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In this study, the activity concentrations of gross alpha and gross beta in 125 drinking water samples (16 tap and 109 spring waters) collected from Ankara province were measured using a gas proportional α/β counter. The average (range) activity concentrations of gross alpha and gross beta were determined as 105 (20–495) mBqL−1 and 195 (70–850) mBqL−1, respectively. Average annual effective dose to adults caused by ingestion of water samples was estimated as 74.1 ± 43.2 µSv y−1. The average estimated cancer risk value depending on irradiations was calculated as 3.8 × 10−4 and 2.6 × 10−4 for the region using the nominal probability coefficients recommended by ICRP 60 and ICRP 103, respectively. Annual effective dose values in 10.4% of samples exceeded the limit values suggested by WHO for drinking waters in terms of beta activity and this was 0.8% for alpha activity. Moreover, contribution of 40K to the gross beta activity in drinking waters of the region was determined as 47%. [ABSTRACT FROM AUTHOR]

Aim: This study aims to estimate equivalent doses (EqDs) and life attributable risks (LARs) for pediatric patients who underwent chest–abdominal–pelvic (CAP) CT examinations in Madinah, Saudi Arabia. Methodology: This retrospective study collected data from 120 pediatric patients who underwent CAP CT examinations. The data were categorized by the age and gender of the pediatric patients. Then, the EqDs were computed using the NCICT (National Cancer Institute dosimetry system for computed tomography) program, and LARs were estimated from the equivalent dose (EqD) results using age- and gender-specific cancer risk models found in the Committee on the Biological Effects of Ionizing Radiation (BEIR) VII Phase 2 (2006). Results: The EqD range was 0.9 to 7.55 mSv for the prostate and colon (males and females), respectively. LARs for female breast and lung cancers were considered to have the highest values among the age groups. Nevertheless, LARs of the colon, liver, and leukemia cancers were higher for males than females. The LAR range of cancer incidence was 0.6 to 63.1 per 100,000 cases for prostate (aged 10–≤15 years) and breast (females aged 1≤–<5 years), respectively. The LAR range of cancer mortality was 0.1 to 41.9 per 100,000 cases for prostate (aged 10–≤15 years) and lung (females aged 1≤–<5 years). Conclusions: LARs of all cancer incidence and mortality from CAP CT examination were higher for pediatric females than males (with an average of 54%). This highlights the importance of considering pediatric patient gender and implementing optimization and protective measures in CAP CT examinations. LARs of breast and lung (for females) and colon (for males) cancers were found to have the highest values among the age groups. However, LARs of cancer incidence and mortality for colon, liver, and leukemia for males were higher than those for females. [ABSTRACT FROM AUTHOR]

This study involves continuous radon monitoring during the academic year 2023/2024. An Airthings Corentium Home radon detector placed in the basement laboratory of a faculty building in Kosovska Mitrovica (N 42.897°, E 20.867°) was used for continuous measurements. The average radon concentration was 303 Bq/m3, and a seasonal pattern during the measuring period was observed. For the first time, the results were grouped by week, excluding non-working days, to present a real case scenario with the aim of assessing the radon exposure of students, teachers, and employed persons. The inhalation dose from radon (1.54 mSv) was very high considering that exposure occurred in both semesters. Another aspect of continuous radon monitoring was to explore the relationship between indoor radon measurements and the occurrences of earthquakes in the Balkan region. Daily variations in radon (peaks and differences) were analyzed at the monitoring site by using both empirical laws and taking into account the earthquake data set provided by the Seismological Survey of Serbia. The analysis revealed that the events chosen to confirm a clear association between earthquake occurrence and enhanced radon activities in the air(as a precursor of seismic activities) did not meet the required criteria but most likely reflected external meteorological conditions. [ABSTRACT FROM AUTHOR]

Positron emission tomography (PET) scans are vital in diagnosing cancer and neurological disorders but raise concerns due to exposure to ionising radiation. This research is focussed on the development of an intelligent regression model to investigate the effective radiation dose received by a patient during the whole-body PET scan. Our newly developed intelligent model refers to the application of artificial intelligence (AI) and machine learning (ML) techniques. Since underfitting and overfitting are basic issues of any ML model, data fitting methodology for developing intelligent regression is taken care of by implementing the least absolute shrinkage and selection operator (Lasso) and ridge regression. In order to have the comparative performance of our model, we have also applied support vector and decision tree-based ML techniques as regressors to predict radiation doses in whole-body PET scans, keeping patient safety in mind. By incorporating patient-specific data and imaging parameters, these models aim to accurately estimate radiation doses, thereby optimising imaging protocols and reducing unnecessary exposure risks. The study uses PET / CT data from 2009 to 2012. The linearly-independent covariates applied in this model are age, weight, height, residence time and injected activity and the dependence variable is taken as the effective dose. Model performance is evaluated using root mean square error (RMSE). A systematic exploratory data analysis has been carried out to investigate data cleaning, missing information, scaling and normalisation. The top five organs such as the brain, stomach, kidney, adrenal and spleen are focussed to produce the traditional descriptive statistics of data summary. Least absolute shrinkage and selection operator (lasso) regression exhibit stable RMSE values for organ equivalent doses across genders, while substantial RMSE variations exist among different models and organs, suggesting sensitivity to specific organs and patient gender. Accurate dose estimation is pivotal for risk assessment and protocol optimisation. This study evidenced the need to improve radiation dosimetry for specific organs aiming at patient care and radiology practices by considering individualised factors in dose estimation methodologies to refine PET scan dose estimation methods. [ABSTRACT FROM AUTHOR]

Background/Objectives: Calculating the radiation dose from CT in 18F-PET/CT examinations poses a significant challenge. The objective of this study is to develop a deep learning-based automated program that standardizes the measurement of radiation doses. Methods: The torso CT was segmented into six distinct regions using TotalSegmentator. An automated program was employed to extract the necessary information and calculate the effective dose (ED) of PET/CT. The accuracy of our automated program was verified by comparing the EDs calculated by the program with those determined by a nuclear medicine physician (n = 30). Additionally, we compared the EDs obtained from an older PET/CT scanner with those from a newer PET/CT scanner (n = 42). Results: The CT ED calculated by the automated program was not significantly different from that calculated by the nuclear medicine physician (3.67 ± 0.61 mSv and 3.62 ± 0.60 mSv, respectively, p = 0.7623). Similarly, the total ED showed no significant difference between the two calculation methods (8.10 ± 1.40 mSv and 8.05 ± 1.39 mSv, respectively, p = 0.8957). A very strong correlation was observed in both the CT ED and total ED between the two measurements (r2 = 0.9981 and 0.9996, respectively). The automated program showed excellent repeatability and reproducibility. When comparing the older and newer PET/CT scanners, the PET ED was significantly lower in the newer scanner than in the older scanner (4.39 ± 0.91 mSv and 6.00 ± 1.17 mSv, respectively, p < 0.0001). Consequently, the total ED was significantly lower in the newer scanner than in the older scanner (8.22 ± 1.53 mSv and 9.65 ± 1.34 mSv, respectively, p < 0.0001). Conclusions: We successfully developed an automated program for calculating the ED of torso 18F-PET/CT. By integrating a deep learning model, the program effectively eliminated inter-operator variability. [ABSTRACT FROM AUTHOR]

