In short terms, a society's available resources are finite and must be prioritised. The more resources that are spent on radiological protection, the lesser resources are available for other needs. The ALARA principle states that exposure of ionising radiation should be kept as low as reasonably achievable, taking into account economic and societal factors. In practice, one of several approaches to determine what is considered as reasonably achievable is cost-benefit analysis. A demanding part of cost-benefit analysis is to decide on anvalue, which stipulates the value of radiological protection. There are different conversion methods on how to convert societal costs into anvalue. However, with the assistance of recent developments within both health economics and radiological protection room for improvements was found. Therefore, the aims of the present study were to develop a new conversion method (on how to convert societal costs into anvalue) and to provide recommendations ofvalues for each member country of The Organisation for Economic Co-operation and Development (OECD). With the help of systematic reviews of societal costs (the value of a statistical life, productivity losses and healthcare costs) and discount rates, as well as Monte Carlo simulations of the number of years between exposure and cancer diagnosis, a new conversion method and recommendations ofvalues could be presented. The new conversion method was expressed as a discounted nominal risk of exposure with a median (interquartile range) of 175 (136-222) per 10 000 persons per Sv for the public and 169 (134-207) per 10 000 persons per Sv for workers. For OECD in general, recommendations ofvalues were determined to be $56-170 per man.mSv for the public and $61-162 per man.mSv for workers (2023-USD).

This study investigated the additional radiation exposure, influencing factors, and clinical significance of overlapping-axis coverage in abdominopelvic CT scans performed consecutively after same-day chest CT scans. Data from 761 patients were analyzed, with measuring the total and overlapping-axis coverage of the portal venous phase in abdominopelvic CT scans. The average overlapping portion was 33.8 ± 12.1 mm, accounting for approximately 7.0% of the total scan length, contributing a dose-length product of 33.4 mGy*cm and an effective radiation dose of 0.5 mSv. Male sex and the total scan length were identified as significant factors influencing overlap (= 0.002 and < 0.001, respectively). Despite overlapping scans frequently imaging the lower lungs, only 8.4% of abdominopelvic CT reports specifically mentioned lower lung abnormalities, indicating limited clinical utility. These findings underscore the importance of optimizing CT protocols to minimize the total length of the body covered in abdominopelvic scans, thereby reducing unnecessary radiation exposure during concurrent chest and abdominopelvic CT scans.

Epidemiological studies of nuclear industry workers are of substantial importance to understanding the risk of cancer consequent to low-level exposure to radiation, and these studies should provide vital evidence for the construction of the international system of radiological protection. Recent studies involve large numbers of workers and include health outcomes for workers who accumulated moderate (and even high) doses over prolonged periods while employed during the earlier years of the nuclear industry. The interpretation of the findings of these recent studies has proved to be disappointingly difficult. There are puzzling patterns of results involving the period of first employment and monitoring for radionuclide intakes, depending on the particular study examined. Explaining these patterns is crucial for a reliable understanding of results in terms of occupational radiation exposure. In this paper, an updated review of nuclear worker studies is presented in the context of these patterns of results, making use of the latest relevant results. It is apparent that the strikingly raised risks for mortality from solid cancers for workers hired in later years reported from the International Nuclear Workers Study (INWORKS) is effectively confined to workers at five nuclear facilities in the USA, and that the notable variation of risks in INWORKS between workers monitored or not for radionuclide intakes is driven by UK workers. These are the areas where effort must be concentrated before a confident derivation of radiation risk estimates can be obtained from these nuclear worker studies. .

In this submission we opine on India adopting a rather stringent maximum single year dose limit, instead of harmonizing with international standards. We explore how dose limits evolved, why India has opted for a lower maximum effective dose limit of 30 mSv for a single year and argue that raising this limit to at least 50 mSv, in line with International Commission on Radiological Protection (ICRP) recommendations, would not only contribute to upcoming revised ICRP publications but also support the realization of India's nuclear ambitions.

