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After disasters, direct deaths and secondary health effects, such as diabetes and psychological distress, can occur. It is critical to compare the magnitudes of these risks to promote effective public health measures. In this study, we used the loss of happy life expectancy (LHpLE) to compare the risks associated with diabetes, psychological distress, and radiation-induced cancer after the 2011 Fukushima disaster. Two questionnaire surveys were conducted on people affected by the disaster to investigate the potential associations between diabetes and psychological distress, as well as breast cancer and reduced emotional happiness, with 680 and 582 participants, respectively. Additionally, we calculated the LHpLE owing to these risks. Although no significant reduction was found in emotional happiness due to diabetes or breast cancer, a significant reduction occurred due to psychological distress (0.265 and 0.476 for males and females, respectively). In the population aged 40–74 years, the LHpLE due to radiation-induced cancer, diabetes, and psychological distress were 0.0013, 0.14, and 0.21 years, respectively. This suggests that the association of LHpLE with diabetes and psychological distress was over two orders of magnitude greater than that associated with radiation-induced cancer. Within 7 years following the disaster, LHpLE due to diabetes increased, highlighting that diabetes is an ongoing issue. Therefore, this novel indicator of the LHpLE can provide a foundation for promoting effective public health measures following disasters.

Little is known about how crises might affect the long-term uptake of breast cancer screening programs. This study aimed to clarify the long-term trend of breast cancer screening program uptake in Minamisoma City following the 2011 Triple Disaster in Fukushima, Japan (earthquake, tsunami, and nuclear disaster), and to evaluate the factors associated with this uptake. This study retrospectively analyzed data from the Basic Resident Registry and Breast Cancer Screening Program in Minamisoma City following the Triple Disaster. We calculated the annual breast cancer screening uptake rate for women aged 40–74 years who were of an even-numbered age at the end of each fiscal year and the incidence of at least one instance of uptake of the breast cancer screening initiative during the biennial intervals. We further performed cross-sectional and longitudinal regression analyses for the biannual screening uptake and investigated its associated factors. Breast cancer screening participation rates were 19.8% and 18.2% in 2009 and 2010, respectively. They decreased to 4.2% in 2011, and gradually increased thereafter, reaching the pre-disaster level of 20.0% in 2016. Similar but longer decrease of the uptake was observed in the biannual screening uptake rate. No pre-disaster screening uptake between 2009 and 2010, those living alone, or those who were evacuated, were factors that were found to be associated with non-uptake of the breast cancer screening program following the 2011 disaster. This study showed a long-term decline in breast cancer screening uptake in the area affected by the Triple Disaster, which was the most severe among those under evacuation, those who were isolated, and those without previous uptake. The insights emerging from this study could be used to increase awareness of this issue and establish potential countermeasures.

BackgroundDuring a global infectious disease pandemic such as the coronavirus disease 2019 (COVID-19), individuals’ infection prevention/risk-taking behaviours are likely to differ depending on their health literacy and beliefs regarding the disease. To effectively promote infection prevention behaviours, it is necessary to enable information dissemination and risk communication that consider individuals’ health literacy and beliefs. In this study, we exploratorily characterised segments based on individual health literacy and beliefs regarding COVID-19 among the Japanese during the early stage of the COVID-19 pandemic, and investigated whether infection prevention/risk-taking behaviours and fear of COVID-19 differed among these segments.MethodsIn this study, we conducted two web-based longitudinal surveys in Japan (PHASE 1, 1–30 November 2020, 6,000 participants; PHASE 2, 1–31 December 2020, 3,800 participants). We characterised segments of the target population using cluster analysis on health literacy and beliefs regarding COVID-19 obtained in PHASE 1. We further investigated the associations between the clusters and infection prevention/risk-taking behaviours and fear of COVID-19, obtained from PHASE 2.ResultsFive clusters were identified: ‘Calm/hoax denial’, ‘Hoax affinity/threat denial’, ‘Minority/indifference’, ‘Over vigilance’, and ‘Optimism’. There were significant differences in infection prevention/risk-taking behaviours and fear of COVID-19 among the five clusters. The belief in susceptibility to infection, rather than affinity for hoaxes and conspiracy theories, was coherently associated with infection prevention/risk-taking behaviours and fear of infection across clusters. This study provides foundational knowledge for creating segment-specific public messages and developing interactive risk communication to encourage infection prevention behaviours.

Recognizing the risk of pandemic and the importance of monitoring and data sharing, we highlight the importance of establishing a global wastewater surveillance consortium, particularly under the umbrella of an international organization such as WHO, to strengthen future pandemic preparedness.

