Our group examined the effect of GBCA exposure using in vivo (mouse) and in vitro preparation. GBCA was detected from offspring brain after perinatal exposure, and in breast milk. Perinatal GBCA exposure disrupted motor coordination and spatial memory with decreased expression of several AMPA and NMDA receptor subunits. In astrocyte culture, GBCA accelerated cellular migration by modulating actin rearrangement through activating integrin α vβ3. In primary cerebellar culture, GBCA increased thyroid hormone-activated Purkinje cell dendritic arborization. Furthermore, GBCA augmented ligand-dependent thyroid hormone receptor-mediated transcription. These results indicate that perinatal GBCA exposure may disrupt brain development at least in part through disrupting integrin α vβ3-mediated and/or thyroid hormone receptor mediated pathway. The use of GBCAs in pregnant and lactating women may be avoided unless absolutely necessary.

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We are required the distribution of radioactivity in the building to proceed with the decommissioning of TEPCO’s Fukushima Daiichi Nuclear Power Plants. Therefore, we developed and evaluated a compact and portable omni-directional radiation detector (FRIE) which can be used in high-dose environment. FRIE arranges the scintillators in the Sierpinski’s tetrahedron shape which is fractal shape. Combined with the FRIE’s counting rate and Maximum Likelihood Expectation Maximization method, the radioactivity distribution can be imaged in three-dimensions. In this study, we evaluated the accuracy of the radioactivity distribution estimation by simulation when random errors were introduced to the measurement positions. The radioactivity distribution was also imaged threedimensionally by a laboratory test using ¹³⁷Cs sources. As a result, it was found that the source position can be measured with almost no error if the measurement position error is within 0.2 m. It was also possible to determine the location of the sources and estimate the approximate radioactivity intensity of the sources after only a few minutes of measurement.

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A simple model for determining radon exhalation rate from soil was reported with the emanation coefficient as a critical parameter. Despite numerous estimates of radon emanation coef ficients, methodologies for experimental var y among researchers, and a standardized approach for laboratory experiments is lacking. The purpose of this research is to develop a suitable method for the estimation of the radon emanation coefficient in a laboratory environment. The radon emanation coefficient was calculated from the activity concentration of radon (²²²Rn) in an accumulation chamber (internal volume: 6.7 L), obtained by the circulation or grab sampling method, and the radium (²²⁶Ra) activity concentration in the soil samples. The dark red soil and the weathered granite soil collected in Okinawa and Gifu Prefectures, respectively were used in this study because these samples had relatively high ²²⁶Ra activity concentrations to reduce the measurement uncertainty. It was found that the uncertainty of the leakage rate observed by the circulation method was greater than that observed by the grab sampling method. Therefore, we decided to use the grab sampling method to determine the radon emanation coef ficient. In addition, we carried out the laboratory xperiments to evaluate the influence of soil sample thickness on the determination of radon emanation coef ficient. The radon emanation coefficients were stable up to 3 cm, then decreased as soil sample thickness increased. This result is possibly attributed to the balance between the changing concentration gradient of radon atoms and the adsorption of radon atoms on the soil particle surface and/or in the pore space of the soil particles.

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The conversion factor (CF) from track density (Ti) of CR-39 to exposure to radon progeny for the passive-type radon progeny monitor (progeny monitor) was determined theoretically (5.0×10⁵ track mm^-2 per J m^-3 day)¹⁾. In this study, calibration experiments for the progeny monitors were performed in the radon exposure chamber and indoor environments, a hot spring facility in Hokkaido, and a dwelling in Aomori. The progeny monitors and a Portable Environmental Radiation/Radioactivity Monitor (PERRM) were installed at each site. After the measurements, CFs were calculated based on Ti and potential alpha energy concentration (PAEC) obtained by the progeny monitors and PERRM, respectively. As a result, CFs ranged from 1.4 × 10⁶ to 15 × 10⁶ track mm^-2 per J m^-3 day depending on the experimental sites. This study suggested that CF should be characterized and a suitable CF should be related to environmental conditions, such as an unattached fraction of radon progeny, aerosol conditions, etc. Therefore, it is necessary to evaluate CFs with these conditions in further studies.