Study Design: Experimental single-centre study of X-ray absorption using a phantom skull. Objective: This experimental study aimed to compare the radiation doses of different 3D imaging devices used in maxillofacial surgery, including one Multidetector CT (MDCT), two Conebeam CT (CBCT) and four intraoperative 3D C-arms. Methods: Thermoluminescent dosimeters (TLD) were used to determine the absorbed radiation in an Alderson-Rando phantom skull. The phantom skull was positioned in the before mentioned seven devices and a defined 3D facial skull image was acquired. Subsequently, the TLD'S were read out and the effective doses (ED) and the organ doses (OD) were calculated and compared. Results: OD varied significantly between tissues as well as between the 3D X-ray devices. The OD of the 3D C-arms were significantly lower than those of all other devices. The OD of the CT, especially in the standard setting, was the highest. Only by special adjustments of the scan protocol regarding CMF requirements for traumatology, the MDCT could achieve almost equivalent doses as the two tested CBCT-scanners. The calculated effective doses were also lowest for the 3D C-arm devices (11.2 to 129.9 μSv). The ED of the MDCT were significant higher (284.52–844.97 μSv) than in all other devices. The ED of the CBCTs (173.7–184.9) were lower than for MDCT but still higher than those of the 3D C-arms. Conclusions: Intraoperative imaging using 3D C-arm devices is an effective method to verify reduction results in maxillofacial surgery intraoperatively with significantly lower ED than postoperatively CBCT and MDCT imaging. [ABSTRACT FROM AUTHOR]

This study evaluated the occupational exposure of radiopharmacists, nurses, radiological technologists, and radiological technologist assistants involved in 99mTc-MDP bone scintigraphy procedures. Actual occupational effective doses for individual staff needed ascertaining. An environmental radiation exposure audit revealed all nuclear medicine areas were compliant with ICRP and IAEA guidelines. To ascertain individual doses, they were recorded by OSL badges. The highest exposure was to the radiopharmacists, Hp(0.07) 2.19 µSv during radiolabeling. The nurse administering 99mTc-MDP recorded a dose of 0.27 µSv at Hp(0.07), 26.01% of the total occupational effective dose. The radiological technologist and assistant receive 73.05% of the total effective dose. However, the highest effective dose was received by the technologist assistant positioning patients for SPECT/CT scans, with an effective dose of 32.03 µSv. Single and double dosimetry effective dose estimate algorithms were evaluated, resulting in the double dosimetry being more accurate. The Padovani et al. algorithm was found to most closely align with 99mTc-MDP actual effective dose values (p > 0.05), thereby validating the measurement methods used in this study. The research offers benchmark environmental exposure and effective doses applicable in audits and the continuous effort to enhance radiation safety for personnel during 99mTc-MDP bone scintigraphy. [ABSTRACT FROM AUTHOR]

This study proposes a model for phytoremediation coupling transport in soil and dynamic model using sunflower plants and 134Cs radionuclide. The model was validated by comparison with experimental measurements. The error value obtained, ranging from 0.00045–0.5268, is quite small, and the overall simulation data has approached the experiment. Factors influencing radionuclide concentration in different blocks include saturation point values, absorption rates of plant parts, soil dispersion coefficient, and velocity. The model is used to predict doses from ingesting sunflower seeds and estimates the soil-to-plant transfer factor. This new model is recommended for accurate assessment of environmental risks associated with radionuclides and for efficient decontamination. [ABSTRACT FROM AUTHOR]

Due to the consequences of nuclear and/or radiological accidents in the past (Chernobyl, Fukushima, etc.), and potential future events of that kind, the constant monitoring of environmental radioactivity is important. There are different pathways of the transfer of radionuclides from environment to humans (ingestion, inhalation and external). Food ingestion greatly contributes to the total effective dose; hence, it is of great importance to investigate exposure to radionuclides through food. This paper presents the results of a long-term investigation of 137Cs activity concentration in apples in northwestern Croatia for the period 1968–2023. The highest 137Cs activity concentration in apples was measured in 1986, decreasing exponentially ever since. The Fukushima-Daiichi accident in 2011 did not cause a significant increase in 137Cs activity concentration, although the presence of the consequent fallout was detected via the appearance of 134Cs in some parts of the environment. The observed residence time for 137Cs in apples was estimated to be 4.5 and 3.9 years for the pre-Chernobyl and post-Chernobyl periods, respectively. The correlation between 137Cs in fallout and apples is very good, the correlation coefficients being 0.99, which indicates that fallout is the main source of contamination. The estimated effective dose received by adult members of the Croatian public due to intake of radiocaesium from apples over the overall observed period is 6.4 µSv. Therefore, the consumption of apples was not a critical pathway for the transfer of radiocaesium to humans. [ABSTRACT FROM AUTHOR]

The Moon lacks a global magnetic field and atmosphere, leaving its surface been directly exposed to high‐energy cosmic radiation. Sporadic Solar Particle Events are sources of a significant radiation exposure, potentially posing serious threats to the health of astronauts exploring the Moon. In this paper, we use the Radiation Environment and Dose at the Moon (REDMoon) model based on GEometry And Tracking (GEANT4) Monte‐Carlo method to calculate the body effective dose induced by 262 large historical SEP events on the Moon under different shielding depths which can result from the lunar regolith shielding and/or additional aluminum shielding. We calculate and compare the contributions of different particles from or produced by SEPs to the total body effective dose. Additionally, we develop empirical functions to rapidly assess SEP‐induced effective dose on the Moon under different shielding scenarios. Plain Language Summary: The Moon lacks the protection of a magnetic field and atmosphere, allowing high‐energy cosmic radiation to directly reach the lunar surface, impacting the health of future astronauts on the Moon. Occasionally, solar eruptions can accelerate particles to very high energies and significantly enhance the radiation risks for lunar explorers. Since SEP exposure could potentially lead to in‐flight consequences, it is crucial to mitigate these risks. In this work, we use proton spectra of SEP events from two databases based on measurements and theoretical extrapolation. Using a newly developed lunar radiation environment model, we calculated the effective dose caused by different events under various aluminum shielding conditions on and beneath the lunar surface. Additionally, for different conditions, we developed a method to quickly predict the effective dose based on incoming SEP particle flux. Key Points: We calculate the body effective dose induced by Solar Energetic Particle (SEP) Events on the Moon with different shielding thicknessWe discuss the contribution to the effective dose from SEP protons with different incoming energies under different shielding conditionsWe develop empirical functions for predicting the SEP‐induced body effective dose on the Moon directly from the SEP flux at a given energy [ABSTRACT FROM AUTHOR]

This study aims to estimate organ dose and cancer risks, establish region-specific diagnostic reference levels (DRLs), and determine achievable doses (ADs) for common CT procedures in adults in the northwest of Iran. Effective and organ doses were estimated using VirtualDoseCT software in a sample of 480 adult patients who underwent head, sinus, chest, and abdomen-pelvis (AP) CT scans. The guidelines provided by the BEIR VII report were utilized to estimate cancer risks. Effective and organ doses for specific procedures were determined, with the highest mean organ dose being observed in the brain during head CT examinations, with a value of 54.02 mGy. It was observed that the lungs in chest examinations and the colon in AP examinations had the highest risk of cancer, with rates of 30.72 and 21.37 per 100,000 persons, respectively. Higher cancer risk values were generally exhibited by females compared to males. The DRLs for common CT examinations were established as follows: Head CT (CTDIvol 41 mGy, DLP 760 mGy cm), Sinus CT (CTDIvol 16 mGy, DLP 261 mGy cm), Chest CT (CTDIvol 8 mGy, DLP 287 mGy cm), and AP CT (CTDIvol 9 mGy, DLP 508 mGy cm). Significant variations in dose distribution among facilities were identified, indicating the need for optimization. The study highlights the importance of minimizing radiation exposure to critical organs and promoting patient safety in CT examinations. The establishment of region-specific DRLs and ADs can help optimize radiation doses and reduce cancer risks for patients. [ABSTRACT FROM AUTHOR]