With the International Commission on Radiological Protection (ICRP) lowering the annual dose limit for the eye lens to 20 mSv, precise monitoring of eye lens exposure has become essential. The personal dose equivalent at a depth of 3 mm,(3), is the measurement method for monitoring the dose to the lens of the eye. Usual dosemeter type-test irradiations at non-normal angles of radiation incidence (≠ 0°) primarily use lateral radiation exposure scenarios, where radiation approaches from the left or right, necessitating rotation of the dosemeter-phantom setup around a vertical axis. However, this method does not adequately account for bottom-to-top radiation exposures which are common in real-world situations (such as radiation scattered by a patient reaching medical staff). This study examines oblique radiation exposure conditions using a typical eye lens thermoluminescent dosemeter (TLD), Eye-D, placed on a cylindrical phantom to assess dose response at different angles and exposure energies. The study employs both low-energy (N-30 radiation quality with a mean photon energy of 25 keV) and medium-energy (N-100 radiation quality with a mean photon energy of 83 keV) x-rays at irradiation angles of60°, 0°, and +60°, measured along the vertical and horizontal rotation axes of the dosemeter-phantom setup. The results show no significant difference between horizontal and vertical (polar and radial) rotation orientations of the dosemeter-phantom setup: recorded relative doses stayed well within ± 1 %, i.e. by far within the attributed combined uncertainty of ± 2 %.

After the Fukushima Daiichi Nuclear Power Station accident, various information about radiation circulated throughout Japan, leading to diverse perceptions regarding the situation in Fukushima. These perceptions contributed to the social challenges faced by the residents of Fukushima at the time, including prejudice and discrimination. This heightened concern about radiation exposure, particularly among younger generations who were considering marriage or starting families. In the present study, we aimed to investigate the present status of radiation risk perception among university students in Japan and the factors associated with radiation risk perception among these students. A questionnaire survey was administered to university students throughout Japan. We collected demographic information as well as queried their perception of radiation risk (delayed health effects and genetic effects). The results showed that approximately 60% and 40% of respondents believed that delayed effects and genetic effects would occur among residents of Fukushima, respectively. Additionally, having a university major other than studying radiation techniques and living in western Japan were associated with these perceptions of risk. In the future, enhancing risk communication, especially among young populations in western Japan, is necessary to dispel anxiety about the risks from radiation exposure. .

The radium dial painters (RDP) are a well-described group of predominantly young women who incidentally ingested 226Ra and 228Ra as they painted luminescent watch dials in the first part of the twentieth century. In 1974 pathologist Dr. William D. Sharpe published complete clinical and autopsy results for 42 former radium dial painters evaluated in the New Jersey Radium Research Project (NJRRP). This was an important paper due to the completeness of the observations. Surprisingly, in this study, clinicians noted a 35.5% incidence of hearing loss, both conductive and mixed etiologies. Since the 1974 publication, there has developed a considerable literature on radiation-induced hearing loss in patients undergoing radiotherapy for head and neck cancers. It is expected that hearing loss would also be associated with systemic inflammation. Recently, the neutrophil to lymphocyte ratio (NLR) has been shown in many cancer and non-cancer studies to be a nonspecific marker of inflammation. In prior collaborative efforts with the United States Transuranium and Uranium Registries (USTUR) and with the NCRP Million Person Study, it has been possible to evaluate NLR from medical records of a cohort of 166 former radium dial painters previously evaluated at Argonne National Laboratory. In addition, NLR was available in historic medical records of the sarcoma and nasopharyngeal cancer patients described in Rowland's summary of the Argonne studies. . Using elevation of the neutrophil to lymphocyte ratio (NLR) as a non-specific marker of inflammation, chronic inflammation has been observed in all cohorts with significant dose. The RDP cohort has had a unique exposure to radium, but the incidence of radiation-induced hearing loss here is uncertain. Due to cosmic radiation dose to astronauts in space flight, there is a significant interest in high LET radiation dose to the brain, including the auditory system. .

Historically, radiation exposure to mineral sands workers arose primarily from intake of thorium associated with monazite dust generated in mineral separation plants. Research investigations in the 1990s provided greater insight into the characteristics of inhaled thorium ore dust and bioassay studies inferred that some workers had accumulated significant lung burdens of thorium. Recent changes to biokinetic models have increased the radiation dose assessed to arise from thorium intake, raising questions on the appropriateness of current assumptions used in exposure assessment and feasibility of further bioassay research. Past radiation research undertaken in the Western Australian mineral sands industry is summarised and findings from contemporary research relevant to thorium ore dust exposure, thorium health effects and the associated assessment of internal radiation dose are reviewed and analysed. Radiation exposures in the industry have reduced substantially in the last two decades, however current workplace exposure measurement regimes may not reflect the actual intake of monazite-bearing dusts on an individual basis. Past research indicated that thorium associated with monazite dust is relatively insoluble and avidly retained in the lung. There is a paucity of published research on thorium retention and excretion by mine workers over the last 20 years, however significant advances have been made in the detection of thorium in biospecimens. Improvements in measurement technology should make periodic bioassay measurements feasible for selected long-term workers involved in the mining and processing of naturally occurring radioactive materials. Past worker dose estimates require re-evaluation following recent updates to biokinetic models and long-term follow up of the health of workers chronically exposed to thorium ore dusts is recommended.

