ICRP Publication 146: Radiological Protection of People and the Environment in the Event of a Large Nuclear Accident : Update of ICRP PUBLICATIONS 109 AND 111

The system of radiological protection and the UN sustainable development goals

In 2015 the United Nations issued 17 Sustainable Development Goals (SDGs) addressing a wide range of global social, economic, and environmental challenges. The main goal of this paper is to provide an understanding of how the current System of Radiological Protection relates to these SDGs. In the first part it is proposed that the current System of Radiological Protection is implicitly linked to sustainable development. This is substantiated by analysing the features of the current System as set out by the International Commission on Radiological Protection (ICRP) in its publications. In the second part it is proposed that sustainability should be considered and more explicitly addressed in the next ICRP general recommendations, as part of the currently ongoing review and revision of the current System. A few examples are given of how this could be realised, and it is proposed that this issue should be discussed and developed together with the international community interested in radiological protection.

Overt Scientific Bias and Clandestine Acts by Trusted Scientists: The Flawed Application of the Linear No-threshold Model

ABSTRACT

The Health Physics Society (HPS) released a video documentary on the history of the linear no-threshold (LNT) model in April 2022. It exposed many scientific and ethical failings of many leaders, influential scientists, and organizations that have resulted in the current system of radiological protection. Since then, the society received many comments; most were supportive, while a few criticized the video documentary as delivering an anti-LNT message. Shortly thereafter, many emails discovered via an independent Freedom of Information Act request revealed multiple layers of coordination between prominent people in the field of radiation protection to coopt the leadership within the HPS and suppress information they perceived or assumed to be contrary to a pro-LNT message. Many of these emails were published by JunkScience.com, an independent organization that exposes faulty scientific data and analyses used to advance special interests and hidden agendas. This Forum article is intended to document in the peer-reviewed literature the JunkScience.com findings of clandestine acts by trusted scientists within the radiation protection community. The emails exposed strong personal biases, actions taken by leaders within the National Commission on Radiation Protection and Measurements (NCRP) to "save the Society" from its "downward spiral," and actions taken by NCRP and HPS members serving on a National Academies of Sciences committee to suppress scientific information relevant to the debate about health effects in low-dose environments. These anti-science actions harm our entire profession and the trust that Congress bestows on our scientific organizations expecting to receive objective recommendations based on sound science. It is important that these events are recorded in the scientific literature from a historical perspective. The radiation protection community will be judged not by what is revealed in this article but by what actions are taken from here.

Intra-mediary expertise: Trans-science and expert understanding of the public

What is the role of experts and their expertise in the context of trans-science, in which issues that are raised in scientific terms cannot be answered by science alone? This article examines the discourses and practices around safety of low-dose exposure to radiation in the ongoing aftermath of the Fukushima Daiichi Nuclear Power Plant accident in Japan in 2011. Following the nuclear fallout, scientific experts and STS scholars in Japan debated what forms of science communication were adequate to address the situation. Ethnographic research and textual analysis of their debates show a shift in emphasis on the role of experts from cultivating 'public understanding of science' for the sake of science and policy to an 'expert understanding of the public' for the sake of the public and its diverse everyday concerns. Two forms of expertise are emerging: 'co-expertise' and 'intra-mediary expertise'. Both are parts of a transition from a paternalistic form of expertise to one that acknowledges the need to engage the public to address issues of scientific uncertainty. However, co-expertise ultimately upholds the existing political structures that shape risk governance, while intra-mediary expertise engages those often excluded from current structures of accountability. Discussion of the potentials and limitations of emerging forms of expertise in Japan show that epistemic justice is not enough. Civic justice that acknowledges diverse publics and their needs must be upheld in the uncertain sphere between science, politics, and everyday life.

