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This research reviews a novel artificial intelligence (AI)-based application called TLDetect, which filters and classifies anomalous glow curves (GCs) of thermoluminescent dosimeters (TLDs). Until recently, GC review and correction in the lab were performed using an old in-house software, which uses the Microsoft Access database and allows the laboratory technician to manually review and correct almost all GCs without any filtering. The newly developed application TLDetect uses a modern SQL database and filters out only the necessary GCs for technician review. TLDetect first uses an artificial neural network (ANN) model to filter out all regular GCs. Afterwards, it automatically classifies the rest of the GCs into five different anomaly classes. These five classes are defined by the typical patterns of GCs, i.e., high noise at either low or high temperature channels, untypical GC width (either wide or narrow), shifted GCs whether to the low or to the high temperatures, spikes, and a last class that contains all other unclassified anomalies. By this automatic filtering and classification, the algorithm substantially reduces the amount of the technician's time spent reviewing the GCs and makes the external dosimetry laboratory dose assessment process more repeatable, more accurate, and faster. Moreover, a database of the class anomalies distribution over time of GCs is saved along with all their relevant statistics, which can later assist with preliminary diagnosis of TLD reader hardware issues. [ABSTRACT FROM AUTHOR]

This study developed predictable exposure scenarios for thorium-containing gas mantles throughout their life cycle, considering their usage status in the Republic of Korea, and assessed the radiation dose for each scenario. Our results showed that radiation doses in various scenarios, including transport, distribution, usage, and disposal, as well as in low-probability accident scenarios, consistently remained below the regulatory exemption standards set by the International Atomic Energy Agency. Therefore, we concluded that the exemption regulation for the gas mantle is valid under current circumstances in the ROK. [ABSTRACT FROM AUTHOR]

The transport and transfer of radionuclides in the ecological environment (referred to migration) have long been of a particular concern in the field of radiological environmental protection. This paper systematically reviews the current relevant research statuses on mechanisms, models and parameters of radionuclide migration in the ecological environment, and the methods for assessing doses of humans and non-human species, as well as the non-equilibrium migration models and parameters of radionuclide migration in case of accident at a nuclear facility. From multi-dimensional perspectives, such as computational models, evaluation methods, and parameters, etc., this paper explores the transport and transfer behaviors of radionuclides in the ecological environment. In terms of radionuclide migration, this paper systematically reviews the transport processes and migration models of radionuclides from source term release to atmospheric, terrestrial, surface water (rivers, lakes, etc.), groundwater, and marine environments. It elaborates on the basic theories of radionuclide transport and transfer in the ecological environment, compares the characteristics of different transport modes, and summarizes the transport and transfer behaviors of radionuclides in the ecological environment. In terms of environmental radiation exposure assessment, this paper summarizes both individual-related and source-related evaluation methods, describing the basic methods of environmental radiation exposure assessment. It presents a schematic diagram of the main steps and dose estimation models for assessing the impact of radionuclides released into the environment, and sorts out the methods, evaluation models, and dose assessment software for exposure assessment from the perspectives of both the human and non-human species, domestically and internationally. Moreover, for environmental radiation exposure assessment in case of accidents, this paper takes tritium and 14C as examples to provide an overview of short-term migration, accident exposure assessment, and real-time consequence evaluation and decision support for nuclear accidents. It proposes suggestions for further research in the aspects of radionuclide marine transport, dose assessment models for non-human species, short-term accidental release, and the application of artificial intelligence, to provide scientific basis and technical support for nuclear and radiation emergency response, environmental monitoring, and risk assessment.

This research reviews a novel artificial intelligence (AI)-based application called TLDetect, which filters and classifies anomalous glow curves (GCs) of thermoluminescent dosimeters (TLDs). Until recently, GC review and correction in the lab were performed using an old in-house software, which uses the Microsoft Access database and allows the laboratory technician to manually review and correct almost all GCs without any filtering. The newly developed application TLDetect uses a modern SQL database and filters out only the necessary GCs for technician review. TLDetect first uses an artificial neural network (ANN) model to filter out all regular GCs. Afterwards, it automatically classifies the rest of the GCs into five different anomaly classes. These five classes are defined by the typical patterns of GCs, i.e., high noise at either low or high temperature channels, untypical GC width (either wide or narrow), shifted GCs whether to the low or to the high temperatures, spikes, and a last class that contains all other unclassified anomalies. By this automatic filtering and classification, the algorithm substantially reduces the amount of the technician’s time spent reviewing the GCs and makes the external dosimetry laboratory dose assessment process more repeatable, more accurate, and faster. Moreover, a database of the class anomalies distribution over time of GCs is saved along with all their relevant statistics, which can later assist with preliminary diagnosis of TLD reader hardware issues.

Radioactive elements and their impact on the environment and the food chain, including humans, are a matter of major concern, for which appropriate investigations should be performed. The priority is to examine the concentration of radioactive substances in mineral and bottled spring water. This task aims to analyze the quality of 12 conditioned mineral waters by determining their main radionuclides concentrations, such as 238U, 232Th, and 40K. The identification and the quantification of these radionuclides are carried out by their progeny (except the 40K) by using a NaI(Tl) detector coupled with a multichannel analyzer (MCA) and connected to a computer. The activity measured in all samples varied from 0.95 to 3.38 mBq.L−1 with an average of 1.94 mBq.L−1; from 1.55 to 3.56 mBq.L−1 with an average of 2.46 mBq.L−1; and from 200.68 to 269.19 mBq.L−1 with an average of 236.6 mBq.L−1, for 238U, 232Th, and 40K, respectively. To compare the combined radiological effects of radionuclides present in water, a particular factor Ra(eq) is used. This study showed that the maximum value of Ra(eq) is 27.54 mBq.L−1, which is far below the activity limit of 370 mBq.year−1 set by the Organization of Economics and Development (OECD). Concerning the effective annual dose, the following maximums were measured: 1.61 μSv.year−1, 1.133 μSv.year−1, and 0.925 μSv.year−1 for infants, children, and adults, respectively. These values are even smaller than the dose recommended by the WHO which is 100 μSv.year−1. Regarding the excess lifetime cancer risk index, a maximum of 5.63 × 10−6 is found. This index value is still less than that proposed by James, namely 2.5 × 10−3. Thus, the quality of the studied samples respects the radiological international safety and health limits. [ABSTRACT FROM AUTHOR]