Objectives: This study examines individual organ doses and the impact of ionizing radiation sources on effective radiation doses. Methods: In the research, the ICRP-defined adult standing phantom was used as the phantom material in the Visual Monte Carlo Dose Calculation Program (VMC). Subsequently, the incurred doses were calculated by defining different doses, distances, and durations for the 99mTc radioactive source. Results: Exposure times were set at 5 minutes and 20 minutes in comparison. The results indicated that for 5 minutes and 20 minutes at 360 cm, doses remained below the ICRP recommended annual dose limit of 5.7 µSv/h for occupational exposure. Conclusion: Organ absorbed and effective doses varied with exposure time and source-phantom distance. To optimize radiation exposure, people working in radiation fields must make an increased effort to reduce radiation doses following the ALARA principles. [ABSTRACT FROM AUTHOR]

Background/Objectives: Calculating the radiation dose from CT in 18F-PET/CT examinations poses a significant challenge. The objective of this study is to develop a deep learning-based automated program that standardizes the measurement of radiation doses. Methods: The torso CT was segmented into six distinct regions using TotalSegmentator. An automated program was employed to extract the necessary information and calculate the effective dose (ED) of PET/CT. The accuracy of our automated program was verified by comparing the EDs calculated by the program with those determined by a nuclear medicine physician (n = 30). Additionally, we compared the EDs obtained from an older PET/CT scanner with those from a newer PET/CT scanner (n = 42). Results: The CT ED calculated by the automated program was not significantly different from that calculated by the nuclear medicine physician (3.67 ± 0.61 mSv and 3.62 ± 0.60 mSv, respectively, p = 0.7623). Similarly, the total ED showed no significant difference between the two calculation methods (8.10 ± 1.40 mSv and 8.05 ± 1.39 mSv, respectively, p = 0.8957). A very strong correlation was observed in both the CT ED and total ED between the two measurements (r2 = 0.9981 and 0.9996, respectively). The automated program showed excellent repeatability and reproducibility. When comparing the older and newer PET/CT scanners, the PET ED was significantly lower in the newer scanner than in the older scanner (4.39 ± 0.91 mSv and 6.00 ± 1.17 mSv, respectively, p < 0.0001). Consequently, the total ED was significantly lower in the newer scanner than in the older scanner (8.22 ± 1.53 mSv and 9.65 ± 1.34 mSv, respectively, p < 0.0001). Conclusions: We successfully developed an automated program for calculating the ED of torso 18F-PET/CT. By integrating a deep learning model, the program effectively eliminated inter-operator variability.

Aim: This study aims to estimate equivalent doses (EqDs) and life attributable risks (LARs) for pediatric patients who underwent chest–abdominal–pelvic (CAP) CT examinations in Madinah, Saudi Arabia. Methodology: This retrospective study collected data from 120 pediatric patients who underwent CAP CT examinations. The data were categorized by the age and gender of the pediatric patients. Then, the EqDs were computed using the NCICT (National Cancer Institute dosimetry system for computed tomography) program, and LARs were estimated from the equivalent dose (EqD) results using age- and gender-specific cancer risk models found in the Committee on the Biological Effects of Ionizing Radiation (BEIR) VII Phase 2 (2006). Results: The EqD range was 0.9 to 7.55 mSv for the prostate and colon (males and females), respectively. LARs for female breast and lung cancers were considered to have the highest values among the age groups. Nevertheless, LARs of the colon, liver, and leukemia cancers were higher for males than females. The LAR range of cancer incidence was 0.6 to 63.1 per 100,000 cases for prostate (aged 10–≤15 years) and breast (females aged 1≤–

Computed tomography has become increasingly common for diagnosing socially significant diseases in recent years. In foreign practice, screening schemes for lung cancer in people belonging to risk categories have been developed and implemented. These schemes have been successfully used over the past 10 years. In this case, “low-dose” scanning protocols are used, which make it possible to perform examination with patient effective dose several times lower compared to standard protocols. Lung cancer screening methods using low-dose computed tomography are beginning to be introduced in the Russian Federation. To ensure the radiation safety of those individuals eligible for inclusion in screening programs or participating in biomedical research testing lung cancer screening, it is necessary to evaluate effective doses from low-dose computed tomography and compare these doses to established radiation dose limits. This study assessed the patients’ effective doses who underwent different types of low-dose computed tomography of chest at two medical organizations. The results of the study show that it is possible to achieve non-exceedance of the current annual effective dose limit of 1 mSv only for patients weighing less than 90 kg. For patients with higher body weight, the minimum effective dose will be in the range of 1.2 – 1.4 mSv. The results of the study indicate the need to make changes to the current regulatory and methodological documents of Rospotrebnadzor to ensure the possibility of using low-dose computed tomography as part of screening for all categories of people.

The practical implementation of radiation protection principles in the medical exposure of patients often tends to fall into one of two extremes: either excessive simplification of the methodology for assessing radiation health detriment, or its excessive complexity. An example of an excessively simplified approach is the assessment of radiation risk to patients using effective dose and radiation damage coefficients (nominal risk coefficients) as presented in Norms of the Radiation Safety NRB-99/2009. An example of an unjustifiably complex approach can be considered Tables 1-2 in MR 2.6.1.0215-20 "Assessment of radiation risk to patients during X-ray diagnostic radiological examinations," which indicate "lifetime risk values of death taking into account harm from reduced quality of life due to cancer of various organs and tissues and genetic effects from medical examinations" for a wide range of medical diagnostic X-ray radiological examinations in five-year age groups of patients. The main shortcomings of the simplified approach can be considered the lack of differences in risk assessment between individuals of different sexes and ages, although the fact of higher radiosensitivity in children compared to adults and in women compared to men can be considered universally recognized. The risk assessment approach proposed in MR 2.6.1.0215-20 addresses these shortcomings. However, in the view of the authors of this study, it offers an unnecessarily detailed picture considering uncertainties inherent in risk assessments at low doses, as well as uncertainties in the method of interpopulation transfer of radiation risk proposed by the International Commission on Radiological Protection. The aim of this study was to develop and justify a simpler and more straightforward method of presenting information on radiation risks associated with medical X-ray radiological examinations, free from the main drawbacks of the two aforementioned methods. To achieve this goal, radiation risks were calculated using two methods (using effective dose and using the risk model of the International Commission on Radiological Protection). A comparative analysis of the calculation results was conducted with estimates presented in Tables 1-2 of MR 2.6.1.0215-20. As a result of the analysis, an original applied method for presenting qualitative characteristics of radiation risks was developed for use in prescribing X-ray radiological examinations and informing patients about potential health risks. The practical outcome of the study is the formation of a table of radiation risks associated with conducting studies on patients from the Russian population, using the developed method of presenting information on radiation risks.

A model of occupational exposure to gamma flaw detector operators working with portable flaw detectors in the field has been developed. The initial data for the development and verification of the model were the results of measurements of the characteristics of the gamma radiation field at the workplaces of flaw detectors and data from individual dosimetric monitoring. The relationships between the measured (H*(10), Hp(10)) and protection (effective dose) quantities (conversion coefficients) were determined using calculations and phantom experiments simulating three main operations of the full production cycle: transportation of the flaw detector to the place of X-raying of the product, installation of a flaw detector to perform x-raying and X-raying of the product. As a result of the study, it was found that more than 90% of the dose contribution to the readings of an individual dosimeter is due to the installation of the flaw detector in the working position and X-raying of the product. The values of the conversion coefficients for these operations in the form of the ratio of the effective dose values and the readings of dosimeters (Hp(10)) located on the worker's body at chest level (standard place) and abdominal level differ little for both positions of individual dosimeters. The use of maximum conversion coefficient value of 0.8 Sv/Sv corresponding to the operation of X-raying of the product will ensure conservatism in the assessment of the effective dose for the entire production cycle by no more than 15% and 25% for dosimeters located at the chest level and abdominal level, respectively.