Review of ethical values across the ICRP's system of radiological protection

In 2018, the International Commission on Radiological Protection (ICRP) released Publication 138, which highlights the ethical values foundational to the system of radiological protection. Additional work, both within and beyond the ICRP, has proposed or recommended ethical values associated with applications of the system in different areas, perhaps most notably in medical, veterinary, and environmental radiological protection. There are also existing ethical frameworks not specifically related to radiological protection that are nonetheless relevant to its practice; for example, the Beauchamp and Childress principles of biomedical ethics are of particular significance when it comes to medical uses of radiation and radioactivity. At first glance, it may seem as if there are unique or isolated sets of ethical values that need to be applied depending on the circumstance. Yet while each area of application will indeed have its own unique aspects and associated value judgements, there are consistent and complementary relationships between these ethical values. This paper reviews the work of the ICRP related to ethics, including brief historical context, and highlights the similarities and differences between sets of ethical values with emphasis on medical, veterinary, and environmental applications of radiological protection.

Evaluating the Radioactive Waste Produced per Patient by Radiopharmaceutical Sources and Measuring the Radioactive Contamination of Surfaces and Staff at the Bushehr Nuclear Medicine Department

Background

Nuclear medicine is an integral and developing field in diagnosing and treating diseases. Monitoring individuals' protection and radiation contamination in the workplace is vital for preserving working environments.

Objective

This study aimed to monitor the nuclear medicine department's personnel, environment, and wastes to determine the level of occupational radiation and environmental pollution in Bushehr's nuclear medicine department.

Material and Methods

In this cross-sectional study, the initial activity of each radioisotope, radiopharmaceutical, and radioactive waste was measured using a "well counter" daily for three months. Three irradiators' absorbed doses were measured using a direct reading dosimeter. The contamination was determined using an indirect wipe test method on various surfaces. A Geiger Müller dosimeter was employed to examine personnel's hands, clothing, and footwear.

Results

The highest activity was observed in technetium waste (1118.31 mCi). Every irradiator received a lower absorption dose than the International Commission on Radiological Protection (ICRP) standard threshold. The majority of contamination was associated with the exercise test room (0.04 Bq/cm2) and its work surface (0.013 Bq/cm2), which were both below the threshold (0.5 Bq/cm2). Staff monitoring indicated that two nurses (10 and 11 individuals) had the highest contamination rate (23.7%).

Conclusion

Daily assessment of the type, activity, and method of radiopharmaceutical administration to the patient is advantageous for waste management. Surface contamination monitoring can significantly contribute to the estimation of the level of radiation pollution in the environment.

Validating a Four-gene Set for H-ARS Severity Prediction in Peripheral Blood Samples of Irradiated Rhesus Macaques

Increased radiological and nuclear threats require preparedness. Our earlier work identified a set of four genes (DDB2, FDXR, POU2AF1 and WNT3), which predicts severity of the hematological acute radiation syndrome (H-ARS) within the first three days postirradiation In this study of 41 Rhesus macaques (Macaca mulatta, 27 males, 14 females) irradiated with 5.8-7.2 Gy (LD29-50/60), including some treated with gamma-tocotrienol (GT3, a radiation countermeasure) we independently validated these genes as predictors in both sexes and examined them after three days. At the Armed Forces Radiobiology Research Institute/Uniformed Services University of the Health Sciences, peripheral whole blood (1 ml) of Rhesus macaques was collected into PAXgene® Blood RNA tubes pre-irradiation after 1, 2, 3, 35 and 60 days postirradiation, stored at -80°C for internal experimental analyses. Leftover tubes from these already ongoing studies were kindly provided to Bundeswehr Institute of Radiobiology. RNA was isolated (QIAsymphony), converted into cDNA, and for further gene expression (GE) studies quantitative RT-PCR was performed. Differential gene expression (DGE) was measured relative to the pre-irradiation Rhesus macaques samples. Within the first three days postirradiation, we found similar results to human data: 1. FDXR and DDB2 were up-regulated, FDXR up to 3.5-fold, and DDB2 up to 13.5-fold in the median; 2. POU2AF1 appeared down regulated around tenfold in nearly all Rhesus macaques; 3. Contrary to human data, DDB2 was more up-regulated than FDXR, and the difference of the fold change (FC) ranged between 2.4 and 10, while the median fold changes of WNT3, except days 1 and 35, were close to 1. Nevertheless, 46% of the Rhesus macaques showed down-regulated WNT3 on day one postirradiation, which decreased to 12.2% on day 3 postirradiation. Considering the extended phase, there was a trend towards decreased fold changes at day 35, with median-fold changes ranging from 0.7 for DDB2 to 0.1 for POU2AF1, and on day 60 postirradiation, DGE in surviving animals was close to pre-exposure values for all four genes. In conclusion, the diagnostic significance for radiation-induced H-ARS severity prediction of FDXR, DDB2, and POU2AF1 was confirmed in this Rhesus macaques model. However, DDB2 showed higher GE values than FDXR. As shown in previous studies, the diagnostic significance of WNT3 could not be reproduced in Rhesus macaques; this could be due to the choice of animal model and methodological challenges.