In this study, we aimed to use the loss of happy life expectancy (LHpLE), an indicator that enables risk assessment considering wellbeing, to compare the risks of environmental carcinogenic chemicals in Japan. First, we surveyed Japanese people to determine their emotional happiness by age and sex and evaluated whether cancer incidence reduced emotional happiness. Questionnaires were administered to a general population panel and a panel of patients with cancer in 2022, recruiting a predetermined number of responses of 5000 and 850, respectively. Second, using the survey data, LHpLE was calculated for radon, arsenic, and fine particulate matter (aerodynamic diameter 2.5) and compared to psychological distress, considering increased mortality and decreased emotional happiness due to these risks. We discovered no significant decrease in emotional happiness due to cancer incidence and no significant associations between emotional happiness and cancer type, history, or stage. LHpLE was calculated to be 6.4 × 10−3years for radon, 2.6 × 10−3years for arsenic, 1.1 × 10−2years (2012 exposure) and 8.6 × 10−4years (2020 exposure) for PM2.5, and 9.7 × 10−1years for psychological distress. The fraction of losses caused by these carcinogenic chemicals to HpLE exceeded 10−5, suggesting that risk reduction for these chemicals is important in environmental policies. The LHpLE indicator allows for comparing different types of risks, such as environmental chemicals and psychological distress. This is the first study to compare chemical risks using the LHpLE indicator.

Objective: Those affected by the Fukushima disaster have reported a decline in well-being. Although listening to music is expected to promote well-being, no study has revealed this association after a disaster. This study’s objective is to clarify the association between well-being and music listening habits in the aftermath of the Fukushima disaster. Methods: A self-report online survey was conducted with 420 residents who were asked to rate 5 types of well-being: life satisfaction, positive emotion, negative emotion, psychological distress, and mental health changes after the Fukushima disaster. To meet inclusion criteria, the participants had to be research company monitors between the ages of 20 and 59 and living in Fukushima Prefecture at the time of the survey. Their music listening habits (eg, recent favorite music) and demographic information (eg, evacuation experience due to the disaster: 20.7%) were also collected. We examined the associations between well-being and music listening habits by univariate analysis followed by a logistic analysis with an adjustment for covariates. Results: Positive emotions were significantly associated with any type of music listening habits that participants practiced. We also observed gender and age differences between the associations. Conclusion: This study provides foundational insights into the role of music in improving post-disaster well-being.

Background Discrepancies between parents' reports of paternal parenting have been gaining attention, but epidemiological evidence is scarce in Asia. This study aimed to clarify agreement/discrepancy between paternal and maternal recognition of paternal parenting, and the association between actual paternal parenting time and background factors. Methods Data from couples whose children attended 4-month-child health check-ups in Fukushima City were analyzed (N = 509). Based on paternal recognition of paternal parenting (PRPP) and maternal recognition of paternal support (MRPS), couples were classified into four groups. Each group's paternal household work and parenting time were analyzed. Univariable and multivariable analysis were performed to investigate the association between agreement/discrepancy and background factors of children and parents. Results Frequency of positive agreement (PRPP+ and MRPS+) was 83.9%, whereas negative agreement (PRPP- and MRPS-) was 2.6%. As for discrepancy, PRPP+ and MRPS- was 8.4% and PRPP- and MRPS+ was 5.1%. Fathers' total median parenting time was 2 (weekdays) and 6 (weekends) hours, and showed significant differences among the four groups. Multivariable analysis revealed that compared to positive agreement, maternal mental health condition and pregnancy intention were significantly associated with the discrepancy PRPP+ and MRPS-, paternal mental health condition and marital satisfaction with the discrepancy PRPP-and MRPS＋, and maternal mental health condition with negative agreement. Conclusions We identified differences in parenting time and mental health characteristics among couples depending on agreement/discrepancy in recognition of paternal parenting. Assessing both parents' profiles is necessary in clinical practice to promote paternal participation in childcare.

Since the Fukushima accident, radiation risk perception has been of public concern. Factors related to regional differences in radiation risk perception and the role that knowledge of radiation effects plays are still not clearly understood. Here, we first assessed the validity of the Lindell radiation risk perception scale by comparing it with the mortality rate of traffic accidents. We then investigated the relationship between the perceptions and both the geographical regions and the knowledge of genetic effects and, further, verified the mediating role of knowledge in the perception. The sample comprised of 832 participants who responded to an online questionnaire in August 2018 from Tokyo and Fukushima. There was a significant association between the Lindell scale and the perceived magnitude of genetic risk relative to traffic accident mortality. Knowledge of genetic effects, after the atomic bombs, was associated with perceptions of lower genetic risks. The relationship between geographical region and risk perception was mediated by knowledge. However, approximately 40% of those who had knowledge still perceived a high risk, indicating that perception is not governed by knowledge alone. In addition to efforts to share knowledge, it is important to interactively communicate regarding risk to alleviate the anxiety felt by individuals.

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Given that mass gathering events involve heterogeneous and time-varying contact between residents and visitors, we sought to identify possible measures to prevent the potential acceleration of the outbreak of an emerging infectious disease induced by such events. An individual-based simulator was built based on a description of the reproduction rate among people infected with the infectious disease in a hypothetical city. Three different scenarios were assessed using our simulator, in which controls aimed at reduced contact were assumed to be carried out only in the main event venue or at subsequent additional events, or in which behavior restrictions were carried out among the visitors to the main event. The simulation results indicated that the increase in the number of patients with COVID-19 could possibly be suppressed to a level equivalent to that if the event were not being held so long as the prevalence among visitors was only slightly higher than that among domestic residents and strict requirements were applied to the activities of visitors.

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.