Diagnostic reference levels are one of the effective tools for optimizing patient radiation doses in diagnostic radiology. The staff of domestic radiology departments does not have an understanding of the development process and use of diagnostic reference levels during X-ray examinations, although this tool is a generally accepted in practice abroad. The article shows the experience of forming regional diagnostic reference levels based on measurements provided by the accredited testing laboratory of the Scientific and Practical Clinical Center for Diagnostics and Telemedicine Technologies of the Moscow Healthcare Department. The diagnostic reference levels for radiography in Moscow were developed for eight of the most common types of examinations based on the operation of 216 digital X-ray machines. The resulting levels, expressed in the dose-area product (cGy-cm2) and effective dose (mSv), were compared with the local diagnostic reference levels for the Ryazan region, Russia, and national diagnostic reference levels for other countries. The analysis showed continuity in the values. Some types of studies have been optimized. The developed diagnostic reference levels are the quality performance indicators foe diagnostic radiology departments and will be used to optimize a patient radiation dose during diagnostic studies in Moscow.

The paper provides an assessment of the probability and consequences of external events capable of leading to an incident with a breach of established safety barriers restricting the spread of radioactive substances along the coastline of the Techensky reservoir cascade. The initiating events for such an incident could be adverse meteorological conditions resulting in a decrease in the water level in the cascade water bodies below the specified design levels. Drying out the surface of previously inundated sections of the coastline will create an extensive source of atmospheric contamination by technogenic radionuclides during wind-induced resuspension. The probable area of the dried-out sections will be 0.02 — 0.08 kml for reservoir V-3, 0.06 — 0.28 kml for reservoir V-4, 0.19 — 0.90 kml for reservoir V-10, and 0.47 — 2.19 kml for reservoir V-11. The cumulative inventory of 137Cs and 90Sr in the specified area exceeds 105 Bq/ml. The activity released into the atmosphere within an hour will range from 3.69∙108 to 8.48∙1011 Bq for the wind speeds of 5 m/s and 20 m/s, respectively. The probabilities of joint occurrence of strong winds and drought conditions are 6.8∙10-7 per year for a wind speed of 20 m/s and 2.1∙10-3 per year for a wind speed of 5 m/s. The highest values of effective dose for the population of the nearest settlements, reaching 1-3 μSv in the first 10 days and over 200 μSv in the first year, are achieved under extreme wind loads with wind speeds of 20 m/s or more.

Abstract This study aims to measure radon gas concentration, calculate the annual effective dose, and calculate excess lung cancer risk in KufrKhal-Jerash north of Jordan. Radon is a radioactive gas located everywhere and contributes more than 40% of people’s total dose from natural radiation. The Risk concerns have resulted from the increase in mortality due to lung cancer in KufrKhal. About 117 well-calibrated dosimeters were among the study area’s districts (Hill 1, Hill 2, Hill 3, and village center). Each dosimeter consists of a plastic cup with known dimensions and a piece of solid state nuclear track detector (SSNTD) type CR-39 fixed in the inner bottom of the cup. After 90 days, the retrieved detectors were chemically etched, and the track density (tracks.cm−2) was determined. The results showed that the average radon concentrations drastically varied between the districts of KufrKhal (17.1–128.8 Bqm−3). However, the mean radon values in different districts are closely related (64.4–75.5 Bq.m−3). The lowest concentration (17.1 Bqm−3) was found in the Hill 1 district, and the highest value (128.8 Bqm−3) was found in the village center. However, the overall radon concentration in KufrKhal was approximately 69.2 Bqm−3. This value is within the range of the national average level (43.2 – 77.4 Bq.m−3) and way below the national action level (200 Bq.m−3). Furthermore, the corresponding values of the annual effective dose (AED) and the excess lung cancer risk (ELCR) for dwellers in this village were calculated to be 1.8 mSv.y−1 and 0.2%, respectively. These values, according to Jordan’s national regulations are acceptable.

Abstract Background Chronic insomnia disorder is a common sleep disorder. Previous studies have reported increased demand for anesthetics in patients with chronic insomnia disorder. However, few studies have investigated the effective dose of dexmedetomidine for sedation in patients with chronic insomnia disorder. We aimed to determine the 95% effective dose of dexmedetomidine to induce adequate sedation in patients with chronic insomnia disorder. Methods This is a biased coin design up-and-down sequential allocation trial in patients aged 18–65 years with chronic insomnia disorder (n = 60). The dose of dexmedetomidine for the subsequent patient was determined based on the response of the previous patient, with an interval of 0.1 µg/kg. Sedation was assessed using the bispectral index. The 95% effective dose was calculated using isotonic regression. Results The 95% effective dose of dexmedetomidine to induce adequate sedation in patients with chronic insomnia disorder was 1.75 (95% confidence interval, 1.70–1.94) µg/kg. Four patients (6.7%) experienced bradycardia and no other adverse events were observed during the study. Conclusions The 95% effective dose of dexmedetomidine to induce adequate sedation in patients with chronic insomnia disorder was 1.75 µg/kg. Trials registration Chinese Clinical Trial Registry (ChiCTR2200063212); first registered 01/09 /2022.

Objectives Vascular and interventional radiology procedures are characterized by high exposure of personnel to ionizing radiation. This study assessed the exposure of medical personnel to ionizing radiation during vascular radiology and mechanical thrombectomy procedures. Material and Methods During vascular radiology procedures, the exposure of 4 groups of workers participating in the procedures was analyzed, i.e., the main operating physician, an assistant physician, a sterile nurse, and a nurse. Measurements of exposure to ionizing radiation were performed using thermoluminescent dosimetry. Results The registered effective dose during 1 treatment in individual groups is, respectively: mean (M) ± standard deviation (SD) 75±15 μSv, 24±5 μSv, 13±3 μSv, and 8±2 μSv. During mechanical thrombectomy, the operating physician receives an effective dose of M±SD 9±2 μSv. The equivalent doses for the lenses for the operating physician and the doctor assisting during vascular radiology procedures are M±SD 1419±285 μSv and 987±198 μSv, respectively, and for the hands, including the left and right hands, M±SD 4605±930 μSv, 1420±284 μSv, 1898±380 μSv, 1371±274 μSv. Conclusions If the principles of optimizing radiological protection are not applied during vascular radiology procedures, the permissible dose limits and operational limits equivalent to doses to lenses and hands may be exceeded. Exposure during vascular radiology procedures is comparable to exposure during nuclear medicine procedures in terms of the use of glucose labeled with radioactive fluorine. Int J Occup Med Environ Health. 2024;37(4):403–10

Abstract Background One of the most common congenital conditions detected globally, congenital heart diseases, and CT techniques provide a high-quality and thorough presentation of heart anatomy, thoracic vasculature, and extracardiac structures, and hence, it is becoming a more popular non-invasive diagnostic imaging method for congenital heart disease. The drawbacks with CT imaging are the radiation exposure from repeated scans is also rising, especially in young patients. The present study is aimed to evaluate the radiation dose in gated and non-gated cardiac CT for preoperative diagnosis of pediatric patients with congenital heart diseases. Results A total of 111 pediatric patients with mean age of 7.47 years were prospectively included in the study. The mean value of “Effective dose (E)” for gated CT at $$100\;{\text{kV}}_{{\text{p}}}$$ 100 kV p was found to be $$4.71\;{\text{mSv}}$$ 4.71 mSv which is higher than mean “E” of $$3.95\;{\text{mSv}}$$ 3.95 mSv observed for gated CT at $$80\;{\text{kV}}_{{\text{p}}}$$ 80 kV p . The average value of “E” for non-gated technique was observed less than that of gated technique at both $$100\;{\text{kV}}_{{\text{p}}}$$ 100 kV p and $$80\;{\text{kV}}_{{\text{p}}}$$ 80 kV p . The multiple regression analysis shows that “E” is significantly dependent on $${\text{DLP}}\left( {{\text{mGy}}\;{\text{cm}}} \right)$$ DLP mGy cm for both gated and non-gated techniques at 95% level of significance $$\left( {p < 0.05} \right)$$ p < 0.05 . The Student’s t-test verifies that the mean value of “E” for both the techniques at $$100\;{\text{kV}}_{{\text{p}}}$$ 100 kV p and $$80\;{\text{kV}}_{{\text{p}}}$$ 80 kV p are significantly different at 95% level of significance $$\left( {p < 0.05} \right)$$ p < 0.05 . Conclusions The effective dose received by pediatric patients is much higher when using ECG-gated acquisition with an average value of $$4.71\;{\text{mSv}}$$ 4.71 mSv and $$3.95\;{\text{mSv}}$$ 3.95 mSv at $$100\;{\text{kV}}_{{\text{p}}}$$ 100 kV p , and at $$80\;{\text{kV}}_{{\text{p}}}$$ 80 kV p respectively. Because low-voltage X-rays are more sensitive to high atomic number iodinated contrast media, the mean “E” for non-gated cardiac CT imaging at $$80\;{\text{kV}}_{{\text{p}}}$$ 80 kV p is $$2.26\;{\text{mSv}}$$ 2.26 mSv , and results in significant reduction of effective dose.