Although the Boundary Representation (BREP) method creates detailed surface phantoms of Chinese women of childbearing age, these phantoms cannot be directly used in Monte Carlo simulations. They must first be converted into voxel phantoms, a process that may diminish some of the inherent advantages of the surface phantoms. Therefore, the aim of this study is to construct a tetrahedral mesh (TM) phantom of Chinese women of childbearing age based on the BREP phantom, incorporating micron-level structural refinements to certain organ tissues while maintaining the original model's structure. This TM phantom can be directly implemented into Monte Carlo codes to calculate the absorbed dose at different photon energies, demonstrating that both the structure and position of organ tissues affect the radiation dose. By achieving more accurate dose assessments, we can optimize radiation protection measures and reduce the potential risks to women of childbearing age. .

Since 1968, the United States Transuranium and Uranium Registries (USTUR) has studied the biokinetics and tissue dosimetry of uranium and transuranium elements in nuclear workers. As part of the USTUR collaboration with the Million Person Study (MPS) of Low-Dose Health Effects, radiation dose to different parts of the human heart is being estimated for workers with documented intakes of 239Pu or 226Ra. The study may be expanded for workers with intakes of 238U and other radionuclides. The distribution of radionuclides, expressed in terms of concentration (Bq per kg of tissue) serves as an important parameter for estimating radiation dose. Based on available organs from workers who donated their bodies or tissues for research, nine undissected hearts were selected: seven from USTUR registrants with plutonium exposure (males) and two individuals with radium intakes (female and male). For the plutonium workers, estimated 239Pu systemic deposition ranged from <74 Bq to 1765 Bq. Estimated 226Ra 'initial systemic intakes' were 10.1 MBq and 14.8 kBq for the female patient and male worker, respectively. Organ dissection was based on a heart model published by Borrego et al (2019). This model includes nine cardiac substructures: aorta, left main coronary artery, left atrium, left anterior descending artery, left circumflex artery, left ventricle, right atrium, right coronary artery, and right ventricle. In addition, heart valves, fat attached to epicardium, fluids, and a coronary bypass graft were collected resulting in 111 samples that are currently undergoing radiochemical analyses and mass-spectrometric measurements. The 239Pu and 226Ra evaluations are not completed. The results of this study are intended to support radiation worker health studies by improving associated dosimetric and epidemiological models.

Artificial intelligence (AI) is transforming medical radiation applications by handling complex data, learning patterns, and making accurate predictions, leading to improved patient outcomes. This article examines the use of AI in optimising radiation doses for x-ray imaging, improving radiotherapy outcomes, and briefly addresses the benefits, challenges, and limitations of AI integration into clinical workflows. In diagnostic radiology, AI plays a pivotal role in optimising radiation exposure, reducing noise, enhancing image contrast, and lowering radiation doses, especially in high-dose procedures like computed tomography (CT). Deep learning (DL)-powered CT reconstruction methods have already been incorporated into clinical routine. Moreover, AI-powered methodologies have been developed to provide real-time, patient-specific radiation dose estimates. These AI-driven tools have the potential to streamline workflows and potentially become integral parts of imaging practices. In radiotherapy, AI's ability to automate and enhance the precision of treatment planning is emphasised. Traditional methods, such as manual contouring, are time-consuming and prone to variability. AI-driven techniques, particularly DL models, are automating the segmentation of organs and tumours, improving the accuracy of radiation delivery, and minimising damage to healthy tissues. Moreover, AI supports adaptive radiotherapy, allowing continuous optimisation of treatment plans based on changes in a patient's anatomy over time, ensuring the highest accuracy in radiation delivery and better therapeutic outcomes. Some of these methods have been validated and integrated into radiation treatment systems, while others are not yet ready for routine clinical use mainly due to challenges in validation, particularly ensuring reliability across diverse patient populations and clinical settings. Despite the potential of AI, there are challenges in fully integrating these technologies into clinical practice. Issues such as data protection, privacy, data quality, model validation, and the need for large and diverse datasets are crucial to ensuring the reliability of AI systems.