Continuing Steady Challenges Involved in the Lifting of Evacuation Orders after the Fukushima Daiichi Nuclear Power Plant Accident

ABSTRACT

Steady efforts for recovery and reconstruction after the accident at the Fukushima Daiichi Nuclear Power Plant have been underway for 12.5 y. The present study reports on the world's first-ever efforts for a gradual and safe return to areas contaminated with radiation fallout and reconstruction support by providing an overview of the actual situation regarding the strategy for return, especially with the transition after the lifting of the evacuation order by the Japanese government. A stage-by-stage progression of the evacuation order and lifting strategy is summarized chronologically in the following three phases: the Emergency Phase in 2011, the Reconstruction Phase from 2013 to 2020, and the Challenging Phase for Lifting All the Evacuation Zones from 2023. Through the lifting strategy of the government, the number of evacuees decreased significantly, especially during the Reconstruction Phase, from 152,113 in May 2013 to 37,826 in May 2020. It is crucial to strengthen support for reconstruction and convey an unbiased and accurate understanding of Fukushima Prefecture by developing a concrete strategy for community development and increasing the size of the exchange population.

Low-Cost Sensor Deployment on a Public Minibus in Fukushima Prefecture

This study analyzed radiation dose data to observe the annual decline in ambient radiation doses and assess the factors contributing to fluctuations in reconstructed areas of the Fukushima prefecture. Utilizing a novel mobile monitoring system installed on a community minibus, the study employed a cost-effective sensor, namely, Pocket Geiger which was integrated with a microcontroller and telecommunication system for data transfer, access, visualization, and accumulation. The study area included the region between Okuma and Tomioka towns. The ambient dose rate recorded along the minibus route was depicted on a map, averaged within a 1 × 1 km mesh created with the Quantum Geographic Information System. To ensure accuracy, the shielding factor of the minibus material is determined to adjust the dose readings. A significant decrease (p < 0.001) in the radiation dose ranges from 2022 to 2023 was observed. The land use classification by the Advanced Land Observation Satellite revealed an ecological half-life ranging from 2.41 years to 1 year, suggesting a rapid radiation decay across all land types. This underscores the close connection between radiation attenuation and environmental factors, as well as decontamination efforts across diverse land categories.

Exploring the role of large language models in radiation emergency response

In recent times, the field of artificial intelligence (AI) has been transformed by the introduction of large language models (LLMs). These models, popularized by OpenAI's GPT-3, have demonstrated the emergent capabilities of AI in comprehending and producing text resembling human language, which has helped them transform several industries. But its role has yet to be explored in the nuclear industry, specifically in managing radiation emergencies. The present work explores LLMs' contextual awareness, natural language interaction, and their capacity to comprehend diverse queries in a radiation emergency response setting. In this study we identify different user types and their specific LLM use-cases in radiation emergencies. Their possible interactions with ChatGPT, a popular LLM, has also been simulated and preliminary results are presented. Drawing on the insights gained from this exercise and to address concerns of reliability and misinformation, this study advocates for expert guided and domain-specific LLMs trained on radiation safety protocols and historical data. This study aims to guide radiation emergency management practitioners and decision-makers in effectively incorporating LLMs into their decision support framework.