Xiao-Dong Huang,1,&ast; Jia-Bao Chen,2,&ast; Xiao-Yun Dong,1 Wei-Long Wang,1 Jin Zhou,1 Zhen-Feng Zhou1 1Department of Anesthesiology, Hangzhou Women’s Hospital (Hangzhou Maternity and Child Health Care Hospital, Hangzhou First People’s Hospital Qianjiang New City Campus, Zhejiang Chinese Medical University), Hangzhou, People’s Republic of China; 2Department of Anesthesiology, Zhejiang Provincial People’s Hospital (People’s Hospital of Hangzhou Medicine College), Hangzhou, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Zhen-Feng Zhou, Department of Anesthesiology, Hangzhou Women’s Hospital (Hangzhou Maternity and Child Health Care Hospital, Hangzhou First People’s Hospital Qianjiang New City Campus, Zhejiang Chinese Medical University), Hangzhou, 310008, People’s Republic of China, Tel +86-571-56005077, Email zhenfeng9853@163.comPurpose: This study aimed to investigate the influence of fentanyl on the effective dose of remimazolam-induced sedation in elderly female patients undergoing general anesthesia.Patients and Methods: Sixty female patients aged 65– 80 years undergoing selective general anesthesia were randomized into two groups: Group R+F received an initial dose of remimazolam (7.5 mg) with fentanyl (1 μg/kg), while Group R received remimazolam alone. Dosing adjustments (± 2.5 mg) were made based on the response of the preceding patient using the up-and-down allocation technique. The ED50 and ED95 were calculated using a sequential formula and probit regression. Probit regression was also used to assess the relative potency of remimazolam between groups. Sedation levels were evaluated using the Modified Observer’s Assessment of Alertness/Sedation (MOAA/S) scale.Results: The ED50 for remimazolam was significantly lower in Group R+F compared to Group R (p= 0.007). Probit regression estimated the ED50 and ED95 values for Group R+F at 4.878 mg (95% CI, 3.845– 5.859) and 8.184 mg (95% CI, 6.636– 13.546), respectively. In contrast, Group R demonstrated ED50 and ED95 values of 6.733 mg (95% CI, 5.533– 8.068) and 11.298 mg (95% CI, 9.101– 19.617), respectively.Conclusion: This study provides compelling evidence that the administration of 1 μg/kg of fentanyl significantly reduces the required sedative dose of remimazolam by approximately 30% during induction in elderly patients. Importantly, the concomitant use of 1 μg/kg of fentanyl does not increase the risk of adverse effects such as hypotension, respiratory depression.Keywords: remimazolam, fentanyl, effective dose, elderly

Imaging techniques, such as computed tomography (CT) and fluoroscopy, are essential for the diagnosis and treatment of urolithiasis. There is increasing concern regarding the cumulative radiation dose associated with medical imaging and its adverse effects. This study aimed to assess radiation exposure in patients undergoing endoscopic management of urolithiasis and to identify factors associated with increased exposure. A retrospective analysis of all consecutive symptomatic urolithiasis cases who underwent endoscopic surgery over a two-year period at a tertiary referral center was performed. The cumulative radiation dose was recorded per stone episode, and the effective dose (ED) then calculated. Multivariable regression analysis was performed to determine the association between ED and patient, stone, and procedural characteristics. Between January 2020 and December 2021, 250 patients underwent endoscopic intervention for urolithiasis; 71% (n = 178) were male with a median age of 48 years (IQR 35–59). The median stone size was 6 mm (IQR, 5–8 mm) and the median stone volume was 110 mm3 (IQR, 60–206 mm3). Most stones were located in the distal ureter (46%, n = 114). The median ED received per stone episode was 3.99 mSv (IQR 2.9–7 mSv). On multivariable analysis, BMI, number of CT scans performed, CT protocol used, and repeat procedures strongly predicted increased radiation dose (p < 0.01). It is important for urologists to consider the cumulative radiation dosage in patients with urolithiasis. Strategies to minimize exposure, such as avoiding re-imaging, low-dose CTs, and collimation of the region of interest with judicious magnification, should be considered during treatment. [ABSTRACT FROM AUTHOR]

Background: Chronic insomnia disorder is a common sleep disorder. Previous studies have reported increased demand for anesthetics in patients with chronic insomnia disorder. However, few studies have investigated the effective dose of dexmedetomidine for sedation in patients with chronic insomnia disorder. We aimed to determine the 95% effective dose of dexmedetomidine to induce adequate sedation in patients with chronic insomnia disorder. Methods: This is a biased coin design up-and-down sequential allocation trial in patients aged 18–65 years with chronic insomnia disorder (n = 60). The dose of dexmedetomidine for the subsequent patient was determined based on the response of the previous patient, with an interval of 0.1 µg/kg. Sedation was assessed using the bispectral index. The 95% effective dose was calculated using isotonic regression. Results: The 95% effective dose of dexmedetomidine to induce adequate sedation in patients with chronic insomnia disorder was 1.75 (95% confidence interval, 1.70–1.94) µg/kg. Four patients (6.7%) experienced bradycardia and no other adverse events were observed during the study. Conclusions: The 95% effective dose of dexmedetomidine to induce adequate sedation in patients with chronic insomnia disorder was 1.75 µg/kg. Trials registration: Chinese Clinical Trial Registry (ChiCTR2200063212); first registered 01/09 /2022. [ABSTRACT FROM AUTHOR]