Paediatric patients with congenital heart disease often undergo cardiac catheterisation procedures and are exposed to considerable ionising radiation early in life. This study aimed to develop a method for estimating the dose area product () from paediatric cardiac catheterisation procedures (1975-1989) at a national centre for paediatric cardiology and to evaluate trends inand exposure parameters until 2021. Data from 2200 catheterisation procedures on 1685 patients (1975-1989) and 4184 procedures on 2139 patients (2000-2021) under 18 years of age were retrospectively collected.values were missing for 1975-1989 but available from 2000 onward. The missingwas estimated from air kerma and beam area, based on exposure records and input from clinicians working at that time.trends were analysed over time and age. There was a 71% reduction in medianfrom the period 1975-1989 (median 6.63 Gy cm) to 2011-2021 (1.91 Gy cm). Theincreases significantly (= 0.0001) with patient age, which was associated with body weight. Approximately 80% of the totalwas from cine acquisition in 1975-1989, while 20% was from fluoroscopy. Theestimate during 1975-1989 was considerably impacted by the assumptions of missing parameters such as tube filtration, focus-to-heart distance, beam area, and number of cine series. The decreasing trend invalues was attributed to advancements in both technologies and clinical practices. The high contribution of cine acquisition to the total dose during 1975-1989 was due to factors such as a high frame rate, multiple acquisitions, and high tube current. The estimatedvalues for the period 1975-1989 are of importance for the dose reconstruction and risk assessments in the EU epidemiology project Health Effects of Cardiac Fluoroscopy and Modern Radiotherapy in Pediatrics(HARMONIC).

Extremity radiation exposure in nuclear medicine is a growing concern because it may surpass the maximum permissible dose of 500 mSv. This study aimed to assess the occupational finger dose received by technologists during the preparation and administration ofF-FDG radiopharmaceuticals in positron emission tomography-computed tomography (PET-CT) whole-body scan procedures. Fifty scans were selected, with one procedure excluded due to a high administered activity. The mean administered activity per scan was 207.2 ± 41.8 MBq, with preparation and administration times averaging 1.44 ± 1.30 min and 0.46 ± 0.31 min, respectively. The technologist's mean total finger dose received during preparation and administration was 253.5 ± 153.3 Sv per procedure. A significant positive correlation was found between the administered activity and occupational dose, with patient's body mass index, preparation time, and administration time also contributing to dose variation. Based on 703 PET-CT procedures conducted in 2022, the estimated occupational finger dose for a technologist was 178.2 mSv annually. This value is well below the International Commission on Radiological Protection's maximum permissible dose of 500 mSv. The findings of this study have a significant impact on extremity dosimetry in nuclear medicine in Sri Lanka, as this is the first study of its kind.

With the continuous advancement and clinical application of CT technology, the increasing collective dose burden from CT scans and associated potential health risks have become significant concerns in radiation protection. Current research increasingly focuses on the cumulative effective dose (CED) resulting from multiple CT scans, often revealing patients with high CEDs, even exceeding 100 mSv. However, reports on CEDs from multiple CT scans in China are scarce. Therefore, we investigated the distribution of CT scan frequencies and CEDs at a comprehensive hospital in Shanghai, examining data from 1 October 2022, to 30 April 2024, sourced from the hospital's radiology information system. The effective dose () was estimated using conversion factorsand DLP values from Radiation Dose Structured Reports (RDSR). We assessed the number of CT examinations conducted per patient and evaluated the CED over 1.6 years. During this period, 112 339 CT examinations were performed. Significant differences in CT examination frequencies were observed across different age groups and examination regions (< 0.01). A total of 78.43% of patients underwent only one CT examination in 1.6 years, while 0.03% had more than 10 examinations, with a maximum of 15. Of the patients, 67.78% (76,142 individuals) received a CED less than 10 mSv, 0.05% (53 patients) received a CED over 50 mSv, and one patient exceeded 100 mSv. In conclusion, this study underscored the necessity of monitoring patients with high CT examination frequencies and CEDs, highlighting the importance of justification and optimization in medical radiation protection.

Electromagnetic compatibility testing plays an important role in the type testing of radiation protection dosemeters in view of technical developments and the associated increase in electromagnetic fields. Lately, the use of inductive charging devices has grown as a user-friendly type of charging mobile-phones. In this article, we investigate their impact on active personal dosemeters (APD). The measurements show a substantial additional dose reading of up to several tens of mSv when exposed to the field of an inductive charger for 20 s. According to the widely used Qi standard, the charging devices operate at frequencies of between 87 kHz and 205 kHz for power transfers between 5 W and 30 W. These parameters fall outside the scope of type-testing standards for APD. An update of the standards might therefore be necessary.

