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.

Comparison between external and internal doses to the thyroid after the Fukushima Daiichi Nuclear Power Plant accident.

To analyze the association between radiation dose and thyroid cancer after the 2011 Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, external doses have often been used because of the difficulty to estimate internal thyroid doses individually due to the lack of human data. However, no evaluation has been made as to whether external dose is a good surrogate marker for internal thyroid dose individually. This study aimed at analyzing the relationship between external doses and internal thyroid doses estimated by recently developed methodology. For four municipalities affected by the accident, 200 individuals aged under 20 at the time of the accident per municipality were randomly selected, and their external and internal thyroid doses and their ratios were estimated individually. In a separate analysis, median and arithmetic mean values for external thyroid doses estimated for persons of 16 municipalities that included the above four were compared with those for previously estimated internal thyroid doses. The ratios of the median of internal thyroid dose to that of external thyroid dose in these 16 municipalities ranged from 0.56 to 13.8 for 15-year-old children and 0.91 to 21.1 for 1-year-old children. No consistent relationship between external and internal thyroid doses was found in all 16 municipalities. Thus, thyroid doses from both external and internal exposures should be used to analyze the association between radiation dose and thyroid cancer detection rates for persons who lived in Fukushima Prefecture at the time of the FDNPP accident. (240).

Estimation of children's thyroid equivalent doses in 16 municipalities after the Fukushima Daiichi Nuclear Power Station accident.

To elucidate the association between radiation dose and thyroid cancer after the 2011 Fukushima Daiichi Nuclear Power Station (FDNPS) accident, it is essential to estimate individual thyroid equivalent doses (TEDs) to children. In a previous study, we reported a methodology for reconstructing TEDs from inhalation. That methodology was based on individual behavioral survey sheets of the Fukushima Health Management Survey (FHMS) combined with a spatiotemporal radionuclides database constructed by an atmospheric transport, diffusion, and deposition model (ATDM)-the Worldwide version of System for Prediction of Environmental Emergency Dose Information (WSPEEDI) in seven municipalities. In the present study, we further refined our methodology and estimated the combined TEDs from inhalation and ingestion among children in 16 municipalities around the nuclear power station utilizing 3256 individual whereabouts questionnaire survey sheets. Distributions of estimated TEDs were similar to estimates based on direct thyroid measurements in 1080 children in Iwaki City, Kawamata Town, Iitate Village, and Minamisoma City. Mean TEDs in 1-year-old children ranged from 1.3 mSv in Date City to 14.9 mSv in Odaka Ward in Minamisoma City, and the 95th percentiles varied from 2.3 mSv in Date City to 28.8 mSv in Namie Town. In the future, this methodology can be useful for the epidemiological studies of thyroid cancer after the FDNPS accident.

Objective stress values during radiation emergency medicine for future human resources: Findings from a survey of nurses.

INTRODUCTION: Shortages of human resources in radiation emergency medicine (REM) caused by the anxiety and stress of due to working in REM, are a major concern. The present study aimed to quantify stress and identify which tasks involved in REM response are most stressful to help educate (human resource development) and effectively reduce stress in workers. Furthermore, the final goal was to reduce the anxiety and stress of medical personnel in the future, which will lead to sufficient human resources in the field of REM. METHODS: In total, 74 nurses who attended an REM seminar were asked to answer a questionnaire (subjective) survey and wear a shirt-type electrocardiogram (objective survey). Then, informed consent was obtained from 39 patients included in the analysis. In the objective survey, average stress values of participants for each activity during the seminar were calculated based on heart rate variability (HRV). The average stress value was output as stress on a relative scale of 0-100, based on the model which is the percentile of the low-frequency/high-frequency ratio derived from HRV at any point in time obtained over time. RESULTS: A total of 35 (89.7%) participants answered that they had little or no knowledge of nuclear disaster and 33 (84.6%) had more than moderate anxiety. Stress values observed during the decontamination process were significantly higher than those observed when wearing and removing protective gear and during the general medical treatment process (P = 0.001, 0.004, and 0.023, respectively). Stress values did not increase during general medical treatment performed in protective clothing, but increased during the decontamination process, which is the task characteristic of REM. DISCUSSION: Stress felt by medical personnel throughout the entire REM response may be effectively reduced by providing careful education/training to reduce stress during the decontamination process. Reducing stress during REM response effectively could contribute to resolving the shortage of human resources in this field.