Activity concentrations of naturally occurring radionuclides in soil samples collected during 2013-2018 from different 53 locations around Bhabha Atomic Research Centre (BARC), Visakhapatnam, Andhra Pradesh, India, were determined using high-purity germanium gamma-ray spectrometry. An R and D center of BARC is upcoming at Visakhapatnam, North coastal Andhra Pradesh. The annual effective dose (AED) and the radiation indices from the soil activity were evaluated to generate the baseline data for this area. The average activity concentrations of the naturally occurring radionuclides 238U, 226Ra, 232Th, and 40K in the soil samples studied are 29 ± 8 Bq/kg, 31 ± 1 Bq/kg, 188 ± 2 Bq/kg, and 471 ± 10 Bq/kg, respectively. The concentration of 226Ra and 40K in the collected samples is comparable with the world average concentrations of 33 Bq/kg and 420 Bq/kg, however, 232Th is observed to be higher than the world average of 45 Bq/kg. AED due to external terrestrial radiation from the region studied is in the range the range 0.37 to 2.5 mSv/y with an average of 0.9 mSv/y. The mean radium equivalent activity values for around 70% of the studied samples are lower than the permitted levels of 370 Bq/kg. The mean external exposure index has been determined to be around the safe criterion limit of unity. The mean value of the representative level index Iγ is 2.4. Higher values in some locations are due to thorium in monazite deposits. This report will be useful as preoperational study to evaluate the impact on the environment due to ongoing and future man-made developments. [ABSTRACT FROM AUTHOR]

The purpose of the study is to define the level of combined radiological and chemical contamination from the activities of soil and moss samples collected from the Eastern Black Sea region in Turkey and to assess the risk caused by the environmental radioactivity and chemical pollutants. The gamma, gross beta and gross alpha activities were measured in the soil and moss samples. The 238U, 232Th, 40K and 137Cs activity concentrations in the soil samples were measured in the range of 7.0 and 72 Bq kg-1 for 238U, 8.1 and 86 Bq kg-1 for 232Th, 203 and 1190 Bq kg-1 for 40K and 0.71 to 66 Bq kg-1 for 137Cs. In the moss samples, the 137Cs, 40K, 232Th, and 238U activity concentrations were found in the range of 1.03±0.27-24.23±1.39, 137±7-1340±68, 3.58±0.32-5.93±0.44 and 0.88±0.09-2.25±0.23 Bq kg-1, respectively. Contamination from toxic metals in the soils is categorized into enrichment factor, geoaccumulation risk, potential ecological risk and pollution load index. Co, Ni, As and Pb enrichments were determined in the extreme category in the 6 sampling sites. The pollution load index for the selected metals was found to be greater than 1. The geo-accumulation index in one sampling site showed contamination from heavy to severe levels of arsenic and lead. [ABSTRACT FROM AUTHOR]

The safe evacuation of residents near a nuclear power plant during a nuclear accident is vital for emergency response planning. To tackle this challenge, considering the dynamic dispersion of radioactive materials in the atmosphere and its impact on evacuation routes under different meteorological conditions is crucial. This paper develops a dynamic dose-based emergency evacuation model (DDEEM), which is an efficient and optimized nuclear accident evacuation model based on dynamic radiological dose calculation, utilizing an improved A* algorithm to determine optimal evacuation routes. The DDEEM takes into account the influence of radiological plume dispersion and path selection on evacuation effectiveness. This study employs the DDEEM to assess radiological consequences and evacuation strategies for students residing 5 k m from a Chinese nuclear power plant. Under various meteorological conditions, including the three typical meteorological conditions, random ordered and random unordered meteorological sequences, optimal routes obtained through the DDEEM effectively reduce radiological dose exposure and mitigate radiation hazards. The results indicate that all evacuation paths generated by the DDEEM have a maximum dose of less than 1   m S v . Through simulations, the model's effectiveness and reliability in dynamic radiological environments in terms of radiological consequences and evacuation analysis is verified. The research provides valuable insights and a practical tool for nuclear power plant emergency decision-making, enhancing emergency management capabilities during nuclear accidents. The DDEEM offers crucial technical support and a solid foundation for developing effective emergency response strategies. [ABSTRACT FROM AUTHOR]

In the event of a radiological accident or incident, the aim of biological dosimetry is to convert the yield of a specific biomarker of exposure to ionizing radiation into an absorbed dose. Since the 1980s, various tools have been used to deal with the statistical procedures needed for biological dosimetry, and in general those who made several calculations for different biomarkers were based on closed source software. Here we present a new open source program, Biodose Tools, that has been developed under the umbrella of RENEB (Running the European Network of Biological and retrospective Physical dosimetry). The application has been developed using the R programming language and the shiny package as a framework to create a user-friendly online solution. Since no unique method exists for the different mathematical processes, several meetings and periodic correspondence were held in order to reach a consensus on the solutions to be implemented. The current version 3.6.1 supports dose-effect fitting for dicentric and translocation assay. For dose estimation Biodose Tools implements those methods indicated in international guidelines and a specific method to assess heterogeneous exposures. The app can include information on the irradiation conditions to generate the calibration curve. Also, in the dose estimate, information about the accident can be included as well as the explanation of the results obtained. Because the app allows generating a report in various formats, it allows traceability of each biological dosimetry study carried out. The app has been used globally in different exercises and training, which has made it possible to find errors and improve the app itself. There are some features that still need consensus, such as curve fitting and dose estimation using micronucleus analysis. It is also planned to include a package dedicated to interlaboratory comparisons and the incorporation of Bayesian methods for dose estimation. Biodose Tools provides an open-source solution for biological dosimetry laboratories. The consensus reached helps to harmonize the way in which uncertainties are calculated. In addition, because each laboratory can download and customize the app's source code, it offers a platform to integrate new features. [ABSTRACT FROM AUTHOR]

Polonium (210Po) is the major contributor (with approximately 90%) to the radiation dose from radionuclides contained in the human diet, and it is mostly associated with seafood. This study presents 210Po activity concentrations in the tissues of 16 fish species from the Aegean Sea and Sea of Marmara. Among all species investigated, the highest 210Po activity concentration was 4450 ± 33 Bq kg−1 dry weight (dw) in the digestive tract of anchovy (Engraulis encrasicolus), and the lowest 210Po activity concentration was 1.3 ± 0.6 Bq kg−1 (dw) in the muscle tissue of the thornback ray (Raja clavata). Significant differences in 210Po concentrations were consistently found among the tissues of fish (P < 0.05). In general, the prominent accumulation of 210Po was observed in the digestive tract and liver while the muscle tissue generally displayed the lower concentrations. Polonium concentrations in the internal organs, such as muscle and liver, were related to the feeding ecology of fish and thus are a consequence of 210Po transfer in the food chain rather than 210Po uptake from water. The average 210Po concentration in fish filet was 54.1 Bq kg−1 dw and to attain the recommended limit for the annual committed effective dose (1 mSv year−1) would require the consumption of 1024 kg of mixed fish filet in 1 year, which is unlikely to happen. The highest 210Po activity concentration in the edible part of fish (filet) was determined in the anchovy (E. encrasicolus) but to reach the 1 mSv year−1 limit would require still the consumption of 7.1 kg year−1 of anchovy filet. Similar size specimens of wild and farmed fish, Dicentrarchus labrax and Sparus aurata, were analyzed to assess the differences in 210Po concentrations. Polonium concentrations in the wild fish were several-fold higher than in farmed specimens, these ones fed with fish feed with 210Po content lower than natural food in the sea. Therefore, the current trend of increasing the consumption of seafood from aquaculture seems to be reducing the radiation exposure to 210Po in the human diet that is considered beneficial to public health. [ABSTRACT FROM AUTHOR]