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Air filters are widely used to collect ambient radioactive aerosols at nuclear facilities. In the measurement of alpha-emitting radionuclides, the surface collection ef ficiency (SCE) is crucial for filter selection because their collection inside the filter matrix causes the energy spectrum degradation. However, SCEs reported in previous studies varied depending on methods, even for the same filters. In this study, the SCEs evaluated by the conventional methods were examined using Monte Carlo simulations. Radon progeny in a radon exposure chamber was collected on filters, and the SCEs for the filter were calculated by applying the conventional methods to its alpha energy spectrum measured using a silicon semiconductor detector under vacuum conditions. The SCEs were also evaluated by adjusting the alpha energy spectrum simulated using a particle and heavy ion transport code system (PHITS ver. 3.02) to the measured spectrum. As a result, one of the three conventional methods provided the best estimate of SCEs for filters, which agreed well with the simulated SCEs. This method shows the lowest SCEs compared to those evaluated by the conventional methods, indicating that the SCEs reported in previous studies may have been overestimated.

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Throughout the COVID-19 pandemic, wearing a mask has gained prominence as a preventive measure against the virus infection. It may possibly reduce inhalation exposure to radon (²²²Rn) progeny aerosols, which is a second risk factor for lung cancer. The effectiveness of three types of facial masks was evaluated in reducing radon exposures.
 The results showed that the collection ef ficiency (CE) of radon progeny aerosols for the N95 mask was over 96% throughout the examined flow rate range. The CE for surgical masks exceeded 96% at the typical flow rates equivalent to the breathing rate during sedentary or light exercise and decreased to approximately 88% at 7.2 L min^-1. For the nylon mask, the CE was approximately 50% at sedentary flow rates and significantly decreased with increasing the flow rate. The N95 mask and surgical mask were highly effective in reducing inhalation exposures, while the nylon masks or stylish masks had about half the effectiveness of the others and depended on the breathing rate.

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We are currently developing a rod-shaped surface contamination monitor designed for measuring contamination on the inner surfaces of pipes. In this study, a prototype detector consisting of a 200 μm thick plastic scintillator enveloping a 200 mm long acrylic bar was employed. To investigate response variations along the entire length of the prototype rod-shaped monitor, a novel apparatus capable of reproducibly altering the source-to-detector geometry was developed and utilized. For the test, sources with ⁶⁰Co on the inner wall of the carbon steel (SS400) or acrylic pipe were used. The test was conducted in three distinct conditions. (I) The positional dependence of sensitivity along the long axis was evaluated by performing a set of measurements at five dif ferent points, each 30 mm apart, starting from the detector’s tip. A 30 mm long ⁶⁰Co SS400 pipe source with an internal diameter of 21.6 mm was used. The sensitivity was highest at the terminal end, 37% above the average of the five positions, while the sensitivities at the remaining positions, excluding the tip, were within ±10% of the mean. (II) Using the same source as in Test (I), the detector was positioned both at the axial center of the source and as far off-center as possible. The response at the off-center position was 5.2% higher than at the center. (III) A 150 mm long ⁶⁰Co acrylic pipe source with 18 mm inner diameter was used. The detector was tilted at an angle of 2.2° inside the pipe source during measurements, resulting in a 9.5% decrease in response compared to the central position.

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Internal exposure caused by the inhalation of radon is well known as the second leading cause of lung cancer¹⁾. Thus, measuring radon concentration is essential to prevent damage to human health. Nowadays, a radioiodine sampler is used to monitor the environment around nuclear facilities. The activated carbon stored in the sampler’s cartridge can absorb both radioiodine and radon due to its adsorptivity. In this study, we evaluated the usefulness of the radioiodine sampler for measuring radon concentration. Air sampling was conducted for 1 hour under stable radon concentration, and gamma rays from radon progenies trapped in the cartridge were measured hourly for 25 hours using a highpurity germanium (HPGe) detector. As a result, each conversion factor calculated with the net counting rate measured 4 hours after sampling showed consistent values. The detection limit was evaluated as 0.1 Bq m^-3, which is lower than the Japanese average indoor and outdoor radon concentrations: 15.5 and 6.1 Bq m^-3, respectively²⁾. Therefore, radon concentration can be evaluated by a 1-h air sampling using the radioiodine sampler, a 4-h waiting time, and a 1-h measurement using the HPGe detector.