[Recommendations for Optimising a Human Resource Development Training Programme for a Nuclear Accident Based on the Personal Backgrounds of Radiological Technologists: Experiences from the Fukushima Daiichi Nuclear Power Station Accident].

PURPOSE: The aim of this study was to provide the information needed to optimise a nuclear accident to human resource development training programmes for radiological technologists (RTs) based on the experience of the Fukushima Daiichi nuclear power station (FDNPS) accident. METHODS: A total of 330 respondents (availability rate: 56.5%) were obtained through a postal questionnaire survey of RTs in Fukushima Prefecture. The analysed items were the relationship between the individual attributes, subject's experience in responding to the FDNPS accident, and subject's records of participating in nuclear accident trainings before the FDNPS accident with regard to 1) "skills that need to be learnt (4 items)" and 2) "basic knowledge (4 items)" to respond to a nuclear accident. RESULTS: Regarding 1), air ambient dose and body surface contamination measurements were significantly associated with the number of beds at a place of work at the time of the FDNPS accident. In addition, consultations on radiation exposure were significantly associated with the experience in responding to the FDNPS accident and the records of participating in nuclear accident trainings before the FDNPS accident. Regarding 2), knowledge of internal exposure was significantly related to the years of employment at the time of the FDNPS accident and the experience in responding to the FDNPS accident. CONCLUSION: By considering the results of this study, it should be possible to provide training programmes for a nuclear accident that are optimally tailored to the background of the RTs.

Disaster response among hospital nurses dispatched to evacuation centers after the Great East Japan Earthquake: a thematic analysis.

BACKGROUND: Disaster relief operations involve a variety of components of healthcare efforts. The post-disaster recovery is a key component of hospital preparedness. This study aimed to investigate the role of hospital nurses in the disaster area and their challenges during the relief efforts after the Great East Japan Earthquake in 2011. METHODS: Semi-structured interviews were conducted with ten nurses who worked in a general public hospital before the Great East Japan Earthquake and were dispatched to the evacuation centers after the disaster. A qualitative approach with the thematic analysis method was employed. Three research queries (RQs) were prepared before the interview. RESULTS: The study participants played administrative roles as city employees in addition to performing nursing services as healthcare providers in evacuation centers. The first RQ on their challenges in evacuation centers gave us four themes: criticism by the evacuees, conflicts between multiple roles, difficulties in performing the first experience, and anxiety in working. The second RQ asking about motivation to accomplish disaster relief efforts raised three themes of carrying out the nursing role, acceptance by evacuees, and strengths of human connections. Two themes of awareness of disaster medicine and professional growth were raised from the third RQ of gains from the experiences in the evacuation centers. CONCLUSIONS: The hospital nurses in the disaster area performed multiple roles in the relief efforts in the evacuation centers, which developed a psychological burden on them. A sense of competence supported the motivation to accomplish the disaster relief activities and professional growth as a specialist in disaster medicine. A study limitation is missing hospital nurses who resigned during the relief efforts. Further study is warranted to refine the disaster preparedness of hospital operations.

Current situation survey for establishing personally acceptable radiation dose limits for nuclear disaster responders.