Existing equations to estimate ventilation (VE) may not represent the Chinese population. The objective is to develop regression equations to predict the basal metabolic rate (BMR) for ventilation estimation. 80 participants underwent the incremental tests on a bicycle ergometer, wearing a fitted facial mask with an airflow sensor connected to the cardiopulmonary gas analyzer, where the energy expenditure, metabolic factors and VE were monitored simultaneously. Linear regression models were established between BMR and body weight, which were used to estimate energy expenditure and VE. Extrapolation of the regression model was evaluated by the five-fold cross-validation. And we also assessed the inhaled load of air pollutants in subgroups at the same exposure levels. Regression models for males and females were BMR (kJ/d) = 107.58 × weight (kg)-172.61 and BMR (kJ/d) = 105.61 × weight (kg)-26.94, respectively. The model showed good fitness between the measured and predicted VE. Differences between the measured and predicted VE of this model are smaller than that of other models. There were significant differences in inhaled load participants in the same exposure concentrations. The regression model showed that weight and BMR are highly correlated and can be used to estimate individual VE. [ABSTRACT FROM AUTHOR]

Heavy-ion radiotherapy is currently recognized as the most advanced particle therapy method and is being vigorously promoted and applied worldwide. This method can rapidly generate radiation and induce radioactivity during treatment. However, the induced radioactivity, which is the primary source of exposure for medical staff, does not disappear following therapeutic application in the treatment room. In this study, we investigated the characteristics, dose rate distribution, and impact of this induced radioactivity on medical staff in the treatment room (uniform scanning mode) at Gansu Wuwei Tumor Hospital using experimental measurement and Monte Carlo simulation. We found that the exposure dose experienced by medical staff is predominantly related to the irradiated patients for single irradiation and the irradiated beam delivery system for long-term irradiation. The half-lives of the main radionuclides ranged from a few minutes to tens of minutes for single irradiation and from tens of days to hundreds of days for long-term irradiation. The primary radionuclide contributors are 15O, 11C, 176Ta, and 177W. We also estimated the personal dose experienced by the medical staff in the treatment room in relation to their working patterns. The results showed that the maximum annual exposure dose of medical staff in the horizontal treatment direction under the current model was 0.728 mSv. We hypothesized that an appropriate increase in the patient's treatment could reduce the annual exposure dose of medical staff to 0.650 mSv without changing the total treatment time per day. Finally, some suggestions were made to reduce the exposure of medical staff to unwanted radiation.

The Japanese Journal of Health Physics has shown many articles related to the accident at the TEPCO's Fukushima Daiichi NPP in March 2011. In these, 23 articles on dosimetry and dose assessment have been published up to March 2022. The dosimetry data and dose assessment methods reported in these articles are valuable knowledge in considering future radiation monitoring methods at accidents. [ABSTRACT FROM AUTHOR]

Heavy-ion radiotherapy is currently recognized as the most advanced particle therapy method and is being vigorously promoted and applied worldwide. This method can rapidly generate radiation and induce radioactivity during treatment. However, the induced radioactivity, which is the primary source of exposure for medical staff, does not disappear following therapeutic application in the treatment room. In this study, we investigated the characteristics, dose rate distribution, and impact of this induced radioactivity on medical staff in the treatment room (uniform scanning mode) at Gansu Wuwei Tumor Hospital using experimental measurement and Monte Carlo simulation. We found that the exposure dose experienced by medical staff is predominantly related to the irradiated patients for single irradiation and the irradiated beam delivery system for long-term irradiation. The half-lives of the main radionuclides ranged from a few minutes to tens of minutes for single irradiation and from tens of days to hundreds of days for long-term irradiation. The primary radionuclide contributors are 15O, 11C, 176Ta, and 177W. We also estimated the personal dose experienced by the medical staff in the treatment room in relation to their working patterns. The results showed that the maximum annual exposure dose of medical staff in the horizontal treatment direction under the current model was 0.728 mSv. We hypothesized that an appropriate increase in the patient's treatment could reduce the annual exposure dose of medical staff to 0.650 mSv without changing the total treatment time per day. Finally, some suggestions were made to reduce the exposure of medical staff to unwanted radiation. [ABSTRACT FROM AUTHOR]

Rural and isolated communities traditionally lack adequate water treatment and distribution systems, and water quality assessment often does not include radioactivity measurement. Here we present, for the first time, the results of Rn measurements and the evaluation of the associated dose in groundwaters of rural communities in a semiarid area in Paraiba State, Brazil. Water samples were analysed using a low-level liquid scintillation spectrometer (LSS). Radon concentrations were higher than EPA and WHO recommended levels in water for most of the wells (range of 5.5–1107.0 Bq/L, average 252.8 Bq/L). Higher Rn concentration was measured in deeper wells and located in area rich in granite and diorite rocks. The annual effective doses varied between 0.021 and 4.317 mSv/y for infants, 0.016–3.182 mSv/y for children, and 0.015–3.022 mSv/y for adults, exceeding, in some cases, the 1 mSv/y reference level recommended by the WHO and UNSCEAR for the public. Thus, water consumption from half of the wells should be avoided unless adequate treatment is provided. Results highlight the need to perform actions to supply water with appropriate quality to the local population. [ABSTRACT FROM AUTHOR]

In Taiwan, the Nuclear Safety Commission (NUSC) is the competent authority responsible for ensuring the safety of ionizing radiation operations. In recent years, the NUSC has introduced the concepts of ALARA and dose constraints (as recommended by the International Commission on Radiological Protection), to control the radiation safety of various radiation sources, and to review the protective control measures. Consideration of these concepts can help ensure that industry operators optimize radiation protection in planned exposure situations. This study investigated the occupational exposure of facility operators using nonmedical planned exposure radiation sources in Taiwan. The NUSC provided a sampling roster, and survey respondents were randomly selected. An on-site radiation safety survey was conducted using a calibrated handheld radiation survey meter to measure the doses that radiation workers were exposed to during normal operations. In addition, the dose constraints of multiple radiation practices were evaluated through the statistical analysis of dose data. From 2020 to 2023, on-site radiation dose surveys were conducted on 1614 radiation sources. Additionally, the average occupational exposure doses of workers in relation to multiple nonmedical radiation operations were evaluated, and recommended dose constraints for these operations were proposed. • A total of 1614 on-site radiation dose surveys is performed. • Dose constraint values estimated by the annual average dose+ 3σ standard deviation. • For public, dose constraint value is regarded as 30% of the occupational value. • Dose constraint value for permitted photographic inspection X-ray is 8 mSv/y. • Dose constraint value for registered mobile X-ray is 5 mSv/y. [ABSTRACT FROM AUTHOR]