Ethical and societal aspects of radiological protection for offspring and next generations

PURPOSE

Over the last decade or so, ethical and societal aspects of radiological protection have received increasing attention. This is also reflected in the publications of the International Commission on Radiological Protection (ICRP). The current paper aims at identifying relevant ethical and societal topics which should receive attention in the context of radiological protection for offspring and next generations.

MATERIALS AND METHODS

We present a non-comprehensive review of the subject, based on presentation made at an ICRP workshop in Budapest in 2022. We first discuss the ethical values promoted by ICRP, and the application of these values in cases of (potential) pre-conceptual and prenatal radiation exposures. We then consider experience gained after the Fukushima accident indicating particular societal concerns about the health effects of such exposures.

RESULTS AND CONCLUSIONS

Beneficence/non-maleficence, prudence, justice and dignity, the "core values" of the system of radiological protection have special roles to play when heritable and/or in utero effects are to be considered. Prudence, in particular, must be taken account of in view of the fact that solid scientific data in humans are largely lacking in this area, and it is necessary to rely on insights from animal experiments as well as theoretical considerations. As regards societal considerations, the perception of risk among (potentially) affected populations needs to be taken seriously. Accountability, transparency, and inclusivity, the "procedural values" promoted by ICRP for the practical implementation of the system of radiological protection play a central role in overcoming skepticism and creating trust. Stakeholder involvement should emphasize cooperation and dialogue, which allows for the joint evaluation of an exposure situation by experts and affected people.

Factors influencing acceptability of final disposal of incinerated ash and decontaminated soil from TEPCO's Fukushima Daiichi nuclear power plant accident

TEPCO's Fukushima Daiichi nuclear power plant accident prompted extensive decontamination work. The decontaminated soil and incinerated ash generated by the process are scheduled for final disposal by March 2045 outside Fukushima Prefecture. The final disposal is unprecedented worldwide. Clarifying their acceptability will contribute to the final disposal of decontaminated soil and incinerated ash, as well as add knowledge about the perceived risk of low-concentration radioactive waste. A questionnaire survey was conducted to assess the psychological factors influencing final disposal acceptability. The results of the structural equation modeling demonstrated stable results, with risk perception decreasing acceptability, social benefits increasing acceptability, and personal benefits having limited impact. The initiative for the final disposal of decontaminated soil and incinerated ash can facilitate the reconstruction of Fukushima Prefecture after the disaster. Trust and intergenerational expectations are critical factors influencing the acceptability of this disposal. The responses were classified based on the relevance of moral norms using cluster analysis and moral foundations. The influence of each element on acceptability varied depending on the cluster. Trust was identified as the most influential factor in acceptability, regardless of the level of importance placed on moral norms.

Impacts of environmental decontamination on the rebuilding of returnees' lives after the Fukushima accident

Environmental decontamination after a nuclear disaster not only contributes to reducing the public's exposure to radiation, it also introduces waste disposal issues arising from the decontamination process. In addition to that issue, the optimisation of decontamination efforts necessitates the consideration of various environmental, economic, and societal factors. Stakeholders' perspectives are important for identifying the multifaceted aspects to be considered. We conducted a semi-structured interview survey in 2019 with ten residents in a rural community in Fukushima, Japan, which experienced a six-year-long evacuation due to the 2011 Fukushima Daiichi Nuclear Power Plant accident. The main survey questions addressed returnees' perceptions of the decontamination of farmlands and forests. The 'Steps for Coding and Theorization' procedure was used for qualitative analysis. The analysis illuminated the positive and negative impacts of the decontamination process on the rebuilding of the returnees' rural lives from various perspectives and identified elements to be considered for the optimisation of future remediation efforts. The removal of radioactive materials had a positive psychological impact on the returnees, fostering a sense of security that their crops were safe and instilling confidence that the high-quality environment of the region had been restored. These aspects were not included among the initial governmental objectives for decontamination, which were aimed solely at reducing radiation exposure. By contrast, the removal of fertile topsoil from farmland had a negative impact on the residents, making them hesitant to resume farming. Our findings suggest that emphasising procedural fairness in decision-making of decontamination options such as reflection of stakeholders' opinions led to residents perceiving their post-decontamination situation more positively. Our results provide valuable insights for optimising remediation strategies for the recovery process following a significant nuclear accident.