When responding to disasters, emergency preparedness is essential to ensure that disaster activities are performed smoothly, safely and efficiently. Investigations on the Fukushima accident revealed that lack of preparedness, poor communication and unsuitable emergency measures contributed to an inadequate emergency response to the nuclear disaster. In this study, we conducted a questionnaire survey on the establishment of a personal radiation exposure dose among Disaster Medical Assistance Team (DMAT) members in Japan who might be involved in the initial response to a nuclear disaster. Establishing personal exposure doses for personnel can encourage emergency preparedness and inform decisions on appropriate role assignments during nuclear response activities. Valid responses were obtained from 178 participants, and the response distribution was as follows: 'Already have own acceptable dose standard,' 16 (9%); 'Follow own institution's standard (and know its value),' 30 (17%); 'Follow own institution's standard (but do not know its value),' 59 (33%); 'Haven't decided,' 63 (35%) and 'Don't understand question meaning,' 10 (6%). We also assessed intention to engage in nuclear disaster activities among respondents via engagement intent scores (EIS) and found that participants who had established personal exposure standards had significantly higher EIS scores than those who had not decided or who did not understand the question. Thus, educating potential nuclear disaster responders on personal exposure doses may contribute to a higher intention to engage in emergency responses and improve preparedness and response efficiency.

Radiation Emergency Medical Preparedness in Japan: A Survey of Nuclear Emergency Core Hospitals.

OBJECTIVE: Based on experiences following the Great East Japan Earthquake and nuclear power plant accident in 2011, Nuclear Emergency Core Hospitals (NECHs) were designated as centers for radiation disaster management in Japan. This study aimed to investigate their current status and identify areas for improvement. METHODS: This cross-sectional study was conducted in October 2018. Demographic data were collected by a questionnaire with free text responses about attitudes toward NECHs. Considerations regarding risk communications during a radiation disaster were analyzed using qualitative text mining analysis. RESULTS: A total of 36 hospitals participated in this study. Only 31% of NECHs anticipated a radiation disaster. The importance of business continuity plans and risk communications was shown. Text analysis identified 7 important categories for health care workers during a radiation disaster, including media response, communications to hospital staff, risk communications, radiation effects on children, planning for a radiation disaster in the region, rumors, and the role in the region. CONCLUSION: The radiation disaster medical system and NECHs in Japan were surveyed. The importance of risk communications, planning for a radiation disaster in each region, and the role in the region are identified as issues that need to be addressed.

Contribution of radiation education to anxiety reduction among Fukushima Daiichi Nuclear Power Plant workers: a cross sectional study using a text mining method.

The purpose of this study is to investigate the frequency of education, knowledge of radiation and workplace anxiety of Fukushima Daiichi Nuclear Power Plant (FDNPP) workers and to analyze what type of words are used for anxiety with a text mining method. An original questionnaire survey was given to FDNPP workers, and a text mining method was used to extract information from free-entry fields. The questionnaires were collected from 1135 workers (response rate: 70.8%). It was found that when workers receive education on radiation, the increased knowledge helps to reduce their anxiety. Among the 1135 workers, 92 of 127 completed the free-entry field with valid entries. Seventy-one words were extracted by the text mining method. The words used differed depending on the degree of anxiety. The text mining method revealed information about the presence or absence of radiation anxiety and the subjects' working environment and background.

Increasing Disaster Medical Assistance Teams' Intent to Engage with Specific Hazards.

To ensure human resource availability for a smooth response during various types of disasters, there is a need to improve the intent of those involved in responding to each hazard type. However, Disaster Medical Assistance Team personnel's intent to engage with specific hazards has yet to be clarified. This study therefore aimed to clarify the factors affecting Disaster Medical Assistance Team members' (n = 178) intent to engage with each type of hazard through an anonymous web questionnaire survey containing 20 questions. Our results show that the intent to engage in disaster response activities was significantly lower for chemical (50), biological (47), radiological/nuclear (58), and explosive (52) incidents compared with natural (82) and man-made hazards (82) (p < 0.01). Multiple regression analysis showed that incentives were the most common factor affecting responders' intent to engage with all hazard types, followed by self-confidence. Thus, creating a system that provides generous incentives could effectively improve disaster responders' intent to engage with specific hazards. Another approach could be education and training to increase disaster responders' confidence. We believe that the successful implementation of these measures would improve the intent of responders to engage with hazards and promote the recruitment of sufficient human resources.

Survey about Intention to Engage in Specific Disaster Activities among Disaster Medical Assistance Team Members.