This paper presents a versatile and cost-effective system for the monitoring of X-ray exposure during dental cone beam computed tomography procedures based on silicon PIN photodiode detectors. The system, developed and implemented at the University of Pisa's School of Engineering, underwent characterization under a range of operational conditions focusing on full field-of-view 3D protocols used in adult patient examinations. This study was facilitated by the Azienda Ospedaliero Universitaria Pisana, which provided access to a Planmeca ProMax 3D Classic scanner for the research. During the investigation, photodiodes were placed both on the surface and inside an Alderson RANDO phantom head to assess the dose delivered to regions near radiation-sensitive areas such as the salivary glands, thyroid, eye lens, and laryngopharynx. The evaluation process spanned a spectrum of tube voltages, ranging from 60 to 90 kVp, and tube currents, extending up to 16 mA, to ensure a broad and thorough analysis. Furthermore, to reinforce the effectiveness of the silicon photodiodes' measurement capabilities, calibrated GR-200 A-type thermoluminescent dosimeters were positioned within the phantom head inserts to serve as a reference point. Complementing this setup, PCXMC Rotation 2.0 simulations were conducted to further the efficacy of the monitoring system, particularly tailored to the specific dental CBCT protocols being investigated. In conclusion, while the research revealed a generally consistent correlation across PCXMC simulations, photodiode readings, and thermoluminescent dosimeter measurements, it is important to note that a direct comparison was not exactly possible due to limitations in the size and positioning of the systems. Variations up to 20–35% were observed, primarily due to the different positioning of the dosimeters and the unique physical and operational traits of the different measurement methods employed. Nevertheless, the development of an affordable, easily deployable, and scalable dosimetry monitoring system may provide a substantial contribution to enhancing patient safety in dental radiology and aid in the optimization of diagnostic X-ray protocols. • Dose monitoring in dental CBCT using cost-effective silicon PIN photodiodes. • Photodiodes' calibration against reference detectors for organ dose assessment in 3D dental imaging. • Integration of PCXMC simulations for radiation exposure assessment during dental imaging protocols. • Comparison of TLD measurements and photodiode data to identify absorbed dose trends in dental CBCT applications. [ABSTRACT FROM AUTHOR]

The activity concentrations of Po-210 were determined in seawater (<0.45 μm), suspended particulate matter (0.45–20 μm), fractionated plankton (20–50 μm, 50–200 μm, >200 μm) and tissues from four fish species, namely European seabass (Dicentrarchus labrax), Golden grey mullet (Chelon auratus), Gilt-head bream (Sparus aurata) and Common pandora (Pagellus erythrinus), collected in the Gulf of Trieste (northern Adriatic Sea). The activity concentration of Po-210 in seawater varied from 0.4 to 2.2 mBq/L in the dissolved phase (<0.45 μm) and from 0.4 to 0.8 Bq/L in suspended particulate matter (0.45–20 μm). Plankton fractionation showed the levels of 62–395 Bq/kg Po-210 in the >200 μm mesoplankton fraction, 65–459 Bq/kg in 50–200 μm and 52–537 Bq/kg in 20–50 μm microplankton fractions. No significant differences were found between fractions. The Po-210 distribution trend in fish tissues was in order: liver > stomach with intestine > kidney > spleen > gonads > gills > muscle. Bioaccumulation factors were determined for fish tissues indicating that the amount of Po-210 mostly depends on fish feeding habits. Hence, the main pathway entry of Po-210 is through ingested food. The highest estimated average total annual effective ingestion doses of Po-210 are obtained via the consumption of Common Pandora (7.1 μSv/year to 16.5 μSv/year) while the lowest doses are due to the consumption of European seabass (0.32 μSv/year to 0.76 μSv/year). Comparison with levels reported for other Mediterranean and Atlantic areas showed that only activitiy concentrations of Po-210 in fish appear significantly different, most likely because different fish species were analysed. The human dose exposure via fish consumption in the area is rather low. • Po-210 in seawater, suspended particles, plankton and fish tissues was determined. • Bioconcentration factors in plankton were determined. • Bioacumulation factors in fish tissues were determined. • The estimated average total annual effective doses were calculated. • Massic activitiy in fish is low and does not represent risk for human consumption. [ABSTRACT FROM AUTHOR]

In southern African countries most of the population uses groundwater collected in dug wells for domestic consumption instead of water from public distribution systems. To investigate the impact of natural and human factors on urban groundwater quality, 276 samples were collected in the Lubango region (Angola) in water distribution systems and dug wells ranging from a few meters to almost one hundred meters in depth. Radon concentrations (RC) were determined by liquid scintillation counting according to ISO 13164–4:2015. Geology is the main source of the variability of RC, with median values higher than 100 Bq/L in granitoid units and lower values in mafic and sedimentary units (ranging from 5 to 38 Bq/L). On average, RC was higher in dug wells compared to public water distribution systems. The annual effective dose due to ingestion of radon in water is, on average, ten times lower in the later compared to dug wells. Therefore, from a public exposure perspective, water distribution systems are preferred as means for water distribution. A severe multi-year meteorological drought over the past decade affecting 76–94 % of the population in southern Angola has been linked with climate change. Consequently, a regional lowering of the water table was observed, as well as a reduction in the productivity of shallower wells, leading to a search for water at greater depths. This work demonstrates an increase in median RC from 66 Bq/L in wells shallower than 30 m to values over 100 Bq/L with increasing depth of water extraction and for the same geological unit. The highest RC observed were also observed at the deepest wells. The dose ingested is proportional to RC, being also higher at deeper water extraction depths. The increase in public radiation exposure from radon ingestion due to water extraction at greater depths is attributed to the underlying issue of climate change. Monitoring water quality in terms of radionuclide concentration is advised to ensure the exposure to ionizing radiation remains at acceptable levels in the future. • New data about exposure to ionizing radiation from natural sources. • Geology and well depth influence radon concentration. • The ingested dose from radon in water distribution systems is lower than dug wells. • The ingested dose from radon is lower than inhaled dose. • Climate change-driven deep-water extraction increases ingested doses from radon. [ABSTRACT FROM AUTHOR]