Vaccine hesitancy is a global public health threat. We present unique data that characterises those who experienced reversals of COVID-19 vaccination hesitancy in Japan.We administered a questionnaire on vaccination intention among 30053 Japanese adults aged 20 years or older before the COVID-19 vaccination was available to the general population (first survey) and conducted a follow-up survey on vaccination status one year later in February 2022 (second survey). Those who responded in the first survey that they did not intend to be vaccinated or were unsure and then responded in the second survey that they were vaccinated or intend to be vaccinated were asked about the reasons for their change of heart. Based on previous literature and expert opinion, 31 reasons for changing vaccination intention were compiled and respondents were asked to choose which among them applied to themselves, with multiple responses possible. Based on the results of those responses, each individual was then clustered using the Uniform Manifold Approximation and Projection (UMAP) dimensionality reduction technique and Ordering Points To Identify the Clustering Structure (OPTICS) algorithm. We then identified unique characteristics among each of the sub-populations (clusters).In the second survey we received 19195 responses (response rate 63.9%), of which 8077 responded 'no' or 'not sure' in the first survey regarding their intention to be vaccinated. Of these, 5861 responded having received or intending to receive the vaccine (72.6%). We detected six and five sub-populations (clusters) among the 'no' group and 'not sure' group, respectively. The clusters were characterized by perceived benefits of vaccination, including the COVID-19 vaccine, awareness of the COVID-19 vaccination status of those close to them, recognition of the social significance of COVID-19 vaccination for the spread of infection, and dispelled concerns about short-term adverse reactions and the safety of the COVID-19 vaccine. Work and personal relationship reasons were also found to be a unique overarching reason for vaccination changes of heart only among those who did not intend to vaccinate.Those who changed their intention to accept COVID-19 vaccination as well as their unique characteristics as detailed in this study will be important entry points when discussing how to promote vaccination to those who are hesitant to vaccinate in the future.The present work was supported in part by a grant from the Kanagawa Prefectural Government of Japan and by AIST government subsidies.

To determine the relationship between family uncertainty and family quality of life (QOL) during the recovery period of patients with cerebrovascular disease in Japan, and the factors that influence family uncertainty.Data were collected from copies of patient medical files and interviews with family members of 85 patients admitted to two rehabilitation wards in Japan. Family uncertainty was measured using the Japanese version of the Managing Uncertainty in Illness Scale-Family Member form (MUIS-FM) and family QOL using the World Health Organization Five Well-Being Index (WHO-5). Multiple linear regression analysis was applied to investigate associated factors.WHO-5 score was significantly negatively associated with MUIS-FM score (β = - 0.236, p = 0.03); other factors associated with MUIS-FM score were the Care Shared Decision-Making Questionnaire for care providers score (β = - 0.384, p 0.001), Short Intolerance of Uncertainty Scale score (β = 0.296, p = 0.001), and history of surgical treatment (β = 0.199, p = 0.032).Family QOL could be improved by reducing family uncertainty. It is also suggested that promoting shared decision-making between healthcare providers and patients' families may help reduce family uncertainty. It is necessary to take into account not only family intolerance of uncertainty but also uncertainty that varies by type of acute care provided.

BackgroundRapid antigen tests have been used to prevent the spread of the coronavirus disease 2019 (COVID-19); however, there have been concerns about their decreased sensitivity to the Omicron variant.AimsIn this study, we compared the sensitivity and specificity of the rapid antigen and the polymerase chain reaction (PCR) tests among the players and staff members of the Japan Professional Football League and clubs. Furthermore, we evaluated the relationship between the sensitivity and the duration from the onset of the symptoms to testing, the manufacturer of the rapid antigen test kits, and the PCR test analyte.Design and methodsThis was a retrospective observational study. We used 656 results from both the rapid antigen and PCR tests for COVID-19 using the analytes collected on the same day from January 12 to March 2, 2022, during the Omicron variant outbreak in Japan.ResultsThe sensitivity of the rapid antigen test compared with the PCR test was 0.63 (95% confidence interval: 0.54–0.72) and the specificity was 0.998 (95% confidence interval: 0.995–1.000). There were no significant associations between the sensitivity and the duration from the onset of the symptoms to testing (including asymptomatic cases in the category), vaccination status, manufacturer of the rapid antigen test kit or PCR analyte (P > 0.05) with small effect sizes (Cramer’s V or φ: ≤ 0.22).ConclusionsEven during the Omicron outbreak, the sensitivity of the rapid antigen tests did not depend on the duration from the onset of the symptoms to testing.

We developed a mobile application (app) to help communication between support providers and residents who have returned from evacuation after the Fukushima nuclear power plant accident. Surveys were conducted among returning residents and support providers in coastal areas of Fukushima Prefecture, from which application functions and layout were decided. App functions were included to estimate external exposure, monitor health, and facilitate interactive health counseling.

We developed a mobile application (app) to help communication between support providers and residents who have returned from evacuation after the Fukushima nuclear power plant accident. Surveys were conducted among returning residents and support providers in coastal areas of Fukushima Prefecture, from which application functions and layout were decided. App functions were included to estimate external exposure, monitor health, and facilitate interactive health counseling.