Radiation exposures as a result of one's occupation can be incurred from planned activities, natural sources, or emergency situations. These exposures have to be monitored, controlled, and recorded for the radiation safety and protection of the workers. This paper investigates the annual radiation exposures of workers in the Philippines, its profiles in the last 10 years, and how it impacts the system of radiation protection in the country. In particular, the temporal trend of the distribution of workers monitored for different types of practices and the exposure levels from 2013-2022 was studied. It also investigated whether the existing provisions for monitoring occupational exposures are in accordance with international safety standards or whether there are still gaps that need to be addressed. The data of occupationally exposed workers in the study were obtained from the PhilDose registry of the Radiation Protection Service Section of the Philippine Nuclear Research Institute. The dosimeters used for whole-body monitoring are Thermo Scientific Harshaw thermoluminescent dosimeters and optically stimulated luminescence dosimeters. Results show that practices that have individual monitoring programs were mainly from medical applications, particularly in 2022, which accounted for more than 90% of the facilities. Results also show that occupational exposures were generally within the prescribed dose limits, but practices in industrial radiography, nuclear medicine, and interventional radiology had workers receiving doses exceeding the limits. The dose profiles in the industry also differed from that in medicine. The median annual doses and their dispersion in terms of interquartile range in industry and service facilities were higher compared to those in the medical sectors. The exposure profiles also showed an increasing trend in the median doses of workers in the medical sectors and a decreasing trend in the industry. The implications of the trends on the radiation protection systems in the country are also discussed. Among the gaps in occupational exposure monitoring identified are the lack of monitoring of those working with natural radiation sources (e.g. radon), limited coverage of neutron dose monitoring, and the need to enhance the application of the graded approach in occupational exposure monitoring. This study, thus, provides the current status and trends of occupational radiation exposures in the country, its impact on occupational radiation protection, and the gaps that need to be addressed for the strengthened protection of the workers. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to compare the effective doses among 16, 64, and 128-slice computed tomography (CT) scanners. Several strategies have been implemented to reduce the radiation dose from CT, including a low tube voltage, a high pitch protocol, automatic tube current modulation, and iterative reconstruction algorithms. These strategies have reduced the radiation dose from the previously reported >20 mSv to <3–5 mSv or even <1 mSv. This study compared the radiation doses associated with routine CT scans performed using various multi-slice CT scanners. Materials and Methods: A total of 330 patients who underwent CT scans as part of their routine clinical diagnoses from December 4, 2018, to March 26, 2019, were screened cross-sectionally. CT scans were performed using 16-slice GE HealthCare BrightSpeed, 64-slice GE HealthCare Discovery CT750 HD, and 128-slice Siemens Healthineers SOMATOM Definition Flash CT scanner systems. The parameters considered in the analysis were age, sex, body region, scanner type (16, 64, and 128 slices), dose length product, and the estimated mean ED. The effective radiation dose was calculated using the dose length product and compared among the scanner types. Results: We evaluated the CT scans of 166 men (50.3%) and 164 women (49.7%) patients. Among the three types of CT scanners used, the 16-slice CT scanner had the highest effective radiation dose for brain (P = 0.024), paranasal sinus (P = 0.027), cervical spine (P = 0.04), chest (P < 0.001) and pelvis (P = 0.014). Conclusion: The 16-slice CT scanner has the highest effective radiation dose compared to the 64 and 128-slice scanners. When performing routine CT scans with low-end CT scanner systems, dose-reduction strategies should be considered. [ABSTRACT FROM AUTHOR]

This study aims to measure radon gas concentration, calculate the annual effective dose, and calculate excess lung cancer risk in KufrKhal-Jerash north of Jordan. Radon is a radioactive gas located everywhere and contributes more than 40% of people's total dose from natural radiation. The Risk concerns have resulted from the increase in mortality due to lung cancer in KufrKhal. About 117 well-calibrated dosimeters were among the study area's districts (Hill 1, Hill 2, Hill 3, and village center). Each dosimeter consists of a plastic cup with known dimensions and a piece of solid state nuclear track detector (SSNTD) type CR-39 fixed in the inner bottom of the cup. After 90 days, the retrieved detectors were chemically etched, and the track density (tracks.cm−2) was determined. The results showed that the average radon concentrations drastically varied between the districts of KufrKhal (17.1–128.8 Bqm−3). However, the mean radon values in different districts are closely related (64.4–75.5 Bq.m−3). The lowest concentration (17.1 Bqm−3) was found in the Hill 1 district, and the highest value (128.8 Bqm−3) was found in the village center. However, the overall radon concentration in KufrKhal was approximately 69.2 Bqm−3. This value is within the range of the national average level (43.2 – 77.4 Bq.m−3) and way below the national action level (200 Bq.m−3). Furthermore, the corresponding values of the annual effective dose (AED) and the excess lung cancer risk (ELCR) for dwellers in this village were calculated to be 1.8 mSv.y−1 and 0.2%, respectively. These values, according to Jordan's national regulations are acceptable. [ABSTRACT FROM AUTHOR]

Hydrothermal resources are used for health prevention and treatment worldwide based on drinking, bathing, and immersing in thermal mineral waters. In some places, 222Rn inhalation is also present. In Brazil, several locations apply thermal and hydrotherapies integrated into the Unified Health System as in Águas de Lindóia and Thermas Antonio Carlos in Poços de Caldas Town. The effective dose due to 222Rn inhalation by the public and balneary workers, as well as the chemical and radiological characterization for these spas were evaluated. 222Rn activity concentration was measured by using CR-39, elemental water composition by neutron activation, and radionuclides, by gamma espectrometry. Results showed that the 222Rn activity concentration varied from 21 to 71 Bq m−3 in the public areas of the balnearies and from 407 to 16,451 Bq m−3 in the closed springs. Effective doses varied from 0.01 to 0.02 mSv y−1 for the public, from 0.10 to 0.33 mSv y−1 for works and from 0.03 to 4.95 mSv y−1 for maintenance. No risk occurs for members of the public and workers due to radon inhalation, but care must be taken on behalf of the maintenance workers from Águas de Lindóia balneary. The water, for both balnearies, do not exceed the recommendation for drinking water for gross alpha and gross beta activities. Chemically, the water from Águas de Lindóia is classified as hypo saline and the water from Poços de Caldas, as low mineral content. [ABSTRACT FROM AUTHOR]

In this study, the activity concentration of artificial and natural radionuclides such as 137Cs, 40K, 226Ra, and 232Th was measured in the soil under the roots; leaves; and fruits of six different fruit trees namely mulberry, fig, apricot, olive, black and white grapes in Koya district, Erbil province, Iraq. For this purpose, a high-resolution gamma spectroscopy consisting of a high-purity germanium (HPGe) detector was used. In addition, the associated radiological risks from soil and fruits were assessed by calculating several radiological indices such as radium equivalent (Raeq.s), absorbed dose (Ds), indoor (AEDEsindoor) and outdoor annual effective doses (AEDEsoutdoor), internal and external hazard indices, gamma index and the excess lifetime cancer risk (ELRCs). The results show that consuming these fruits is radiologically safe because they can cause an annual effective dose of about 61.72 μSv y−1 and excess lifetime cancer risk of 0.06 × 10−3 Sv y−1. On the other hand, transfer factors of radionuclides from soil to leaves; and from soil to fruits were studied. The transfer factor analysis revealed that among the studied fruits and radionuclides, apricot and mulberry exhibited the highest transfer factors for 40K, with values of 1.85 and 1.87, respectively. [ABSTRACT FROM AUTHOR]

Background: One of the most common congenital conditions detected globally, congenital heart diseases, and CT techniques provide a high-quality and thorough presentation of heart anatomy, thoracic vasculature, and extracardiac structures, and hence, it is becoming a more popular non-invasive diagnostic imaging method for congenital heart disease. The drawbacks with CT imaging are the radiation exposure from repeated scans is also rising, especially in young patients. The present study is aimed to evaluate the radiation dose in gated and non-gated cardiac CT for preoperative diagnosis of pediatric patients with congenital heart diseases. Results: A total of 111 pediatric patients with mean age of 7.47 years were prospectively included in the study. The mean value of "Effective dose (E)" for gated CT at 100 kV p was found to be 4.71 mSv which is higher than mean "E" of 3.95 mSv observed for gated CT at 80 kV p . The average value of "E" for non-gated technique was observed less than that of gated technique at both 100 kV p and 80 kV p . The multiple regression analysis shows that "E" is significantly dependent on DLP mGy cm for both gated and non-gated techniques at 95% level of significance p < 0.05 . The Student's t-test verifies that the mean value of "E" for both the techniques at 100 kV p and 80 kV p are significantly different at 95% level of significance p < 0.05 . Conclusions: The effective dose received by pediatric patients is much higher when using ECG-gated acquisition with an average value of 4.71 mSv and 3.95 mSv at 100 kV p , and at 80 kV p respectively. Because low-voltage X-rays are more sensitive to high atomic number iodinated contrast media, the mean "E" for non-gated cardiac CT imaging at 80 kV p is 2.26 mSv , and results in significant reduction of effective dose. [ABSTRACT FROM AUTHOR]