The three R's of reasonable in radiological protection: relationships, rationale, and resources

Central to applying the principle of optimisation in the system of radiological protection is the evaluation of what level of radiation exposure should be considered 'as low as reasonably achievable' (ALARA), after taking into account the prevailing circumstances. Determining what is 'reasonable' is an abstract, although somewhat intuitive concept with many potential interpretations depending on both the situation and those involved, whether individuals or organisations. There are common themes in the types of considerations that need to be addressed to determine 'reasonableness' regardless of the exposure situation. However, despite the consistent and agreeable nature of these themes, there remains a gap in how to apply them in real situations. For example, without measurable goalposts (or a clear process for setting such goalposts) for determining what constitutes ALARA, we can find ourselves misinterpreting the optimisation process as keeping exposures 'as low as possible'. We propose herein, by consolidating and building on existing ideas, an easily understandable and actionable 'reasonableness' framework. This simple, yet broadly applicable tool is intended to help radiation protection experts in the systematic, deliberative, and collaborative reflection on all of the factors that make up 'reasonable' before making a decision-whether it be a proposed medical treatment or clean-up of a contaminated site. Each process execution and decision itself will necessarily retain the complexity of the prevailing circumstance. The proposed 'Rs' of Reasonable represent Relationships (stakeholders, empathy, and trust), Rationale (contextual, technical, and ethical), and Resources (technological, financial, and time).

Tailoring Digital Tools to Address the Radiation and Health Information Needs of Returnees after a Nuclear Accident

Digital tools are increasingly used for health promotion, but their utility during recovery from a nuclear disaster has yet to be established. This study analysed differences in knowledge, attitude, and practice (KAP) toward digital tools for radiation protection and health promotion, and preferences for specific application functions, among cohorts living within and outside areas affected by the Fukushima Daiichi nuclear power station (FDNPS) accident. A needs assessment was conducted by internet survey, and responses from those affected (N = 86) and not affected (N = 253) were compared and quantified by an adjusted odds ratio (aOR), using logistic regression analyses. KAP toward the radiation-related application in the affected group had an aOR of 1.95 (95% confidence interval (CI) = 1.12–3.38) for knowledge, and 5.71 (CI = 2.55–12.8) for practice. Conversely, toward the health-related application, the aOR of the affected group was 0.50 (CI = 0.29–0.86). The preference in the affected group was significantly lower for two application functions related to radiation measurement and two health-related functions (one about the effects of radiation in general and another about personal health advice in general): aOR range 0.43–0.50. Development of specific applications incorporating the findings from this survey was intended to foster a locally appropriate eHealth environment during recovery from the FDNPS accident.