This paper reports on the IAEA’s Consultancy Meeting on “low-dose radiation for patients and population —Science, Technology and Society (STS) concepts for communication and perception among medical doctors and stakeholders—”, which was held on October 21 and 22, 2020. The meeting consisted of seven presentation sessions, with a total of 27 presentations and 39 participants from seven countries. The meeting focused on various areas including environmental, food, and personal dosimetry; radiation and other secondary health effects after nuclear disasters; communication between medical professionals and patients or residents; and medical education on nuclear accidents. This meeting was convened to discuss STS perspectives related to nuclear emergencies, to share the findings of the Fukushima Health Management Survey and the current situation in Fukushima with international experts. The meeting confirmed the importance of coordinated recovery of affected areas and global preparedness in the aftermath of nuclear accidents.

Since the Fukushima accident, there has been an increasing discussion on post-accident radiation protection as well as nuclear regulation and management. This study assessed the general content of discussions during the chronic phases after the accident, and analyzed the changes over the years in discussion on radiation protection measures related to the accident by focusing on the meeting minutes of the Nuclear Regulation Authority, Japan from 2012 to 2018 using the method of text mining. The analysis revealed that while the authority’s main focus was on regulation and management regarding the safety of nuclear power plants, in addition to emergency measures for the future (especially in matters such as evacuation), discussions were also held on radiation protection measures for residents and workers and risk communication in the period following the accident. The authority was observed to have dynamically tackled the issues that were regarded as most urgent after the accident and gradually shifted its focus to mid- to long-term issues. In the aftermath of a nuclear accident, it is important for the authorities responsible for nuclear regulation to deepen their knowledge of social measures such as evacuation, return of residents, and risk communication, and strengthen cooperation with experts from other fields.

ObjectivesThis study aimed to determine cause-specific years of life lost (YLL) changes between predisaster and postdisaster in disaster-affected municipalities, compared with the national average. We estimated the YLL in Soma and Minamisoma cities (the subject area) in Fukushima, Japan, where the tsunami and the nuclear accident hit in 2011.ParticipantsWe used vital registration records from a national survey conducted between January 2006 and December 2015. We analysed 6369 death data in the predisaster period (2006–2010) and 6258 death data in the postdisaster period (2011–2015).MethodsWe incorporated vital statistics data as follows: age-based, sex-based and International Classification of Diseases, 10th Revision-based cause-specific deaths and calculated YLLs by ages 0, 40, 65 and 75 and sex for attributable causes of death for heart diseases, cerebrovascular diseases, pneumonia, all cancers and specific cancers; breast cancer, colorectal cancer, leukaemia, lung cancer, stomach cancer and uterine cancer for predisaster and postdisaster in the subject area.ResultsYLL attributed to heart diseases for males showed no decrease and YLL postdisaster was 0.37 years larger than that of the national average at age 0. The difference was −0.17 (95% uncertainty interval: −0.40 to 0.05) years at age 65. It decreased for females; the difference was 0.37 (0.18–0.57) years after the disaster. YLL decrease (that is, difference) in cerebrovascular diseases at age 0 was 0.27 (0.09–0.44) years and 0.18 (0.04–0.32) years; however, the YLLs postdisaster were still 0.24 and 0.25 years larger than those for the national average for males and females, respectively. YLL attributed to cancer did not increase even after the nuclear disaster.ConclusionsWe specified the causes of death to be reduced in disaster-affected areas in the future. This study emphasised the importance of understanding how the health situation changed for the whole society of the area from a comprehensive perspective, rather than focusing only on small mortality increases.

We developed an environmental exposure model to estimate the Coronavirus Disease 2019 (COVID-19) risk among participants at an outdoor music festival and validated the model using a real cluster outbreak case. Furthermore, we evaluated the extent to which the risk could be reduced by additional infection control measures such as negative proofs of antigen tests on the day of the event, wearing masks, disinfection of environmental surfaces, and vaccination. The total number of already- and newly-infected individuals who participated in the event according to the new model was 47.0 (95% uncertainty interval: 12.5–185.5), which is in good agreement with the reported value (45). Among the additional control measures, vaccination, mask-wearing, and disinfection of surfaces were determined to be effective. Based on the combination of all measures, a 94% risk reduction could be achieved. In addition to setting a benchmark for an acceptable number of newly-infected individuals at the time of an event, the application of this model will enable us to determine whether it is necessary to implement additional measures, limit the number of participants, or refrain from holding an event.

Large-scale decontamination work has been carried out in the aftermath of the Fukushima Daiichi nuclear power station accident in Japan in 2011. The soil that was removed and the wastes that were generated during the decontamination will be finally disposed of outside Fukushima Prefecture by 2045. To ensure successful and socially acceptable implementation of this final disposal process, it is essential to have a good understanding of what is considered important by the public. We used a choice-based conjoint analysis in the form of a web-based questionnaire to examine the relative importance of several factors in the choice of the final disposal sites of the removed soil and incinerated ash of the wastes. The questionnaires covered four attributes and 12 levels, namely the distance between the disposal site and a person’s residential area, procedural fairness (decision process), distributive fairness (direct mitigation of inequity through multiple siting locations), and the volume and radioactivity of the substances to be disposed. Responses were received from 4000 people nationwide, excluding Fukushima residents. The results showed that the respondents gave high importance to choosing sites that were far from residential areas and to the two types of fairness, especially distributive fairness. The respondents showed no preference for the volume and radioactivity. This indicates that the public cares about the fairness of the siting for the final disposal sites and feels uncomfortable with plans for a final disposal site located close to them. Distributive fairness is necessary to pursue consensus in addition to procedural fairness.