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²²³Ra is one of the α-emitters utilized in cancer therapy. α-spectrometry using a Si detector is used for primary standardization due to its superior energy resolution. In this study, the measurement of ²²³Ra, which undergoes multiple α and β decays, was conducted using a large-area Si detector with a close detector-source geometry to investigate its effectiveness as a 2π α detector. For this study, 0.1 N-HCl solutions of ²²³Ra were used. Approximately 30 mg of each solution and 10 mg of Ludox, diluted 10⁴ times were deposited onto a plastic plate and dried to prepare solid sources. Measurements were carried out using an ion-implanted Si detector (AS2000V, SARAD^®). The source-detector distance was 1 mm, and the absolute pressure in the vacuum chamber was kept below 40 Pa. The measured spectra exhibited a degradation in energy resolution. The FWHM of ²²³Ra was approximately 260 keV, whereas the FWHM of α -particle emitted from an ²⁴¹Am source with a collimator was 40 keV1). The α -particle peaks overlapped, precluding their separation. In order to analyze the multiple components within the overlapping peaks, α - γ coincidence spectroscopy was applied. The coincidence spectra were generated from list-data using custom-made software. As a result, distinct α -particle lines emitted from ²²³Ra, ²¹⁹Rn and ²¹¹Bi could be separately observed. The present result suggests that such a large-area Si detector might be useful in determining the individual activities of ²²³Ra and its progenies with a 2π geometry measurement.

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Estimation of internal radiation doses due to radon/thoron inhalation was carried out in Fukushima-Japan, and Thailand. A passive monitor (RADUET) developed by Tokonami et al.¹⁾ was used to measure radon and thoron. The RADUET was settled in the rooms of high school students and an university student for four months. The estimated radiation doses from RADUET system were 0.53±0.08 mSv/year in the rooms of Thai students (n=3) and 0.25 mSv/year in the room of university student in Fukushima. The results showed that the radon/thoron internal radiation doses in Fukushima and Thailand were not significantly different.

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This study investigates the soil properties in a coffee field of the Agricultural Innovation Research, Integration, Demonstration and Training Center (AIRID), Chiang Mai, Thailand. By sampling the soil samples at 0–30 cm and 30–60 cm depths at ten dif ferent points, the research analyzed changes in key soil parameters such as pH, organic matter content, and nutrient availability before and after applying the fertilizer to the soil. The findings indicate that there was a slight increase in soil nutrient levels, and the marginally change in its pH, and organic matter content. Variations in temperature and precipitation play a significant role in influencing these changes¹⁾. The study underscores the importance of considering both fertilizer use and environmental conditions in managing soil health for coffee cultivation in the region.

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The Organically bound tritium (OBT) is one of the most difficult radionuclides to analyze through radiometry. In particular, the combustion process for exchanging from organic material to HTO requires skilled techniques. To make the operation simple, safe and reproducible, a semi-automatic combustion system was developed. In general, tritium concentrations in the environment are low. However, there is a report that tritium concentrations have been detected in precipitation in highlatitude areas of Japan¹⁾. In this study, lake fish collected from Shikotsu Lake at Hokkaido were sampled and the OBT was analyzed by the developed system. The result showed that the OBT concentration was just barely detectable by the liquid scintillation counter.

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Radon (²²²Rn) is a ubiquitous radioactive gas that comes from the decay of ²²⁶Ra as part of the ²³⁸U decay chain, one of the naturally occurring radioactive materials (NORM). Radon, radium, and uranium are soluble in water and can be found in various concentrations in groundwater. Human activity, such as mining, can elevate NORM in the environment. Additionally, by-products of tin smelting (tin-slag) that contain high concentrations of NORM might leach radon and ²²⁶Ra into the groundwater. This study aims to investigate the radon concentration in the water found in the tinmine area of Sungai Liat and Pangkal Pinang, Bangka Island, Indonesia. Six surface water samples were collected from the ex-tin mine pond, and twenty groundwater samples were collected from the nearby well. For each, 10 mL of water sample were injected into 10 ml of mineral oil scintillator inside a 20-mL glass vial. The integral counting method by portable liquid scintillation counter (Triathler, Hidex) was used to measure the radon concentrations in the samples. The radon concentrations in the ex-tin mine ponds ranged from 31 Bq L^-1 to 75 Bq L^-1. The measured radon concentration in the wells ranged from 48 Bq L^-1 to 129 Bq L^-1. The highest and second highest radon concentration in groundwater were found in the sample closest to a tin-slag storage and ex-tin mine pond, respectively.