INTRODUCTION: Different disaster activities should be performed smoothly. In relation to this, human resources for disaster activities must be secured. To achieve a stable supply of human resources, it is essential to improve the intentions of individuals responding to each type of disaster. However, the current intention of Disaster Medical Assistance Team (DMAT) members has not yet been assessed. STUDY OBJECTIVE: To facilitate a smooth disaster response, this survey aimed to assess the intention to engage in each type of disaster activity among DMAT members. METHODS: An anonymous web questionnaire survey was conducted. Japanese DMAT members in the nuclear disaster-affected area (Group A; n = 79) and the non-affected area (Group N; n = 99) were included in the analysis. The outcome was the answer to the following question: "Will you actively engage in activities during natural, human-made, and chemical (C), biological (B), radiological/nuclear (R/N), and explosive (E) (CBRNE) disasters?" Then, questionnaire responses were compared according to disaster type. RESULTS: The intention to engage in C (50), B (47), R/N (58), and E (52) disasters was significantly lower than that in natural (82) and human-made (82) disasters (P <.001). The intention to engage in CBRNE disasters among younger participants (age ≤39 years) was significantly higher in Group A than in Group N. By contrast, the intention to engage in R/N disasters alone among older participants (age ≥40 years) was higher in Group A than in Group N. However, there was no difference between the two groups in terms of intention to engage in C, B, and E disasters. Moreover, the intention to engage in all disasters between younger and older participants in Group A did not differ. In Group N, older participants had a significantly higher intention to engage in B and R/N disasters. CONCLUSION: Experience with a specific type of calamity at a young age may improve intention to engage in not only disasters encountered, but also other types. In addition, the intention to engage in CBRNE disasters improved with age in the non-experienced population. To respond smoothly to specific disasters in the future, measures must be taken to improve the intention to engage in CBRNE disasters among DMAT members.

Development of computer simulator 'Kawauchi Legends' as disaster response medical training software: overcoming the COVID-19 pandemic.

Medical disaster response training is provided for international students in Kawauchi Village to share the lessons learnt from the accident at Fukushima Daiichi nuclear power plant. At present, this is difficult due to the coronavirus disease 2019 (COVID-19) pandemic. The purpose of this article is to report the development of hands-on medical training software on a topic that does not require in-person attendance. The 'Kawauchi Legends' disaster simulator was developed as a useful tool to teach the medical response to various disasters, and this was applied in a 3-day webinar in October 2020. Fourteen students participated in the webinar and successfully learnt medical management, manipulating their avatars in the virtual environment. This software can be an effective substitute for in-person disaster training without physical involvement. Such innovative teaching methods mean that lessons from the Fukushima accident can continue to be shared, even in the COVID-19 pandemic situation.

Evaluation of the emergency medical system in an area following lifting of the mandatory evacuation order after the Fukushima Daiichi Nuclear Power Plant accident: A retrospective cross-sectional observational study.

ABSTRACT: Following the lifting of the evacuation order due to the Fukushima Daiichi Nuclear Power Plant accident, the medical demand and emergency medical system (EMS) in the area where the evacuation orders were lifted have not been well-investigated. This study aimed to evaluate the emergency transportation in such areas and compare the differences with areas that had minimal impact.Using the local EMS transport records, the characteristics of patients who were transferred by an EMS vehicle in Minamisoma City were collected between July 12, 2016 and July 31, 2018, and were compared between former evacuation zones and outside the evacuation zones in the city.The number of emergency transports in the study period in Minamisoma City were 325 cases in the area where the evacuation orders were lifted and 4307 cases in the other areas. The total EMS time was significantly longer in the area where the evacuation order was lifted (48 ±â€Š16 minutes) than in the other areas (40 ±â€Š15 minutes) (P < .001). In the analysis of each component of EMS times, the transport time, which is the time from departure from the patient's location to arrival at a hospital, was significantly longer in the former evacuation zone than in the other areas (16 ±â€Š9 vs 9 ±â€Š9 minutes, P < .001), suggesting that transport time contributed to the longer EMS response times.In areas where the evacuation orders were lifted, the EMS transport time was significantly longer than that in the area outside the former evacuation zone; correspondingly, the total EMS time significantly increased in the former evacuation zone. A plausible reason for this may be the closure of local medical facilities following the evacuation order after the nuclear accident.