Healthcare students are key resources after nuclear disasters. Healthcare students at Fukushima Medical University volunteered after the Great East Japan Earthquake and Fukushima nuclear accident. At the time of the disaster, healthcare students, who were in a position between medical and non-medical people, listened to the various concerns and worries of victims. Specifically, they established the Fukushima WILL – a disaster medical club. These activities have continued for about 10 years after the Fukushima disaster. In this paper, we introduce lessons from and perspectives for healthcare student volunteer activities during disasters. When volunteering, healthcare students needed to acquire sufficient medical knowledge and skills as well as display effective communication skills considering the background of the affected people. In addition, to respond to potential future disasters, healthcare students need to proactively, independently, and repeatedly learn about diseases that are likely to occur in shelters and how to prevent them. Seminars and workshops should be implemented to ensure students are taught these lessons and provided daily training on disaster response.

Isolation of close contact people and negative test certification are used to manage the spread of new coronavirus infections worldwide. These effectively prevent the spread of infection in advance, but they can lead to a decline in socio-economic activity. Thus, the present study quantified the extent to which isolation and negative test certification respectively reduce the risk of infection. To this end, a discrete-time SEIR model was used as the infectious disease model, and equations for calculating the conditional probability of non-infection status given negative test results on two different days were derived. Then the respective non-infection probabilities with two negative PCR test results, and with one negative PCR test result and one antigen test result, were quantified. By substituting initial parameters of the SEIR model into these probabilities, the present study revealed the following: (1) isolating close contact individuals can reduce by 80% the risk of infection during the first five days, but five more days are needed to reduce the risk 10% more, and seven more days to reduce the risk 20% more; and (2) if an individual with a negative PCR test result has a negative antigen test result the next day, then his or her infection probability is between 0.6% and 0.7%. Our results show that five-day isolation has a proportionally greater effect on risk reduction, compared to longer isolation; and thus, if an isolation period of longer than five days is contemplated, both the risk reduction and the negative effects from such increased isolation should be considered. Regarding negative test certification, our results provide those in managerial positions, who must decide whether to accept the risk and hold mass-gathering events, with quantitative information that may be useful in their decision-making.

We investigated whether differences in presentation style affect risk perception, understanding, preference, and trust toward data. One hundred and sixty Fukushima Medical University students were shown the lifetime probability of breast cancer incidence for a 50-year-old woman, presented in both a pictogram and a horizontal bar graph format. Participants rated each of the following on a five-point scale by looking at each figure: risk perception, perceived truth of data, and comparative risk perception. The perceived truth of data was high for pictograms, especially among men and among those defined as having lower health literacy. Women correctly perceived the risk of breast cancer as higher than that of dying in a car accident when the data were presented on a pictogram. There was no difference in risk perception, perceived truth of data, or comparative risk perception arising from being shown the bar graphs and the pictograms in a particular order. There was a 50/50 split on which type of graph was perceived as easier to understand, but the preference was for the pictogram format. It is important to devise a visual method of health communication that considers the purpose of the information and characteristics of the target audience.

While mass gathering events have resumed in conjunction with vaccine-testing (VT) packages, their effects on reducing COVID-19 risk remain unclear. Here, we used an environmental exposure model to analyze the effects of vaccinations and proof of negative test results on reducing infection risk and serious illness among spectators at mass gathering events. We then analyzed the difference in risk with and without VT and regular seat zoning. Risk of infection and serious illness were quantified using a model incorporating parameters such as vaccination coverage, vaccine prevention effectiveness, and sensitivity of polymerase chain reaction (PCR) or qualitative antigen tests. When vaccine prevention effectiveness was 50% (corresponding to 4 months for the delta variant and 1–2 months for the omicron variant after the second vaccine dose), the risk of infection and serious illness among vaccinated spectators were 0.32–0.40 and 0.13–0.16 times of those who tested negative, respectively. In contrast, the risks of infection and serious illness among vaccinated spectators without measures such as mask wearing were 4.0 and 1.6 times higher than those among unvaccinated spectators with such measures, respectively. The risk of infection with an 80% vaccination coverage and a vaccine prevention effectiveness of 20% (corresponding to 5–6 months for the delta variant or 3–4 months for the omicron variant after the second vaccine dose) was comparable to that of a 20% vaccine coverage and a vaccine prevention effectiveness of 80% (corresponding to 1–3 months for delta variant after the second vaccine dose). Regarding zoning, there was little difference in risk with a vaccination coverage of ≥80%. Adherence to individual measures after vaccination and maintenance of high vaccine effectiveness among spectators at stadiums are important for reducing risk of infection and serious illness. Furthermore, seat zoning did not affect overall infection risk reduction.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to be present in sewage, and wastewater -based epidemiology has attracted much attention. However, the physical partitioning of SARS-CoV-2 in wastewater and the removal efficiency of treatment systems require further investigation. This study aimed to investigate the de-tectability and physical partitioning of SARS-CoV-2 in wastewater and assess its removal in a large-scale septic tank employing anaerobic, anoxic, and oxic processes in a sequential batch reactor, which was installed in a coronavirus disease 2019 (COVID-19) quarantine facility. The amount of SARS-CoV-2 RNA in wastewater was determined with polyethylene glycol (PEG) precipitation followed by quantitative polymerase chain reaction (qPCR), and the association of SARS-CoV-2 with wastewater solids was evaluated by the effect of filtration prior to PEG precipitation (pre-filtration). The amount of SARS-CoV-2 RNA detected from pre-filtered samples was substantially lower than that of samples without pre-filtration. These results suggest that most SARS-CoV-2 particles in wastewater are associ-ated with the suspended solids excluded by pre-filtration. The removal efficiency of SARS-CoV-2 in the septic tank was evaluated based on the SARS-CoV-2 RNA concentrations in untreated and treated wastewater, which was determined by the detection method optimized in this study. Escherichia coli and pepper mild mottle virus (PMMoV) were also quantified to validate the wastewater treatment system's performance. The mean log10 reduction values of SARS-CoV-2, E. coli, and PMMoV were 2.47 (range, 2.25-2.68), 2.81 (range, 2.45-3.18), and 0.66 (range, 0.61-0.70), respec-tively, demonstrating that SARS-CoV-2 removal by the wastewater treatment system was comparable to or better than the removal of fecal indicators. These results suggest that SARS-CoV-2 can be readily removed by the septic tank. This is the first study to determine the removal efficiency of SARS-CoV-2 in a facility-level sequencing batch activated sludge system.