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Various natural radionuclides exist naturally in the environment, but their distribution is uneven, when these radionuclides enter drinking water, they can enter the food chain and potentially increase radiation exposure for people¹⁾. Five springs, located along popular hiking routes and tourist destinations in Veszprém County were selected for investigation. The primary aim was to examine how different sample preparation parameters affect the measurement of Ra-226. During sample preparation, the study explored potential optimizations based on the BS ISO 13165-1:2013 standard. The samples were adjusted to various pH levels. After acidifying the samples, the effect of vaporization temperature (80˚C and 100˚C) was analysed. Additionally, by increasing the sample volumes (200, 300, 400, and 500ml), the impact of heat treatment duration on the concentration ratio (1:10) was assessed. Salt precipitation was observed during evaporation at 80˚C in samples with natural, 5, and 6 pH. At 100˚C, precipitation occurred even in samples with a pH of 4. ProScint Rn A/B scintillator cocktail and a TriCarb 3170 TR/SL Liquid Scintillation Counter were used, with a detection limit of 100 mBq/L. None of the samples exceeded the activity concentration of 200 mBq/L, indicating that their consumption does not pose a significant radiological risk.

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Discharge of treated water including tritium from the Fukushima Daiichi Nuclear Power Plant (FDNPP) had begun since August 2023. To understand the regional background level for public concern of tritium, river water samples were collected at upstream and downstream at Ukedo River located through Namie Town, and measured tritium concentration. As the results, tritium concentration at upstream during April 2021 to April 2024 ranged from 0.27 to 0.52 Bq/L, and the average concentration of 2022-2023 was 0.38±0.06 Bq/L. Those of downstream during October 2021 to April 2024 ranged from 0.26 to 0.59 Bq/L, and the average concentration of 2022-2023 was 0.39±0.10 Bq/L. There was no clear seasonal variation at both sites. It has been reported that the range of tritium concentrations in precipitation in the Tsushima area from October 2012 to December 2021¹⁾. Our result of average tritium concentration in Ukedo river water was comparable to the those of average tritium concentration in precipitation at upstream area.

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The radiation exposure from the tin processing in Bangka is a primary concern in radiation protection, as it could be a major source of chronic radiation exposure in the surrounding community, especially the workers. This ongoing research focuses on the workers directly involved in industrial processes. This study aims to understand the relationship between the ambient dose rate and Naturally Occurring Radioactive Material (NORM) and elemental concentration in tin processing. Samples were obtained from raw material to byproducts in that industry. The major, trace, and radioactive elements were analyzed by using X-ray fluorescence (XRF). The results show that the concentrations of U and Th were <0.005% to 2% and <0.008% to 4%, respectively. This study revealed a clear relationship between the ambient dose rate and the highest NORM concentration during the melting process, highlighting the potential health risks associated with chronic radiation exposure.

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Since 2019, Indonesia has integrated the United Nations Sustainable Development Goals (SDGs) into its national development strategy, with one of the focuses is on healthcare and scientific research through nuclear science and technology. This includes the establishment of nuclear facilities for research and medical purposes. This expansion requires a thorough understanding of public perceptions of radiation risks for people living near the facilities. Our study aims to assess and improve community awareness and preparedness through radiation risk communication. As an initial study, we conducted a survey using 100 questionnaires distributed to residents living near nuclear facilities, complemented by the installation of passive radon monitors and environmental measurements. Our results show significant gaps in public awareness and preparedness. For example, 53% of respondents were unaware of ionising radiation and expressed negative feelings and concerns about its effects. These knowledge gaps and misconceptions highlight the need for more targeted and comprehensive risk communication strategies, taking into account community demographics, to improve public understanding of the risks of radiation exposure and enhance preparedness.

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The quality of indoor air and its ef fects on residents’ health have become an increasing concern in recent years. Among the critical sources of indoor air pollution is radon, known as the second leading cause of lung cancer after smoking¹⁾. In this study, radon concentrations were measured for the first time in 50 homes in Safi city, Morocco, using LR-115 detectors. The annual effective dose and Excess Lifetime Cancer Risk were also estimated. The measured radon concentrations ranged from the Limit of Detection to 132 Bq.m^-3 with an arithmetic mean of 53 Bq.m^-3. The results indicated that 58% of the obtained values exceeded the global average (39 Bq.m^-3). Inhabitants of the surveyed houses were found to receive a mean annual effective dose of 1.5±0.1 mSv.y^-1, corresponding to an Excess Lifetime Cancer Risk of 0.6%. Importantly, all annual effective dose values remained below the ICRP action level of 3-10 mSv.y^-1. An indoor radon distribution map was generated using the Ordinary Kriging, based on the collected data.