Introduction: Chest radiography is a frequently performed examination, and therefore, accurate patient dosimetry is important. One means of increasing dosimetric accuracy is through the use of size-specific dosimetry, and the aim of this work was to determine which patients would benefit from such a methodology applied in chest posterior-anterior (PA) projection radiography. Methods: A database of 44 voxel models was created from CT scans, representing adults with BMI from underweight, normal, overweight, and obese classes. Monte Carlo simulation was performed to generate dose conversion factors for each model. Correlation curves of the dose conversion factors with water equivalent diameter (WED) of the 44 voxel phantoms were obtained. A total of 8,536 chest PA examinations acquired between 2015 and 2019 using three X-ray systems were then retrospectively collected; 4,748 men (median age: 61 ± 21 years) and 3,788 women (median age: 60 ± 23 years). The WED of the patients was estimated from the ratio of detector air-kerma to incident air-kerma, using parameters in the DICOM header of the images. For all patients, a size-specific conversion factor was selected automatically using the relation between WED and dose conversion factor determined for the phantoms. The size-specific organ doses and effective doses were calculated based on these conversion factors, and then compared to the standard effective dose calculation with a paired test. Results: The lung doses ranged from 7 μGy to 96 μGy and had a good correlation with patient size in terms of WED (p < 0.01, R² between 0.52 and 0.77). The doses for thyroid ranged from 2 μGy to 42 μGy and correlated strongly with the patient size (p < 0.01, R² between 0.65 and 0.85). Breast doses ranged from 2 μGy to 13 μGy, and the correlation with the patient size was weak (p < 0.01, R² between 0.01 and 0.28). The size-specific effective dose ranged from 4 μSv to 42 μSv. The difference between the size-specific and standard effective dose ranged from -35% to 69% (p < 0.01), with differences exceeding ± 20% for 37% of the cases. Discussion: In conclusion, the method presented in this study enables automated size-specific dosimetry, within the proposed maximum deviation of ± 20%, and should be considered for routine application. [ABSTRACT FROM AUTHOR]

Understanding radon‐prone areas is vital to prevent radon‐related health problems, enhance public safety, and ensure adherence to regulations aimed at minimizing radon exposure. We conducted a comprehensive review of cross‐sectional studies reporting on residential radon exposure in Iran. Our review encompassed studies published until February 13, 2022. Out of the 966 articles initially identified, 37 studies were included in our analysis, which measured indoor radon levels in a total of 3480 residential buildings in Iran. Notably, the highest residential radon levels (Bq.m−3) were found in Mazandaran province, with the most hazardous recorded levels in Talesh Mahalleh (3235), followed by Ramsar (1299). Conversely, Tehran, the capital city of Iran, had the lowest recorded levels of residential radon, at 11.0 Bq.m−3. Remarkably, indoor radon concentration exceeded both the reference levels recommended by the World Health Organization (WHO) and the standard levels set by the U.S. Environmental Protection Agency (US.EPA), with approximately 51% and 26%, respectively. The mean effective doses received by Iranian residents were 5.0 mSv.y−1 (0.3–81.7). Moreover, the mean excess lifetime cancer risk (ELCR) associated with indoor radon exposure was determined to be two per 1000 people. The annual incidence of lung cancer cases (LCCs) per million people attributed to indoor radon exposure in Iranian residential buildings ranged from 5.00E − 06 to 1.47E − 03. The included studies addressed a wide range of variables affecting radon levels, but they did not cover all factors comprehensively. These factors encompass the meteorological parameters, geological characteristics, building construction materials, building type, window type, occupancy information, and ventilation rates in enclosed spaces. The potential health risks associated with indoor radon exposure necessitate the implementation of effective control measures. These should include raising public awareness, revising construction regulations, enhancing ventilation systems, identifying high‐risk areas, and conducting more comprehensive studies to better understand the factors that influence radon concentration. [ABSTRACT FROM AUTHOR]

The equilibrium factor F is one of the parameters that should be considered when assessing the effective dose based on radon activity concentration. Since the equilibrium factor in various environments ranges theoretically from a value close to 0 to 1, it is expected that dose assessment based on one recommended coefficient value may lead to an underestimation or overestimation of the dose. That is why it is essential to measure this quantity if the basis for dose assessment is the radon concentration and not the concentration of radon decay products. The equilibrium factors were determined based on measurements of radon activity concentration and potential alpha energy concentration and varied from 0.15 to 0.94, with an arithmetic mean of 0.55. The average effective dose calculated for the employee taking into account these values was 31 mSv, assuming an annual working time of 1800 h. In turn, the average effective dose calculated for the equilibrium factor of 0.2 as recommended by the International Commission on Radiological Protection (ICRP) was equal to 13 mSv. [ABSTRACT FROM AUTHOR]

Archive data (1970–2024) on the results of monitoring the tritium content of surface liquid radioactive waste (LRW) storage reservoirs (special radioactive waste repositories) and of groundwater in the vicinity of the Mayak Production Association are analyzed. The tritium contamination existing today was formed before the 1970s and was initially accumulated (a) in V-2 reservoir (Kyzyl-Tash), which operated as a reservoir for recirculating direct-cooling of industrial uranium–graphite reactors (PUGRs) in case of failure of uranium slug cladding; (b) in V-9 (Karachay) and V-17 (Staroye Boloto) reservoirs, which were used for storage of intermediate-level tritium-containing liquid waste; (c) in groundwater as a result of tritium seepage from the reservoirs. After putting into operation the RT-1 radiochemical plant (1977), the major fraction of tritium was accumulated in a new LRW type, tritium condensate, which was stored in V-17 reservoir. The contaminated groundwater filtering from V-17 reservoir was discharged only into an inlet of V-10 reservoir of the Techa Cascade of Reservoirs (TCR). The maximal rate of tritium discharge was estimated at 0.11 TBq/year, and the specific activity of tritium in the TCR water, at 2 Bq/L. In the 2020s, the tritium discharge into the atmosphere from the RT-1 plant was ~34 TBq, which was ~2800 times lower than the maximum permissible discharge prescribed for the whole enterprise. The mean value of the annual effective dose from all the pathways of tritium intake by Ozyorsk inhabitants was 0.26 μSv, and the maximal value was 0.49 μSv, which is ~2000 times lower than the dose limit of 1 mSv for the population. The tritium emissions and discharges from the RT-1 plant are negligible and exert virtually no radiation impact on the population. [ABSTRACT FROM AUTHOR]

In this research, the radon gas concentration was measured for samples from the water of the Euphrates River in the Hindia district of Karbala governorate. The selected collection locations were 30 different local ones on the river between the ancient and modern bridges, heading north and south, respectively; the distance between locations was 100 meters. The concentrations and effective dose of radon were measured using the RAD7 device technology. The highest value was for sample 21, where the effective dose was (0.00001752 Bq/m³). The same value for the effective dose was of sample 7. The lowest value was in sample 27, where the effective dose was (0 Bq/m³), the same value of sample 3. It was observed from the study that the remaining values of the samples ranged from sample 1 as the lowest value of the effective dose (0.0799 Bq/m³) and also for sample 2 and sample 15. The highest value was for samples 29 and 23, where the value of the effective dose was (0.00001314 Bq/m³). However, from observing the results, these values are within the internationally permissible limits according to the recommendations of US Environmental Protection Agency, which is 11 Bq/L. [ABSTRACT FROM AUTHOR]

The annual occupational doses for workers at the Ghana Research Reactor-1 facility were assessed for the period 2018–2021. The dose records of monitored staff were retrieved and analysis done for dose distribution and collective effective doses. Thermoluminiscent dosimeters were used to monitor the occupational exposures. The dosimeters were evaluated for the cumulative radiation dose levels using the Harshaw 6600 TLD reader system. Annual dose of 1.52 mSv/year was the maximum acquired by an individual. An annual average effective dose range of 0.20–1.36 mSv was determined for all workers. The annual total collective effective dose was established to be in the range of 0.40–10.08 man-Sv. The 20 mSv annual limit for occupational exposure was not exceeded for monitored workers. The assessment shows that the GHARR-1 facility, in terms of radiation health effects, is a favorable environment for workers since exposures are mostly below occupational exposure limit. [ABSTRACT FROM AUTHOR]