Disasters, pandemics, and their response measures can have secondary effects on the physical and psychological health of affected populations. Identifying populations vulnerable to these effects is beneficial for promoting effective health and prevention strategies. Using health insurance receipt data from 2009 to 2020, we assessed changes in prevalence of major non-communicable diseases (NCDs), including hypertension, hyperlipidemia, diabetes, and mental disorders, among affected populations before and after the Fukushima disaster and coronavirus disease (COVID-19) outbreak in Japan. Furthermore, age and sex groups with the largest increases in prevalence after these events were identified. The participants of this study were members of the Employees’ Health Insurance scheme, including employees of companies and their dependent family members. The dataset was provided by JMDC Inc. The annual age-adjusted prevalence of each disease was used to calculate the ratio of disease prevalence before and after the events. After the Fukushima disaster, hypertension, hyperlipidemia, and diabetes generally increased over a 9-year period in Fukushima Prefecture. The increase in the prevalence rate of these three NCDs and mental disorders were the highest among females aged 40–74 years compared to males and the other age groups. The prevalence of all four diseases increased after the COVID-19 outbreak in Japan, with marked increase in males aged 0–39 years. Populations that have experienced secondary health effects such as NCDs are unique to each disaster or pandemic, and it is important to provide tailor-made public health support among populations in accordance to the type of disasters and pandemic.HighlightsWe assessed secondary health effects of Fukushima disaster and COVID-19 pandemicNon-communicable diseases increased after the disaster and COVID-19 pandemicThe increase rates were higher among females aged 40–74 years after the disasterThe increase rates were higher among males aged 0–39 years after COVID-19 pandemicIt is important to provide tailor-made public health support among populations

ObjectivesRapid antigen tests have been used to prevent the spread of the COVID-19; however, there have been concerns about their decreased sensitivity to the Omicron variant. In this study, we assessed the sensitivity and specificity of the rapid antigen test compared with the PCR test among the players and staff members of the Japan Professional Football League and clubs. Furthermore, we evaluated the relationship between the sensitivity and the duration from the onset of symptoms to testing or vaccine status.DesignThis was a retrospective observational study.MethodsWe used 656 results from both the rapid antigen and PCR tests for COVID-19 using samples collected on the same day from 12 January to 2 March 2022, during the Omicron variant outbreak in Japan.ResultsThe sensitivity of the rapid antigen test compared with the PCR test was 0.63 (95% CI: 0.53 to 0.73) and the specificity was 0.998 (95% CI: 0.995 to 1.000). There were no significant associations between the sensitivity and the duration from the onset of symptoms to testing (including asymptomatic cases in the category) or vaccination status (p>0.05) with small effect sizes (Cramer’s V or φ: ≤0.22).ConclusionsEven during the Omicron outbreak, the sensitivity of the rapid antigen tests did not depend on the duration from the onset of symptoms to testing.

Understanding COVID-19 risk perception may help inform public health messaging aimed at encouraging preventive measures and improving countermeasures against the pandemic. We conducted an online survey of 29,708 Japanese adults in February 2021 and estimated the associations between COVID-19 risk perception and a broad array of individual factors. Two logistic regressions were constructed to estimate factors associated with the risk perception of COVID-19 (defined as responding that one might become infected within the next 6 months), and of severe illness among those who responded that they might become infected (defined as responding that one would become severely ill). After adjusting for covariates, those with a higher perceived risk of the COVID-19 vaccine had higher odds of risk perception for both infection and severe illness. Interestingly, those with higher odds of risk perception of being infected were more likely to report obtaining their information from healthcare workers whereas those with lower odds were more likely to report obtaining their information from the Internet or the government; those with lower odds of risk perception of being severely ill were more likely to report obtaining their information from the Internet. The higher the trust level in the government as a COVID-19 information source, the lower the odds of both risk perception of being infected and becoming severely ill. The higher the trust levels in social networking services as a COVID-19 information source, the higher the odds of risk perception of becoming severely ill. Public health messaging should address the factors identified in our study.