During nuclear facility decommissioning, workers are continuously exposed to high-level radiation. Hence, adequate path planning is critical to protect workers from unnecessary radiation exposure. This work discusses recent development in radioactive path planning and the algorithms recommended for the task. Specifically, we review the conventional methods for nuclear decommissioning path planning, analyze the techniques utilized in developing algorithms, and enumerate the decision factors that should be considered to optimize path planning algorithms. As a major contribution, we present the quantitative performance comparison of different algorithms utilized in solving path planning problems in nuclear decommissioning and highlight their merits and drawbacks. Also, we discuss techniques and critical consideration necessary for efficient application of robots and robotic path planning algorithms in nuclear facility decommissioning. Moreover, we analyze the influence of obstacles and the environmental/radioactive source dynamics on algorithms' efficiency. Finally, we recommend future research focus and highlight critical improvements required for the existing approaches towards a safer and cost-effective nuclear-decommissioning project.

The safe evacuation of residents near a nuclear power plant during a nuclear accident is vital for emergency response planning. To tackle this challenge, considering the dynamic dispersion of radioactive materials in the atmosphere and its impact on evacuation routes under different meteorological conditions is crucial. This paper develops a dynamic dose-based emergency evacuation model (DDEEM), which is an efficient and optimized nuclear accident evacuation model based on dynamic radiological dose calculation, utilizing an improved A* algorithm to determine optimal evacuation routes. The DDEEM takes into account the influence of radiological plume dispersion and path selection on evacuation effectiveness. This study employs the DDEEM to assess radiological consequences and evacuation strategies for students residing 5 km from a Chinese nuclear power plant. Under various meteorological conditions, including the three typical meteorological conditions, random ordered and random unordered meteorological sequences, optimal routes obtained through the DDEEM effectively reduce radiological dose exposure and mitigate radiation hazards. The results indicate that all evacuation paths generated by the DDEEM have a maximum dose of less than 1 mSv. Through simulations, the model’s effectiveness and reliability in dynamic radiological environments in terms of radiological consequences and evacuation analysis is verified. The research provides valuable insights and a practical tool for nuclear power plant emergency decision-making, enhancing emergency management capabilities during nuclear accidents. The DDEEM offers crucial technical support and a solid foundation for developing effective emergency response strategies.

A low-enriched-uranium (LEU)–fueled space reactor could avoid the security and proliferation concerns inherent with highly enriched uranium (HEU)–fueled space nuclear reactors. Recent LEU-fueled space reactor designs include a moderator to reduce the size and mass of the reactor core. This paper considers shadow shield options for an unmoderated HEU-fueled space reactor and a moderated LEU-fueled space reactor. Both reactors are kilowatt-class reactors, producing 15 kW(thermal) of thermal power over a 5-year operational lifetime. Based on the shielding required to meet established dose limits [a neutron fluence of less than 1014 n/cm2 (1 MeV equivalent in silicon) and a gamma-ray dose of less then 1 Mrad in silicon], the moderated LEU-fueled space reactor will require a thicker shadow shield than the unmoderated HEU-fueled space reactor. The thinner reflector of the moderated LEU-fueled reactor results in more neutrons reaching the shadow shield at higher energies compared to the unmoderated HEU-fueled reactor. The presence of a significant reflector in most space reactor designs means that the core spectrum is relatively unimportant in terms of shadow shield design, as the reflector thickness has a much stronger impact on the neutrons and gamma rays reaching the shadow shield. Based on the results presented in this paper, the mass optimization of moderated LEU-fueled space nuclear reactors should always consider the coupled effects of the core, the reflector, and the shielding. [ABSTRACT FROM AUTHOR]

For evaluating the radiological safety of dismantled concrete, the process of disposal and recycling of the radioactive concrete generated during the dismantling of Kori Unit 1 is analyzed. Four scenarios are derived based on the analysis of the concrete recycling and disposal process, and the potential exposure to the workers and public during this process are calculated. VISIPLAN and RESRAD code are used for evaluating the dosages received by the workers and public in the following four scenarios: concrete inspection, transport of concrete by the truck driver, driving on a recycled concrete road, and public living near the landfilled concrete waste. Two worker exposure scenarios in the processing of concrete and two public exposure scenarios in recycling and disposal are considered; in all the scenarios, the exposure dose does not exceed the annual dose limit for each representative.

The radiological safety of the spent resin treatment facility with a14C treatment capacity of 1 ton/day was evaluated in terms of the external and internal exposure of worker according to operation scenario. In terms of external dose, the annual dose for close work for 1 h/day at a distance of more than 1 m (19.8 mSv) satisfied the annual dose limit. For 8 h of close work per day, the annual dose exceeded the dose limit. For remote work of 2000 h/year, the annual dose was 14.4 mSv. Lead shielding was considered to reduce exposure dose, and the highest annual dose during close work for 1 h/day corresponded to 6.75 mSv. For close work of 2000 h/year and lead thickness exceeding 1.5 cm, the highest value of annual dose was derived as 13.2 mSv. In terms of internal exposure, the initial year dose was estimated to be 1.14E+03 mSv when conservatively 100% of the nuclides were assumed to leak. The allowable outflow rate was derived as 7.77E-02% and 2.00E-01% for the average limit of 20 mSv and the maximum limit of 50 mSv, respectively, where the annual replacement of the worker was required for 50 mSv.

With the rapid development of nuclear power, the radiation impacts on edible marine organisms, and the potential radiation risks to humans have become of considerable concern to public health. In this study, the activities of 210Po and 210Pb as well as those of other radionuclides in fishes (Mugil cephalus, Konosirus punctatus, Largehead hairtail, and Larimichthys polyactis), crustaceans (Mantis shrimp, Parapenaeopsis hardwickii, and Portunus trituberculatus), bivalves (Crassostrea gigas, Sinonovacula conzcta), and macroalgae (Gracilaria, Porphyra) collected in the coastal area adjacent to the Fuqing and Ningde nuclear power plants (NPPs) were determined. The activity range of 210Po and 210Pb was 0.60–48.09 and 0.07–2.76 Bq/kg freshweight, respectively, with 210Po/210Pb activity ratios of 1.1–189.7. The ranking of 210Po activity levels in marine organisms was bivalve mollusks > crustaceans > fishes > macroalgae. The calculated bioconcentration factors of 210Po and 210Pb were 636–44,944 and 3–1,226 L/kg, respectively. These values provide a new supplement to the IAEA reference database. The radiation dose rates for these marine organisms ranged from 0.037 to 1.531 μSv/h, which was much lower than the ERICA ecosystem screening benchmark of 10 μGy/h. The calculated committed effective dose received by humans from ingestion of these marine organisms was 0.06–2.99 mSv. Overall, 210Po was the dominant radiation dose contributor in marine organisms and humans, whereas the dose contributions from the artificial nuclides 90Sr and 137Cs were negligible.