This study examines the effect of paediatric mesh-type reference computational phantoms on organvalues resulting from radioiodine (I) intake. Using Geant4, we estimatedIvalues for 30 radiosensitive target tissues due to emission from the thyroid (Target ← Thyroid) in these phantoms. Our results show thatvalues differ between male and female phantoms of the same age andvalues also decrease as phantom age increases. The male-to-femalevalue ratio typically varies within 10%, with larger differences observed for the esophagus, extra-thoracic regions, muscles, bladder, and sex organs. On average,values for mesh phantoms are approximately 17% higher than those for voxel phantoms, with larger discrepancies for organs remodelled separately in mesh phantoms. The study provides organvalues for the paediatric population due toI exposure from the thyroid, based on the reference mesh-type computational phantoms, enhancing organ dose estimation in emergency situations and during radioiodine treatment.

The information about the radiation risk of non-cancer respiratory diseases is inconsistent and mainly corresponds to mortality. Previously, an increased risk of chronic bronchitis incidence was demonstrated in the cohort of workers employed at the first Russian nuclear facility Mayak Production Association who had been chronically exposed to gamma rays (externally) and to alpha-active plutonium aerosols (internally). Within this retrospective study, we performed analyses of incidence of and mortality from chronic bronchitis and bronchial asthma using improved estimates of radiation doses provided by the "Mayak Worker Dosimetry System (MWDS) - 2013". The cohort included 22,377 individuals hired in 1948-1982, and its follow-up was extended by 10 years (to the end of 2018). The excess relative risk of chronic bronchitis incidence per unit radiation dose (ERR/Gy) and the 95% confidence interval (95% CI) were: with the 0-year lag ERR/Gy=0.07 (95% CI -0.01, 0.17) for gamma exposure and ERR/Gy=0.36 (95% CI 0.13, 0.68) for alpha exposure; with the 10-year lag ERR/Gy=0.15 (95% CI 0.04, 0.30) for gamma exposure and ERR/Gy=0.54 (95% CI 0.19, 1.03) for alpha exposure. The chronic bronchitis mortality risk was significantly associated with internal alpha exposure only for certain worker categories: ERR/Gy=4.08 (95% CI 0.59, 14.3) in males; ERR/Gy=7.10 (95% CI 0.31, 70.44) in former smokers; ERR/Gy=7.94 (95% CI 1.71, 30.2) in workers with the smoking index above 20 pack×years. No association was observed in the chronic bronchitis mortality risk with external gamma exposure. No strong evidence was observed for the impact of gamma and alpha exposure on risk of mortality from chronic bronchitis. The study confirmed the significant positive linear association of the chronic bronchitis incidence risk with gamma and alpha radiation doses from occupational chronic external and internal exposure. However, the estimates of ERR/Gy of alpha particles from internal exposure appeared to be almost 2.4-3 times lower than those based on the MWDS-2008. The observed inconsistency requires further clarification. As for bronchial asthma in Mayak workers, no association was demonstrated in the incidence and mortality risks with occupational gamma and alpha radiation exposure.

Radiology is now predominantly a digital medium and this has extended the flexibility, efficiency and application of medical imaging. Achieving the full benefit of digital radiology requires images to be of sufficient quality to make a reliable diagnosis for each patient, while minimising risks from radiation exposure, and so involves a careful balance between competing objectives. When an optimisation programme is undertaken, a knowledge of patient doses from surveys can be valuable in identifying areas needing attention. However, any dose reduction measures must not degrade image quality to the extent that it is inadequate for the clinical purpose. The move to digital imaging has enabled versatile image acquisition and presentation, including multi-modality display and quantitative assessment, with post-processing options that adjust for optimal viewing. This means that the appearance of an image is unlikely to give any indication when the dose is higher than necessary. Moreover, options to improve performance of imaging equipment add to its complexity, so operators require extensive training to be able to achieve this. Optimisation is a continuous rather than single stage process that requires regular monitoring, review, and analysis of performance feeding into improvement and development of imaging protocols. The ICRP is in the process of publishing two reports about optimisation in digital radiology. The first report sets out components needed to ensure that a radiology service can carry optimisation through. It describes how imaging professionals should work together as a team and explains the benefits of having appropriate methodologies to monitor performance, together with the knowledge and expertise required to use them effectively. It emphasises the need for development of organisational processes that ensure tasks are carried out. The second ICRP report deals with practical requirements for optimisation of different digital radiology modalities, and builds on information provided in earlier modality specific ICRP publications.