Prejudice related to the coronavirus disease 2019 (COVID-19) is a social issue worldwide. A possible psychological factor that promotes prejudice is the belief in just deserts (BJD) regarding individuals infected with COVID-19 (i.e., the belief that the infected individual deserves to be infected). The BJD is based on the belief in immanent justice. It is reportedly higher in Japan than in other countries. Therefore, we conducted a cross-sectional study to investigate the BJD among Japanese individuals and clarify its associations with demographic factors or infection-related and socio-psychological characteristics. To this end, we conducted an online questionnaire survey in Japan from August 7–8, 2020, with 1,207 respondents aged 20–69 years. We performed screening to exclude inappropriate responses. We investigated the association between the BJD and demographic factors such as gender and age. We also investigated the association between the BJD and infection-related and socio-psychological characteristics, including risk perception of COVID-19 infection and human rights restrictions (i.e., the degree of agreement with government restrictions on individuals’ behavior during emergencies). Among the surveyed items, human rights restrictions showed a strong association with BJD, followed by risk perception of COVID-19 infection. Men had a slightly higher BJD than women. Our study is significant in that it is the first to investigate the items associated with the BJD, thereby providing foundational information for revising individual perceptions of justice related to COVID-19 and solving prejudice-related issues.

Wastewater-based epidemiology was implemented in the Olympic and Paralympic Village to better understand COVID-19 incidence. SARS-CoV-2 RNA was detected in a number of wastewater samples even when no positive individual was identified in the corresponding areas. Wastewater-based epidemiology can be a useful tool to control infections at mass gatherings.

Background: Digital tools can be powerful and effective in connecting people with life-saving and health-promoting support when facing a health crisis. To develop a digital application for radiation protection and health promotion for evacuees returning home after the Fukushima nuclear accident, we conducted a needs assessment survey and explored the association of people’s eHealth literacy (eHL) level with their digital tool knowledge, attitudes, and practice (KAP). Methods: From 339 responses to an online survey, data from 264 lay persons were analyzed. The KAP items were those used in a prior EU project, and eHL levels were assessed with a Japanese version of the eHealth Literacy Scale. Results: Multivariable analyses showed significant associations between eHL and the digital tool KAP for radiation protection (knowledge: adjusted odds ratio (aOR) = 1.10, attitude: 1.06, practice: 1.10) and for health promotion (knowledge: aOR = 1.13, practice: 1.16). Conclusions: People with a higher eHL had a more positive KAP. For those with a lower eHL, we are formulating easy-to-understand explanations to promote the utilization of the digital tool and enthusiasm for future community-oriented digital tools.

Background: individual preventive behaviors are one of the key measures needed to prevent the spread of COVID-19. This study sought to identify the factors associated with the adoption of COVID-19 preventive measures, focusing specifically on information sources. Methods: we conducted a nationally representative cross-sectional survey of 30,053 Japanese adults in February 2021. The survey asked about socioeconomic, health-related, and psychological characteristics, attitudes toward immunization, and the use of information sources regarding COVID-19. We have constructed multivariable logistic regression to estimate the factors associated with the adoption of three preventive measures: 3Cs avoidance, hand hygiene and respiratory hygiene. Results: socioeconomic variables, psychological variables, and the use of information sources are significantly associated with the adoption of preventive measures. The more information sources one uses, the more likely one is to adopt preventive measures. Trust in healthcare professionals is positively associated with adopting preventive measures. On the other hand, negative correlations between trust in social media and preventive behaviors were observed. Conclusions: encouraging access to multiple information sources, utilizing communication channels, and modifying messaging according to target groups are essential to promote COVID-19 preventive measures.

Research characterizing changes of heart with respect to vaccine intention is scarce, and very little research considers those who were initially vaccine willing but became hesitant. Here, we sought to assess the factors related to reversals of vaccine willingness.We conducted a longitudinal, national survey on vaccination intention among Japanese adults aged 20 years or older, with the first questionnaire performed in February-March 2021 (Of 11,118 (57.9%) respondents who previously expressed interest in vaccination, 10,684 (96.1%) and 434 (3.9%) were in the vaccine willing and hesitant groups, respectively. Several covariates were found to significantly predict vaccine hesitancy, including marital status, influenza vaccine history, COVID-19 infection/testing history, engagement in COVID-19 preventive measures, perceived risks/benefits of the COVID-19 vaccine, and attitudes regarding vaccination policies and norms. The use of certain information sources was also associated with vaccine hesitancy.Sociodemographic, health-related, psychologic/attitudinal, and information-related variables predicted the development of vaccine hesitancy among those with prior willingness. Most of these predictors were also associated with vaccination status.The present work was supported in part by a grant from the Kanagawa Prefectural Government of Japan and by AIST government subsidies.