This paper does not necessarily reflect the views of the International Commission on Radiological Protection. Several radiation monitoring research projects are underway on dose assessment, biological analysis, and risk communication under an agreement with Namie Town. Indoor radon and thoron progeny concentrations have been measured using passive-type monitors to estimate internal doses due to inhalation. In addition, airborne radiocaesium concentrations at five points in Namie Town have been analysed using a high-purity germanium detector to estimate internal doses for comparison with radon. External radiation doses from natural and artificial radionuclides have also been estimated using an in-situ gamma-ray spectrometer. Other support activities are mentioned briefly in this article, [ABSTRACT FROM AUTHOR]

The present investigation deals with gamma radiation survey and analysis of uranium in groundwater samples collected from the Kanniyakumari district. It reveals that gamma dose rate varies from 58 to 3880 nSv/h (mean 276 nSv/h) and uranium concentration varies from ≤ 0.2 to 10 µg/L (median 0.4 µg/L) in the pre-monsoon and ≤ 0.2 to 14.9 µg/L (median 0.2 µg/L) in the post-monsoon seasons. The present study shows that Manavalakurichi and Indranagar junctions have high background radiation due to the monazite placer deposits. The alkaline and reductive nature of groundwater minimizes the leaching of uranium from these monazite placer deposits. [ABSTRACT FROM AUTHOR]

[Display omitted] • The BEPU approach is utilized for dose assessment purposes. • An LBLOCA is considered as the accident scenario. • The HotSpot code is employed for performing best estimate calculations. • Wilks' statistical method is used to generate input data with a proper confidence level. • The calculated dose values did not lead to a loss of safety margin in the analyzed scenario. A key element in the process of accident analysis for the event of a severe nuclear emergency such as the large break loss of coolant accident (LBLOCA) is to properly quantify safety margins using reliable tools. Assessing the consequences of radioactive material release and the equivalant dose after the LBLOCA can provide clarity about the accident. Reliable safety analysis methods for nuclear power plants (NPPs) can be used to obtain relatively realistic outcomes considering the complex uncertainties of NPP events. In this study, an appropriate technique for sensitivity and uncertainty analysis is employed to develop a methodology for performing dose assessment within a postulated LBLOCA including uncertainties. Considering the approved reliability over the years and safety aspects, VVER reactor is among the most widely used nuclear reactors, which is selected as the case study in this article. The main problem that the study aims to solve is to illustrate whether the inordinate deviation of the input parameters from their reference values lead to violation of the allowed TEDE value by conducting uncertainty analysis. For performing calculations of total effective dose equivalent (TEDE), the environmental contamination with radioactive materials has been simulated using HotSpot code and the obtained results were compared with the solutions of JRODOS program. To obtain the most influential parameters on the obtained TEDE values in different distances from the NPP, an appropriate sensitivity analysis has been carried out, following which the Wilks' statistical method is used to generate 59 data samples with uncertainty propagation and 95 % confidence. The resulting uncertainty bands demonstrate that the maximum TEDE values of calculated data lie within about 7 to 15 mSv in the postulated LBLOCA scenario, which are below the threshold limit of 50 mSv recommended by International Atomic Energy Agency. [ABSTRACT FROM AUTHOR]

Based on the monitoring data of 137Cs and 90Sr in Tian Bay in 2005–2023, the impacts of the operation of Tianwan Nuclear Power Plant on the marine ecosystem were assessed. The 137Cs and 90Sr activity concentrations in the seawater and sediment varied within the background ranges. The radiation dose rates derived from 137Cs and 90Sr for the marine organisms ranged from 2.4 × 10−5 to 2.2 × 10−4 nGy/h, it was far below the most conservative screening dose rate (10 μGy/h). The committed effective dose for humans was 0.070–0.094 μSv, 1/1500th of the world's mean annual effective dose (0.12 mSv) from ingesting food containing uranium and thorium series nuclides. Radiation risk assessment showed no radiation risk for the long-term discharge of nuclear wastes in the future. Overall, the long-term normal operation of TNPPs has almost no radiation impact on the adjacent marine ecosystem. • 137Cs and 90Sr fluctuated within the background range of Tian Bay. • Dose rate from 137Cs and 90Sr to marine biota was far below the threshold (10 μGy/h). • No radiation effect on the marine ecosystem of Tian Bay from radionuclides • No radiation risk for long-term discharge of low-level radioactive waste to Tian Bay [ABSTRACT FROM AUTHOR]

Due to variation among radiographers' practice, and the importance of unifying practice during radiography for optimizing radiation level and image quality, the current manuscript aims to assess the radiation dose level and propose local diagnostic reference levels (LDRL) for posterior-anterior (PA) chest, antero-posterior (AP) abdomen, and pelvis examinations in two hospitals in Khartoum ('K') and one hospital in Wad-Medani ('M') cities, Sudan. Along with patient demographics like height and weight, the radiation exposure parameters including tube potential, current, and radiation duration were documented. This included 732 patients whose tests were conducted at one of three departments located in two different cities. The entrane surface air kerma (ESAK) was calculated using DosCal software and an Unfors -Xi-meter. The average ESAK for an X-ray of the chest was 0.18 mGy in M, 0.19 mGy in K (averaged over two hospitals in the K), for the abdomen it was 1.1 and 1.23 mGy, and for the pelvis it was 1.8 and 01.9 mGy respectively. The proposed DRL was achieved from the third quartile of radiation dosage of data, and it was 0.21, 1.7 and 1.9 mGy for the chest, abdomen and pelvis respectively. There was a wide variation in dosage levels among the three hospitals. The current proposed DRL was lower than most literature for the chest, abdomen and pelvis. More studies are recommended for other examinations such as skull and contrast media studies. • Radiation dose level for chest, abdomen and pelvis was assessed in major hospitals in Sudan. • Average dose for conventional X-ray of chest, abdomen and pelvis was 0.19, 1.2 and 1.9 mGy respectively. • Local diagnostic reference level was suggested for the above examinations. • The Suggested LDRL was lower than available literature. [ABSTRACT FROM AUTHOR]

The present paper proposes a novel method, based on Bayesian statistics, as a new approach in the field of thermoluminescence dosimetry for the assessment of personal doses in mixed beta-gamma radiation fields. The method can be utilized in situations when the classical way of dose calculation is insufficient or impossible. The proposed method uses a prior function which can be assigned to the unknown parameter and the likelihood function obtained from an experiment, which together can be transformed into the posterior probability distribution of the sought parameter. Finally, the distribution is converted to the value of the dose. The proposed method is supported by analytical and Monte Carlo calculations, which confirmed the results obtained through the Bayesian approach. [ABSTRACT FROM AUTHOR]