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The Semipalatinsk Test Site (STS) features a variety of water sources, most of which have been af fected by radioactive contamination. Presently, local farmers use these water sources for agricultural purposes, particularly for watering livestock. There are instances of fish being caught in the vicinity of STS area for personal consumption and for sale in adjacent communities¹⁾. The carp (Cyprinus carpio), roach (Rutilus rutilus) samples were collected from the Shagan River around of the STS territory. Pretreatment of the samples were combusted or leached in concentrated HNO₃ was used, with H₂O₂ added as necessary. The ¹³⁷Cs were measured by gamma spectrometry, the actinides were quantified using alpha spectrometry, while ⁹⁰Y’s activity were measured by LSC counter. The determination of ⁹⁰Sr was based on its decay product, ⁹⁰Y. The results of ¹³⁷Cs, ^239+240Pu activities in muscle was 0.14-2.6 Bq/kg, 0.031-0.81 Bq/kg respectively. The ⁹⁰Sr concentration was under the detection limit. Based on our result the activity concentrations consumption of these fishes doesn’t cause significant radiation dose for the population.

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This study was carried out to collect the background level of tritium concentration data before treating water was released which the Japanese government and TEPCO have decided to discharge since August 2023. Seawater samples were collected in July 2022 from 11 locations, ranging from equatorial to subtropical regions in the western North Pacific, during the R/V Hakuho-maru KH-22-7 cruise. Tritium concentrations were measured by the ultra-low level counting method with attained an enrichment factor of 14.93. The detection limit of this method was approximately 0.02 Bq/L and the range concentration of tritium ranged from 0.02 to 0.12 Bq/L with mean value 0.06 ± 0.03 Bq/L. According to Kaizer et al. (2018)¹⁾ tritium levels in the western North Pacific post-Fukushima accident were measured from seawater samples in the winter of 2012, it was found the surface tritium concentration of 0.24 ± 0.01 Bq/L in the subtropical zone which is higher than the levels observed in this study. This data is significant for comparing the tritium concentration after the discharging, whether it is released from nuclear power plants or nuclear-reprocessing plants.

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Biological effects result from physical interactions and chemical reactions to DNA in the human body. The indirect effects of chemical products (e.g., •OH, e‾ _aq, H₂, and H₂O₂) resulting from water radiolysis are believed to be about 70% in total. In this study, we developed a chemical simulation code coupled with a general-purpose Monte Carlo simulation code, Particle and Heavy Ion Transport code System (PHITS)¹⁾ for evaluating biological impacts in radiation therapy. First, to simulate each atomic interaction, we used track-structure simulation models, i.e., electron track-structure (PHITSETS) and ion track-structure (PHITS-KURBUC and ITSART), as physical stage simulation. Second, we developed the chemical code dedicated to PHITS, named PHITS-Chem code, and simulated the dynamics of chemical products based on the spatial coordinates of atomic interactions. The simulated time-dependent yields of chemical products were compared to the values reported in the literature²⁾. As a result, we confirmed that the developed PHITS-Chem code could successfully reproduce the time-dependent G values of ion beams, so far. Focusing on the OH radical yield, further simulation work is being carried out to discuss the biological impacts.

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Targeted isotope therapy (TRT) is a type of radiation therapy that uses radioactivity to target and eradicate cancer cells specifically. However, the biological effects after the internal irradiation with α emitters remain uncertain. In this study, we investigated the microscopic dose and the subsequent biological impacts using a Monte Carlo code (i.e., Particle and Heavy Ion Transport code System, PHITS) and a biophysical model (i.e., integrated microdosimetric-kinetic (IMK) model). First, we used the PHITS code to calculate the microdosimetric quantity of lineal energy (y keV/μm). Second, using the dose-mean lineal energy y_D value, we estimated the relative biological effectiveness (RBE) values using the IMK model. Third, we compared the estimated RBE values to the experimental RBE as a function of LET in V79 cell lines. After that, we investigated the curative effects using ²¹¹At α emitter. As a result, using the calculated y_D values, we could successfully reproduce the experimental LET-dependence of RBE value in V79 cell lines. Particularly, the estimated RBE values of carbon and neon beams at about 200 keV/μm of LET were found to be maximal. As for the ²¹¹At α emitter, the LET and the estimated RBE value were 113.7 keV/μm and 5.04 ± 0.78, respectively. The estimated RBE value reasonably agreed with the corresponding experimental data reported in the literature. Further studies for heterogeneous uptake are required in future studies.