Rahim MH, Nordin R, Mohamed F, Abu-Samah A, Abdullah NF. Ionizing Radiation Monitoring Technology at the Verge of Internet of Things

As nuclear technology evolves, and continues to be used in various fields since its discovery less than a century ago, radiation safety has become a major concern to humans and the environment. Radiation monitoring plays a significant role in preventive radiological nuclear detection in nuclear facilities, hospitals, or in any activities associated with radioactive materials by acting as a tool to measure the risk of being exposed to radiation while reaping its benefit. Apart from in occupational settings, radiation monitoring is required in emergency responses to radiation incidents as well as outdoor radiation zones. Several radiation sensors have been developed, ranging from as simple as a Geiger-Muller counter to bulkier radiation systems such as the High Purity Germanium detector, with different functionality for use in different settings, but the inability to provide real-time data makes radiation monitoring activities less effective. The deployment of manned vehicles equipped with these radiation sensors reduces the scope of radiation monitoring operations significantly, but the safety of radiation monitoring operators is still compromised. Recently, the Internet of Things (IoT) technology has been introduced to the world and offered solutions to these limitations. This review elucidates a systematic understanding of the fundamental usage of the Internet of Drones for radiation monitoring purposes. The extension of essential functional blocks in IoT can be expanded across radiation monitoring industries, presenting several emerging research opportunities and challenges. This article offers a comprehensive review of the evolutionary application of IoT technology in nuclear and radiation monitoring. Finally, the security of the nuclear industry is discussed.

Areas of research to support the system of radiological protection

This document presents the ICRP's updated vision on "Areas of Research to Support the System of Radiological Protection", which have been previously published in 2017. It aims to complement the research priorities promoted by other relevant international organisations, with the specificity of placing them in the perspective of the evolution of the System of Radiological Protection. This document contributes to the process launched by ICRP to review and revise the System of Radiological Protection that will update the 2007 General Recommendations in ICRP Publication 103.

From a policy perspective: what is at stake?

This paper does not necessarily reflect the views of the International Commission on Radiological Protection.What is at stake? It was one of the most frequently asked questions in a series of fora with concerned parties on the rehabilitation of living conditions in the aftermath of the accident at Fukushima Daiichi nuclear power plant. It was obvious that radioactive contamination was the source of the problem, and people were at a loss over how to cope with the situation. Various measures were taken under such circumstances, including detailed radiation monitoring, a decontamination programme to reduce the level of radiation in the living environment, and activities related to communication about radiation risk. Nevertheless, this question was asked repeatedly. Measures against radiation exposure were certainly necessary, but it is a reality that they were not enough to solve the difficulties experienced by people in the affected areas. This article presents the author's personal view of the underlying reasons for this, and discusses the way to facilitate recovery after a nuclear accident.

The role of experts in the development of recovery handbooks: UK and European experience

The importance of involving experts in the development of strategies for managing areas contaminated as a result of a nuclear accident is now well recognised. Following the Chernobyl accident in 1986, the initial focus, quite understandably, was on the technical aspects of reducing doses to the affected population. Subsequently, work carried out in the UK and elsewhere in Europe looked at the broader impacts of protective actions on agriculture, the environment, and society. From 1997, a group of experts from academia, government, and non-government organisations met regularly in the UK to debate these issues. One of the outputs included the first version of the UK Recovery Handbook for Radiation Incidents in 2005. Based on the success of the UK group, a European network of experts was established, leading to the development of European handbooks in 2009. The UK handbooks are living documents that are updated regularly with substantive input from experts.

Supporting societal and economic dynamics of recovery: lessons from Chernobyl and Fukushima

This paper does not necessarily reflect the views of the International Commission on Radiological Protection.Beyond the consideration of radiological aspects, the rehabilitation of living and working conditions after a large nuclear accident is a complex process in which all dimensions of individual and community life are involved and interconnected. Responsibles of socio-economic entities are facing various difficulties/challenges, including the implementation of protective actions for ensuring the protection of employees, the continuity of production of good-quality products in affected areas, and restoring the confidence of consumers. For affected local communities, the deployment of a socio-economic programme is essential to enable a sustainable future while recognising that a return to the pre-accident situation is generally not achievable. In this context, supporting the societal and economic dynamics of the recovery process requires the adoption of specific governance mechanisms respecting a series of ethical and social values, as highlighted by lessons from the post-accident management of the Chernobyl and Fukshima accidents at Chernobyl and Fukushima Daiichi nuclear power plants.