The Philippine Research Reactor-1 (PRR-1) fuel storage facility is a wet storage for irradiated nuclear fuel. The behavior of the facility in case of accidental loss of water is currently unknown. Safety analysis of a repository of fissile material involves criticality safety assessment and radiation dose estimation for normal and accident scenarios. To determine the radiological consequences of loss of water inventory in the fuel storage facility, we calculated the effective multiplication factor (keff) and gamma dose rate distribution in the system using Monte Carlo N-particle (MCNP) radiation transport code. Results show that keff will decrease from a maximum of 0.61424 ± 0.00013 when the water level is decreased from its fully moderated condition. In contrast, keff will increase to a maximum of 0.7468 ± 0.0002 when voids are introduced in the water. These results indicate that the system will remain subcritical (keff<1) and a runaway supercritical fission chain reaction cannot result from any moderating conditions. Furthermore, the dose assessment for the case of complete loss of water revealed a maximum dose rate of 5.52 ± 0.045 mSv/h and 288 ± 4.65 μSv/h at the tank surface and tank platform, respectively. These values are significantly above background radiation levels; however, the calculated spatial distribution is highly asymmetric and the dose rate falls off rapidly with increasing distance. These results suggest that a facility-level emergency response is sufficient to address the accident. Our findings can augment the existing facility emergency procedures, thereby contributing to the improvement of radiological safety. [ABSTRACT FROM AUTHOR]

The experiences of the Chernobyl and Fukushima nuclear accidents showed that dosimetry was the essential tool in the emergency situation for decision making processes, such as evacuation and application of protective measures. However, at the consequent post-accidental phases, it was crucial also for medical health surveillance and in further adaptation to changed conditions with regards to radiation protection of the affected populations. This review provides an analysis of the experiences related to the role of dosimetry (dose measurements, assessment and reconstruction) regarding health preventive measures in the post-accidental periods on the examples of the major past nuclear accidents such as Chernobyl and Fukushima. Recommendations derived from the review are called to improve individual dose assessment in case of a radiological accident/incident and should be considered in advance as guidelines to follow for having better information. They are given as conclusions.

Experience suggests that current nuclear accident response planning in European countries mostly has a technical focus, with less attention paid to social, psychological and ethical issues. Information provided tends to be directed towards decisions made by experts, rather than for the support of affected populations. The SHAMISEN (Nuclear Emergency Situations - Improvement of Medical And Health Surveillance) consortium, composed of close to 50 experts from 10 countries, performed a critical review of current recommendations and experiences regarding dose assessment and reconstruction, evacuation decisions, long-term health surveillance programmes and epidemiological studies. The review included case studies and lessons drawn from the living conditions and health status of populations affected by the Chernobyl and Fukushima accidents, taking an integrative approach to health and well-being. Based on this work, SHAMISEN developed a series of comprehensive recommendations aimed at improving the preparedness, response, long-term surveillance and living conditions of populations affected by past or future radiation accidents, in a manner responding to their needs, while minimising unnecessary anxiety.

This work reports comprehensive time-series datasets over the past 50 years for natural ( 210 Po) and anthropogenic ( 134 Cs and 137 Cs) radionuclides in three fish species (cod, herring and plaice) from Danish marine areas covering the North Sea, Kattegat, and Baltic Sea. Impact from the global fallout of atmospheric nuclear weapons testing, radioactive discharges from the European nuclear reprocessing plants and release from Chernobyl accident are clearly detected in the fish samples. While 210 Po concentrations in each fish species demonstrated comparable levels across the three regions without notable temporal trends, significantly higher median 210 Po concentration was observed in the lower trophic level fish, namely herring and plaice, compared to cod. In contrast, 137 Cs concentrations in all three species steadily decrease over time after the Chernobyl-attributed peaks in late 1980s in the entire study area, whereas 137 Cs always demonstrated higher concentrations in cod than herring and plaice. Our calculated concentration factors (CFs) for 137 Cs in this work indicate that the mean CFs for 137 Cs over the past 50 years are significantly different across the three species, following the order of cod < herring < plaice. Based on the time-series data, ecological half-lives (T eco ) of 137 Cs in fish from Danish marine areas were estimated to evaluate the long-term impact of anthropogenic radioactive contamination in different regions. Our results indicate no significant difference in T eco across different fish species, whereas the weighted mean T eco for fish in the Baltic Sea (29.3 ± 3.9 y) is significantly longer than those of the North Sea (9.8 ± 0.9 y) and Kattegat (11.7 ± 1.2 y), reflecting the strong 'memory effect' of the Baltic Sea due to its slow water renewal. However, the dose assessment demonstrates that the contribution of the natural radionuclide 210 Po to ingestion dose from fish consumption is 1-2 order of magnitude higher compared to that of 137 Cs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The heat flux system within the Precambrian basement complex in northwestern Nigeria has been poorly studied and little is known about the potential of the constituent petrologic units as regards geothermal resources. The earth crust gets heated up by a combination of processes, prominent among them is radioactive decay of 40K, 232Th and 238U radionuclides. Radioelement concentrations were measured within the rock units that dominate the basement complex namely quaternary sediments, carbonates, metasediments, younger granites, metavolcanics, older granites, migmatite and gneissic rock. Statistical parameters were estimated to deduce the radioactive absorbed dose of the various rock units. Quaternary sediments recorded the lowest mean dose while gneissic rock recorded the highest mean dose given as 112.09 nGy.h−1 and 264.54 nGy.h−1 respectively. One-way analysis of variance performed in this study showed distinct statistical significant variations of the radioelement concentrations in the dose assessment of the rock units. The contributing percentages of the radioelements for all the studied rock units were in the order 40K > 232Th > 238U. Two major classes of rock unit namely clastic rocks and plutonic rocks were assessed for their heat production capacity. The clastic rocks comprising quaternary sediments and carbonates presented mean heat production units given as 0.528 µWm−3 and 0.784 µWm−3 respectively while the plutonic rocks comprising granite and gneissic rock presented mean heat production units given as 1.404 µWm−3 and 1.982 µWm−3 respectively. Subsequently, heat generation unit estimations were extrapolated from the heat production values with gneissic rock showing the highest value given as 5.5660 HGU. These results which may assume theoretical pilot status towards geothermal resource investigation in northwestern Nigeria are in tandem with other similar studies performed around the globe.