[Questionnaire Survey of Fukushima Daiichi Nuclear Power Plant Workers in 2016 on Knowledge and Anxiety About Radiation].

The results of a survey of radiation workers suggest that they are worried about the effects of radiation exposure on health, and approximately 30% of Fukushima Daiichi Nuclear Power Plant (FDNPP) workers have anxiety. This questionnaire survey reveals that the higher the frequency of radiation education, the higher the knowledge of radiation the workers will have, and that the higher the level of knowledge, the lower the anxiety. To reduce anxiety, it is important to increase knowledge about radiation through radiation education. However, even those workers who had radiation education several times still had anxiety. According to the Ordinance on the Prevention of Ionizing Radiation Hazards, the time spent on education about the effects of radiation on the human body is only about 30 minutes. This education is not enough to reduce anxiety. FDNPP workers needed more effective education to increase their knowledge and to reduce their anxiety.

Factors associated with the intention to participate in activities during a nuclear disaster situation among firefighters.

Willingness to participate in activities during a nuclear disaster situation among firefighters is low. Thus, we aimed to identify the factors affecting the intention to participate in nuclear disaster activities. A questionnaire survey was conducted among firefighter training students (n = 186) and firefighters (n = 410), and a multivariate logistic regression analysis was performed to identify factors affecting the intention to participate in nuclear disaster activities. The percentage of students and firefighters who were willing to participate in nuclear disaster activities was 70.4% (n = 131) and 56.3% (n = 231) (P < 0.01), respectively. The factors affecting the students' intention to participant were "wish to learn more information about radiation" and "firefighters should actively work in a nuclear disaster." Meanwhile, the factors affecting the firefighters' intention to work were "have self-confidence during nuclear disaster activities," "participate if there is an incentive," "unable to get a family member to understand the need to participate in a nuclear disaster activity," and marital status. A student's decision might be strongly connected to social norms about participating in nuclear disaster activities. The willingness to participate in nuclear disaster activities among firefighters might be improved by facilitating activities that can build their self-confidence, providing sufficient incentives, and helping their families understand their work. Therefore, not only direct education for responders but also educational activities for the general public and their families are essential.

Author Correction: Reconstruction of residents' thyroid equivalent doses from internal radionuclides after the Fukushima Daiichi nuclear power station accident.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Reconstruction of residents' thyroid equivalent doses from internal radionuclides after the Fukushima Daiichi nuclear power station accident.

There is concern among residents that their children might suffer from thyroid cancer in the near future after the Fukushima Daiichi nuclear power station (FDNPS) accident. However, the demographic and geographical distribution of thyroid equivalent doses was not thoroughly evaluated, and direct thyroid measurements were conducted only for 1,200 children, whose individual thyroid doses were assessed on the basis of those measurements accounting for the dynamics of radioiodine intake. We conducted hierarchical clustering analyses of 100 or 300 randomly sampled behavioural questionnaire sheets of children from each of seven municipalities in the evacuation area to reconstruct evacuation scenarios associated with high or low exposures to plumes. In total 896 behaviour records in the Fukushima Health Management Survey were analysed to estimate thyroid equivalent doses via inhalation, using a spatiotemporal radionuclides concentration database constructed by atmospheric dispersion simulations. After a decontamination factor for sheltering and a modifying factor for the dose coefficient-to reflect lower iodine uptake rate in Japanese-were applied, estimated thyroid equivalent doses were close to those estimated from direct thyroid measurement. The median and 95th percentile of thyroid equivalent doses of 1-year-old children ranged from 0.6 to 16 mSv and from 7.5 to 30 mSv, respectively. These results are useful for future epidemiological studies of thyroid cancer in Fukushima.

The Development of an Active Learning Program for the Medical Responders in a Nuclear Disaster.