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Boron neutron capture therapy (BNCT) is unique radiotherapy in that it uses short-range heavy ions emitted by the ¹⁰B(n,α )⁷Li reaction, which can selectively eradicate cells that take up tumor-seeking ¹⁰B compounds. Boron compounds are expected to be heterogeneously taken up at the cellular level; however, the biological impacts remain uncertain. In this study, we investigated the uptake fraction of boron (i.e., p-boronophenylalanine, BPA) and its biological ef fects using Monte Carlo simulation code (i.e., Particle and Heavy Ion Transport code System (PHITS)) and a biophysical model (i.e., modified microdosimetric-kinetic (MK) model). We generated the experimental data of averaged uptake fraction for the boron concentrations within the HeLa cell line series (including HeLa-FUCCI) after the administration of 20- and 200-ppm BPA¹⁾. Note that the boron concentrations inside the cells have been measured by a CR-39 detector and PHITS, as reported previously. Herein, we estimated the mean relative biological effectiveness (RBE) of the HeLa cell line series based on the conventional MK model without considering cell-cycle dependence. The experimental analysis coupled with CR-39 and the PHITS code revealed that the uptake fractions of BPA for 20-ppm and 200-ppm administrations were about 37.3% and 13.9%, respectively. The RBE values estimated using the measured BPA for 20-ppm and 200-ppm administrations were 2.21 and 2.66, respectively. Meanwhile, the mean RBE values for 20 ppm and 200 ppm assuming the full uptake were 2.53 and 3.36, respectively. Such insufficient boron uptake plays a key role in determining the curative effects.

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In our study we determined the massic Rn-222 exhalation rate and emanation factor of soil samples from a western region of Hungary, Transdanubia. 145 samples were collected in the vicinity of populated settlements in Hungary¹⁾, because our study serves as a complementary measurement of the currently implemented National Radon Action Plan, the aim of which is to investigate the radon exposure of the public, required by the European Union²⁾. Our study is independent of legal requirements.
 The aim of the work was to investigate the regional occurrence of Rn-222 from soil by the processed samples, to analyse the results and to detect possible local hotspots, which can be used for further measurements to determine the radiation exposure of the population²⁾.
 The massic radon exhalation results ranged from 1.02 mBq/kg × h to 275.63 mBq/kg × h. The obtained emanation factor results ranged from 0.01 to 0.79³⁾.

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In Northern Kazakhstan, there are uranium processing facilities, depleted uranium mines, and radioactive waste storage facilities. The project goal is to investigate the impact of technogenic radiation factors on the development of tumor and non-tumor bronchopulmonary diseases in the population of Northern Kazakhstan based on molecular-genetic analysis. Based on the obtained data on the radioecological situation, probable dose load will be calculated, and the risk of bronchopulmonary diseases in the population will be assessed. For the first time, the presence of polymorphisms in genes ERCC1 (rs11615, rs3212986), ERCC2 (rs13181), OGG1 (rs1052133), ABL2 rs117218074, SMARCA4 rs2288845, PIK3R2 rs142933317, MAPK1 rs1803545, (CHD4) rs74790047, and TSC2 rs2121870 will be studied in lung cancer patients exposed to radon, radiation risk factors for development of oncopathology in the population. Considering the synthesis and analysis of study results, measures will be developed to reduce technogenic and radiation risks of bronchopulmonary diseases for the population living near the storage facilities for radioactive waste and decommissioned mines in Northern Kazakhstan.

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Mining sites are regarded as the primary sources of naturally occurring radioactive materials, which increase the risk of radiation exposure to humans in the environment. The World Health Organization reports an increased risk of lung cancer in uranium miners exposed to high levels of radon. To assess public health, this study aims to estimate internal exposures for residents in old tin mining areas. The internal exposures from radon, thoron, and their progeny were measured for 90 dwellings in an old tin mining area in Kanchanaburi Province, Thailand, using a passive radon and thoron discriminative monitor (RADUET) and a passive radon-thoron progeny monitor. This measurement was conducted for a period of four months and repeated three times from March 2023 to February 2024. The indoor concentrations of radon, thoron, radon progeny and thoron progeny ranged from 9 to 79, 4 to 128, 0.04 to 19, and 1.3 to 13.1 Bq m^-3, respectively. The outdoor concentrations of radon, thoron, radon progeny and thoron progeny ranged from 10 to 44, 6 to 37, 2.0 to 4.9, and 1.1 to 7.4 Bq m^-3, respectively. The estimated annual effective dose was 1.9 mSv with a range from 0.4 to 5.4 mSv, exceeding the global value of 1.3 mSv due to thoron and its progeny significantly contributing to the annual effective dose.

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