This study presents the results of 226Ra content in 104 Bulgarian mineral waters as well as the investigated correlations between the physicochemical parameters, geological structure, and specific activity of 226Ra. The results show that the 226Ra activities range from

This research aimed to get information about the uranium and radium activity concentrations in surface and ground water in a semiarid region in Brazil. Mean (and range) activity of 0.46 (0.01–1.8), 0.015 (0.0004–0.066) and 0.32 (0.09–1.32) Bq L− 1 were found for 234U, 235U and 238U, respectively. Uranium radioisotopes account for the higher radioactivity in surface and groundwater, 226Ra was found only in few groundwater samples (0.09–0.61 Bq L− 1). 226Ra/238U (0.15–0.43) and 234U/238U (1.18–1.86) activity ratios are indicative of radioactive disequilibrium in groundwater. Expected effective doses from few water sources can be considered significant if untreated water is used for drinking. [ABSTRACT FROM AUTHOR]

The exposure to uranium (U) in the natural environment is primarily through ingestion (eating contaminated food and drinking water) and dermal (skin contact with U powders/wastes) pathways. This study focuses on the dose assessment for different age-groups using the USEPA model. A total of 156 drinking water samples were tested to know U level in the groundwater of the study region. Different age-groups were selected to determine the human health impact due to uranium exposure in the residing populations. To determine the relative importance of each input, a variance decomposition technique, i.e., Sobol sensitivity analysis, was used. Furthermore, different sample sizes were tested to obtain the optimal Sobol sensitivity indices. Three types of effects were evaluated: first-order effect (FOE), second-order effect (SOE) and total effect. The result of analysis revealed that 17% of the samples had U concentration above 30 µg l−1 of U, which is the recommended level by World Health Organization. The mean hazard index (HI) value for younger age-group was found to be less than 1, whereas the 95th percentile value of HI value exceeded for both age-groups. The mean annual effective dose of U for adults was found to be slightly higher than the recommended level of 0.1 m Sv year−1. This result signified that adults experienced relatively higher exposure dose than the children in this region. Sobol sensitivity analysis of FOE showed that the concentration of uranium (Cw) is the most sensitive input followed by intake rate (IR) and exposure frequency. Moreover, the value of SOE revealed that interaction effect of Cw − IR is the most sensitive input parameter for the assessment of oral health risk. On the other hand, dermal model showed Cw − F as the most sensitive interaction input. The larger value of SOE was also recorded for older age-group than for the younger group. [ABSTRACT FROM AUTHOR]

Drinking water may contain radioactive substances that could present a risk to human health (WHO, Guidelines for drinking-water quality: fourth edition incorporating the first addendum. World Health Organization, Geneva, 2017). Of particular significance for human radiation exposure from drinking water are the naturally occurring radionuclides that originate from the elements of the thorium and uranium decay series, such as 226Ra and 228Ra. These radionuclides can arise in water from natural processes in the ground or human activities involving naturally occurring radioactive materials (WHO, Management of radioactivity in drinking water. World Health Organization, Geneva, 2018). The measurement of radioactivity in drinking water allows the determination of population exposure to radiation by the habitual consumption of water. The aim of this study was to determine gross alpha and gross beta activities, and 226Ra and 228Ra activity concentrations in 28 drinking water samples from the Vojvodina region, in order to check compliance with recent Serbian and European regulations. Gross alpha and beta activity in drinking water samples were determined according to ASTM D7283-06 Standard test method for alpha- and beta-activity in water by liquid scintillation counting (ASTM D7283-06, Standard test method for alpha- and beta- activity in water by liquid scintillation counting. ASTM International West Conshohocken PA, https://www.astm.org, 2006), and measured by PerkinElmer liquid scintillation counter Quantulus 1220. The activity of 226Ra and 228Ra was determined by low-level gamma-spectrometry, and assuming the radioactive equilibrium between 226 and 228Ra and their progenies. For the analyzed radionuclides activity concentration in the water samples dose calculations were carried out. Gross alpha activity for all presented water samples exceeded the recommended guideline activity concentrations of 0.1 Bq L−1 (WHO, Guidelines for drinking-water quality, 2nd edn. World Health Organization, Geneva, 1993). The activity concentrations for 226Ra in 13 of investigated samples are higher than the legally established levels for radionuclide content in drinking water in Serbia and EU (Official Gazette, Rulebook on limits of radionuclides content in drinking water, foodstuffs, feeding stuffs, medicines, general use products, construction materials and other goods that are put on market, 2013; EC, Council Directive 2013/51/EURATOM, 2013). In 16 water samples concentration of 228Ra is higher than recommended. In 20 investigated samples, total dose GD from radionuclides in drinking water is higher than 0.1 mSv year−1 (EC, European Drinking Water Directive 98/83/EC of 3 November 1998 European Commission on the quality of water intended for human consumption. Off J L, 1998). The cancer risk caused by the intake of radium isotopes in drinking water during the lifetime was estimated, and the obtaining results are ranged in the acceptable cancer incidence (WHO, Guidelines for drinking-water quality, 4th edn. World Health Organization, Geneva, 2011; EPA, Cancer risk coefficients for environmental exposures to radionuclides. Environmental Protection Agency, Washington, DC, 1999). The presence of 226Ra and 228Ra are explained on the basis of geological and hydrogeological characteristics of the Vojvodina region. [ABSTRACT FROM AUTHOR]

• All patients' accumulated doses were satisfactory using tumor matching. • Bone matching may lead to hypofractionated carbon ion therapy failure. • Tumor matching enables a smaller required margin. • Daily CT alignment is necessary for patients with non-small cell lung cancer. This study aimed to assess dose distributions for stage I non-small cell lung cancer (NSCLC) with passive scattering carbon-ion radiotherapy (C-ion RT) using daily computed tomography (CT) images. We enrolled 10 patients with stage I NSCLC and acquired a total of 40 pre-fractional CT image series under the same settings as the planning CT images. These CT images were registered with planning CT images for dose evaluation using both bone matching (BM) and tumor matching (TM). Using deformable image registration, we generated accumulated doses. Moreover, the volumetric dose parameters were compared in terms of tumor coverage and lung exposure and statistical analyses were performed. Overall, 25% of 40 fractional dose distributions were unacceptable with BM, compared with 2.5% with TM (P < 0.001). Using BM, three patients' accumulated dose distributions were unacceptable; however, all were satisfactory with TM (P < 0.001). No differences were observed in water-equivalent path length (WEL). The required margins in patients with poor dose distribution were 5.9 and 4.4 mm for BM and TM, respectively. This study establishes that CT image-based TM is robust compared with conventional BM for both daily and accumulated dose distributions. The effects of changes in WEL seem to be limited. Hence, daily CT alignment is recommended for patients with stage I NSCLC receiving C-ion RT. [ABSTRACT FROM AUTHOR]