Development of an application tool to support returnees in Fukushima

To promote radiation protection and health promotion among returning residents (returnees) in coastal areas of Fukushima, eHealth principles were used to develop a new application tool (app) that can record radiation exposure and health status while providing comprehensive support to returnees. Intended users are returnees and health and welfare workers. After assessing their needs, a flowchart and prototype for operational logic were created using commercially available software tools. Professional developers will focus on improving the user interface and ensuring data security. The finished app will be compatible with mobile telephones and tablets. Utility and ease of use are paramount to serve returnees of all ages effectively.

YouTube Videos Related to the Fukushima Nuclear Disaster: Content Analysis

Background

YouTube (Alphabet Incorporated) has become the most popular video-sharing platform in the world. The Fukushima Daiichi Nuclear Power Plant (FDNPP) disaster resulted in public anxiety toward nuclear power and radiation worldwide. YouTube is an important source of information about the FDNPP disaster for the world.

Objective

This study's objectives were to examine the characteristics of YouTube videos related to the FDNPP disaster, analyze the content and comments of videos with a quantitative method, and determine which features contribute to making a video popular with audiences. This study is the first to examine FDNPP disaster–related videos on YouTube.

Methods

We searched for the term “Fukushima nuclear disaster” on YouTube on November 2, 2019. The first 60 eligible videos in the relevance, upload date, view count, and rating categories were recorded. Videos that were irrelevant, were non-English, had inappropriate words, were machine synthesized, and were <3 minutes long were excluded. In total, 111 videos met the inclusion criteria. Parameters of the videos, including the number of subscribers, length, the number of days since the video was uploaded, region, video popularity (views, views/day, likes, likes/day, dislikes, dislikes/day, comments, comments/day), the tone of the videos, the top ten comments, affiliation, whether Japanese people participated in the video, whether the video recorder visited Fukushima, whether the video contained theoretical knowledge, and whether the video contained information about the recent situation in Fukushima, were recorded. By using criteria for content and technical design, two evaluators scored videos and grouped them into the useful (score: 11-14), slightly useful (score: 6-10), and useless (score: 0-5) video categories.

Results

Of the 111 videos, 43 (38.7%) videos were useful, 43 (38.7%) were slightly useful, and 25 (22.5%) were useless. Useful videos had good visual and aural effects, provided vivid information on the Fukushima disaster, and had a mean score of 12 (SD 0.9). Useful videos had more views per day (P<.001), likes per day (P<.001), and comments per day (P=.02) than useless and slightly useful videos. The popularity of videos had a significant correlation with clear sounds (likes/day: P=.001; comments/day: P=.02), vivid information (likes/day: P<.001; comments/day: P=.007), understanding content (likes/day: P=.001; comments/day: P=.04). There was no significant difference in likes per day (P=.72) and comments per day (P=.11) between negative and neutral- and mixed-tone videos. Videos about the recent situation in Fukushima had more likes and comments per day. Video recorders who personally visited Fukushima Prefecture had more subscribers and received more views and likes.

Conclusions

The possible features that made videos popular to the public included video quality, videos made in Fukushima, and information on the recent situation in Fukushima. During risk communication on new forms of media, health institutes should increase publicity and be more approachable to resonate with international audiences.

ICRP recommendations for recovery

In 2020, the International Commission on Radiological Protection (ICRP) issued Publication 146 which provides a framework of the radiological protection of people and the environment in the case of a large nuclear accident. Mitigation of radiological consequences is achieved using the fundamental principles of justification of decisions and optimisation of protection. These recommendations emphasise the importance of the optimisation of protection for the rehabilitation of living and working conditions in the affected areas during the intermediate and long-term phases. They underline the role of co-operation between the authorities, experts, and the affected population in the co-expertise process to facilitate informed decisions about their own protection. ICRP defines reference levels to be selected within generic bands of exposure considering the induced risk of radiation, as well as the feasibility of controlling the situation.