OBJECTIVE: In Japan, with the revision of the Nuclear Emergency Response Guidelines in 2015, nuclear emergency medical assistance teams responsible for the medical treatment in the acute phase of nuclear disaster have been developed nationwide. The purpose of this research is to develop active learning materials for the education of medical staff, to confirm the educational effect of the materials, and to identify the gaps in nuclear disaster risk reduction in Japan. METHODS: We established a working group and created active learning materials. We trained members of the nuclear emergency medical assistance team using the developed active learning materials and then conducted a questionnaire survey for trainees who participated in the training. RESULTS: Regarding the developed teaching materials, out of 33 trainees, 33 (100%) answered "easy to understand" or "a little understandable" to the item dealing with how to use the radiation detectors and attaching/detaching personal protective equipment. Regarding the simulation about practicing hospital support and medical provision, 3 (8%) answered "a little confusing." CONCLUSION: The study demonstrated that the developed materials have an educational effect. Additionally, the results of the trainee questionnaire showed the necessity for improvement in the triage system and new protocols to help both the patients and responders.

Estimated Thyroid Inhalation Doses Based on Body Surface Contamination Levels of Evacuees After the Fukushima Daiichi Nuclear Power Plant Accident.

Doses of inhaled radionuclides received during evacuation might be correlated with amounts of those radionuclides on an evacuee's body surface. The purpose of the present study was to estimate thyroid equivalent doses based on body surface contamination measured with a Geiger-Mueller survey meter on 2,087 evacuees from Tomioka, Okuma, Futaba, Naraha, Namie, Minamisoma, and other municipalities in Japan. The measurement value in cpm was translated into Bq cm according to the radionuclide composition obtained by germanium gamma-spectrometry analyses of two persons' clothing. Thyroid equivalent dose by inhalation was estimated by two-dimensional Monte Carlo simulation based on the distribution of body surface radionuclide concentration and a uniform distribution of deposition velocity. For evacuees exposed twice on 12 and 15 March, the mean, median, and 90th percentile of inhalation thyroid equivalent dose for 1-y-old children were 21.4 mSv, 4.7 mSv, and 40.1 mSv for the Namie group; 7.3 mSv, 5.1 mSv, and 14.8 mSv for the Minamisoma group; and 2.3 mSv, 0.5 mSv, and 4.0 mSv for the group comprising Tomioka, Okuma, Futaba, and Naraha. These estimates are smaller than estimates in the United Nations Scientific Committee on the Effects of Atomic Radiation 2013 report but closer to estimates based on direct thyroid I measurement or indirect estimates based on Cs measurements made with a whole-body counter under the assumption that the ratio of I to Cs is 3.8.

Lexical analysis suggests differences between subgroups in anxieties over radiation exposure in Fukushima.

Although many experts have attempted communication about radiation risk, fears about radiation exposure stemming from the Fukushima Daiichi Nuclear Power Plant accident remain deeply rooted. The characteristics of the anxiety vary with social background, which makes it difficult to alleviate with one approach. Our ultimate goal is therefore to create risk-communication materials tailored to various groups with differing social backgrounds. Towards that end, the purpose of the present study was to clarify potential factors associated with radiation-related anxieties within these groups. After obtaining informed consent, we conducted focus group interviews (FGIs) with Fukushima residents from various social groups, including evacuees, emergency responders, government personnel, medical staff, and decontamination workers. We obtained narrative comments specifically related to the following two themes: (i) lessons learned (at work or home) in light of one's position in society, and (ii) health issues. After transcribing the comments, we examined potential factors associated with radiation-related anxieties using both quantitative and qualitative study methods simultaneously, using the KH Coder software and the Steps for Coding and Theorization (SCAT) method respectively. FGIs were undertaken with 141 persons. Categories, words and storylines extracted in this study might indicate potential anxieties that are unique to each group, but our analysis also suggested that some anxieties were common to all groups. We expect to continue the analyses and, ultimately, to establish group-tailored risk-communication materials for achieving our final goal of adapting and better managing risk-communication efforts to help people deal more effectively with the scientific, technological and societal changes that came about after the disaster.