In this study, a comprehensive investigation was conducted to determine the radioactivity levels of naturally occurring radioactive materials (NORMs) in heap pads/soil and water samples within and around the operational area of Tarkwa Gold Mine in Ghana. Gamma-ray spectrometry was used to determine the activity concentrations of 238U, 232Th, and 40K in heap pads/soil, and 226Ra, 228Th, and 40K in water samples. The average activity concentrations of 226Ra and 228Th in all water samples were below the World Health Organisation (WHO) recommended guidelines for drinking water. Similarly, the average activity concentrations of measured radionuclides in heap pads/soil samples taken from depths of 0–20 cm and 20–50 cm were found to be below the worldwide average reported values. The annual effective dose to the public was estimated to be around 0.16 mSv, which is below the recommended limit. The values of the hazard indices are also below the recommended limits, implying that if heap pads/soils are used for building purposes and construction, they will not pose any significant radiation hazard. The results of this study indicate that radiation levels are within the natural background radiation levels reported in the literature and are consistent with findings from similar studies conducted in Ghana. [ABSTRACT FROM AUTHOR]

The epidemiological approach to converting radon exposure to effective dose is examined. Based on the definition of the effective dose, the dose conversion is obtained from the equivalence of lung-specific detriment associated with low-LET radiation and with radon exposure. This approach most reliably estimates effective dose per radon exposure on the basis of epidemiological data and implicitly includes the radiation weighting factor required to calculate the effective dose from radon exposure using the dosimetric approach, applying biokinetic and dosimetric models. Consistency between the results of the epidemiological and dosimetric approaches is achieved by using a radiation weighting factor of about 10 for alpha particles instead of the current ICRP value of 20. In contrast, the epidemiological approach implemented in ICRP 65, and referred to as dose conversion convention, was based on direct comparison of total radiation detriment with lung detriment from radon exposure. With the revision of radiation detriments in ICRP 103, this approach can be judged to overestimate the effective dose per radon exposure by about a factor of two because the tissue weighting factor for lung differs from the value of relative detriment to which it relates. [ABSTRACT FROM AUTHOR]

Assessing individual external exposure doses from ambient dose equivalents is valuable for predictive and retrospective purposes when personal dosimeters are impractical. This study developed a model to assess individual external exposure doses from ambient dose equivalents, considering daily life patterns (location and time spent in various places), and evaluated parameters associated with individual external exposure doses, such as the reduction effects of radiation due to buildings and vehicles. The model parameters were evaluated using the robust datasets of environmental radiation measured in areas affected by the Fukushima Daiichi Nuclear Power Station (FDNPS) accident. The effective dose estimated by the model was compared to 106 daily personal dose equivalents measured using personal dosimeters in the residents’ living environments near the FDNPS. The estimated effective dose well consists with the measured personal dose equivalents, particularly when considering natural radiation in indoor dose estimation. This model is adequate for radiation protection, enabling the predictive and retrospective estimation of individual external exposure doses using environmental radiation monitoring data.

Abstract The Moon lacks a global magnetic field and atmosphere, leaving its surface been directly exposed to high‐energy cosmic radiation. Sporadic Solar Particle Events are sources of a significant radiation exposure, potentially posing serious threats to the health of astronauts exploring the Moon. In this paper, we use the Radiation Environment and Dose at the Moon (REDMoon) model based on GEometry And Tracking (GEANT4) Monte‐Carlo method to calculate the body effective dose induced by 262 large historical SEP events on the Moon under different shielding depths which can result from the lunar regolith shielding and/or additional aluminum shielding. We calculate and compare the contributions of different particles from or produced by SEPs to the total body effective dose. Additionally, we develop empirical functions to rapidly assess SEP‐induced effective dose on the Moon under different shielding scenarios.

Continuous exposure to ionizing radiation can have harmful effects on human health. In this respect, a study was carried out in the Communes of Dassa-zoume and Glazoue to determine the levels of 40K, 238U and 232Th in granites and sand. The specific activities obtained made it possible to assess the possible radiological risks associated with the resident population. During sampling work in November 2022, twelve granite samples were taken from twelve quarries. In addition, a sand sample was collected in Cotonou for comparison. All samples were then sent to the INSTN-Madagascar laboratory for gamma-ray spectrometry analysis using a NaI(TI) detector. The results show that the average specific activities of 40K, 238U and 232Th in the granites are (1329 ± 128) Bq.kg-1, (44 ± 11) Bq.kg-1 and (129 ± 44) Bq.kg-1 respectively. Those in sand are (144 ± 8) Bq.kg-1, (30 ± 2) Bq.kg-1 and (56 ± 7) Bq.kg-1 respectively. The average equivalent radium activity is (330 ± 74) Bq.kg-1 versus (122 ± 10) Bq.kg-1 for sand. The mean gamma index for granite was (1.2 ± 0.3), compared with (0.43 ± 0.03) for sand. The average absorbed dose rate in air is (153.4 ± 9.4) nGy.h-1 versus (53.7 ± 5.1) nGy.h-1 for sand. For adults, for 80% building occupancy factor, the mean annual indoors and outdoors effective dose (E) inside a building are (0.75 ± 0.05) mSv.y-1 and (0.19 ± 0.01) mSv.y-1 versus (0.26 ± 0.05) mSv.y-1 and (0.07 ± 0.01) mSv.y-1 for sand. For 60% factor, the means are (0.56 ± 0.03) mSv.y-1 and (0.38 ± 0.02) mSv.y-1 versus (0.20 ± 0.01) and (0.13 ± 0.01) mSv.y-1 for sand. For the children, for a building occupancy factor of 80%, the average E are (0.86 ± 0.05) mSv.y-1 and (0.21 ± 0.01) mSv.y-1 versus (0.30 ± 0.01) mSv.y-1 and (0.08 ± 0.01) mSv.y-1 for sand respectively for indoors and outdoors. For infants, the E are (1.00 ± 0.06) mSv.y-1 and (0.25 ± 0.01) mSv.y-1 versus (0.35 ± 0.01) mSv.y-1 and (0.09 ± 0.01) mSv.y-1 for sand respectively for indoors and outdoors. For children, for a building occupancy factor of 60%, the average E are (0.64 ± 0.03) mSv.y-1 and (0.43 ± 0.02) mSv.y-1 versus (0.23 ± 0.01) mSv.y-1 and (0.15 ± 0.01) mSv.y-1 for sand respectively indoors and outdoors. For infants, for a building occupancy factor of 60%, the E are (0.75 ± 0.05) mSv.y-1 and (0.50 ± 0.02) mSv.y-1 versus (0.26 ± 0.01) mSv.y-1 and (0.18 ± 0.01) mSv.y-1 for sand respectively indoors and outdoors. For adults, the excess lifetime cancer risk at age 66 for a total annual effective dose induced by granite is (3.1 ± 0.01).10-3 versus (1.1 ± 0.01).10-3 for sand. For the children and infants, the average ELCR is (3.5 ± 0.01)E-3 and (4.1 ± 0.01)E-3 versus (1.2 ± 0.01)E-3 and (1.4 ± 0.01)E-3 for sand respectively. Statistical analysis of the data was performed with Python 3.11 and R 4.3.2 on the Spyder and studio interface. The p-value is < 0.001 compared with the UNSCEAR reference value for absorbed dose rate in air, effective dose and excess risk, which are 84 nGy.h-1, 0.48 mSv.y-1 and 0.29.10-3. This shows that the granites in the quarries studied present a radiological risk when used as building materials and need specific radiation protection measures for his users.