The health status of healthy decontamination workers employed after the Fukushima nuclear disaster remains unclear. This study aimed to evaluate the prevalence of non-communicable diseases among such workers. In this observational study, questionnaires on lifestyle and social factors were administered as part of a health promotion program for decontamination workers in 2016 in Minamisoma City, Fukushima. The questionnaires and health check-up results were compared with those of the 2016 National Health and Nutrition Examination Survey (NHANES) in Japan. Overall, 123 male decontamination workers were enrolled; 93 (75.6%) were drinkers, and 84 (68.3%) were current smokers. The age-adjusted prevalence (95% confidence interval) of hypertension, dyslipidemia, diabetes mellitus, and obesity were 27.2% (20.1–34.4%), 30.4% (22.6–38.2%), 11.3% (5.5–17.1%), and 49.0% (39.0–58.9%), respectively. The age-adjusted prevalence in the NHANES were 32.8% (31.1–34.5%), 16.1% (14.5–17.6%), 7.0% (6.2–7.7%), and 31.2% (29.9–32.5%), respectively. The prevalence of obesity, dyslipidemia, binge drinking, and smoking were higher in healthy male decontamination workers than in the general population. Decontamination workers in disaster-struck areas may have higher risks of developing non-communicable diseases, possibly due to their original health status. Continuous monitoring of their health status and proper interventions are warranted.

After the Fukushima accident, airborne monitoring was implemented to measure airborne radiation. We examined the relationships between airborne and individual radiation monitoring and clarified the use of airborne monitoring to evaluate the effects of decontamination on residents’ received doses. We used the air dose rate data from four airborne monitors conducted between 2013 and 2016, and the dose data from four individual monitors (in which a total of 18 392 adults and 3650 children participated), conducted in Minamisoma City during the same period. We examined the Pearson correlation coefficients between the airborne and individual monitoring data and estimated exposure ratios (ERs; ratios of individual dose to air dose rates) among adults and children. We also estimated the effects of decontamination on residents’ doses based on airborne monitoring data, adjusting this for timing and dosing through propensity score matching, which were then compared to individual monitoring data. There were significant correlations between airborne and individual monitoring doses among adults and children, and more than 80% of residents showed a good estimation–observation agreement within a factor of two. The median of ERs was 0.304 and 0.250 among adults and children, respectively. There was a significant difference between the two. Effects of decontamination on residents’ doses estimated from airborne monitoring were significantly lower than those estimated from individual monitoring. These findings suggest that airborne monitoring can be used to estimate representative radiation doses within residential areas. It may be a useful tool for enhancing communication among stakeholders and supporting individual and policy decisions; however, it is less sensitive for evaluating individual effects of decontamination than individual monitoring. Combined use of airborne and individual monitoring also showed a lower median of ERs in children than in adults and in a Japanese government’s model, possibly due to prioritised decontamination for children and differences between their behavioral patterns.

Many studies have consistently reported the bidirectional relationship between problem drinking and psychological distress following a disaster, but the risk factors of problem drinking following a disaster remain unclear. In this study, we therefore aimed to explore the risk factors associated with the incidence of problem drinking among evacuees after the Great East Japan Earthquake of March 11, 2011. We used the data for evacuees of the Fukushima Daiichi nuclear power plant accident, obtained from the Mental Health and Lifestyle Survey. A total of 12,490 individuals from 13 municipalities, which included the evacuation order areas after the accident, completed surveys between 2012 and 2013. The CAGE (Cutting down, Annoyed by criticism, Guilty feeling, and Eye-opener) questionnaire was used to screen the participants for alcohol dependence, and a score ≥ 2 indicated problem drinking. Logistic regression models were applied to investigate the possible predictors of problem drinking. The results showed that insufficient sleep and heavy drinking (≥ 4 drinks per day) were significant risk factors for the incidence of problem drinking in both men and women. Additional risk factors included family financial issues due to the disaster and trauma symptoms among men and a diagnosed history of mental illness among women. Other remaining variables were not significantly associated with problem drinking. The present study is the first to identify the risk factors for problem drinking following a compound disaster. Our findings could be used to develop a primary intervention program to improve evacuees' health and lives following a disaster.

After the Fukushima nuclear accident in 2011, there was confusion among the public caused by uncoordinated information about radiation provided by diverse channels. We explored the association between information sources regarding reconstruction progress after the disaster and mental fatigue in Fukushima. We used data from the annual public opinion survey by the Fukushima Prefectural Government on its policies from 2013 to 2015, which contained survey responses from 1,300 community residents randomly selected from the 28 municipalities in the Fukushima Prefecture. The survey contained a question assessing mental fatigue: "How often do you usually feel mentally tired or depressed?" In total, 2,130 participants (758 participants in 2013, 699 participants in 2014, and 673 participants in 2015) were analyzed. The respondents were classified as two categories, "high mental fatigue" and "low mental fatigue," based on their responses to this question. Overall, the proportion of participants with high mental fatigue was 13.2%. There was no association between the year of survey or occupation and high mental fatigue. Cluster analysis was performed to classify information sources. Then, we conducted a cross-sectional analysis of the associations between clusters of information sources and high mental fatigue. We found that unreliable information sources, such as "Internet" and "a combination of TV, radio, and word of mouth," were significantly associated with high mental fatigue, compared with reliable information sources, such as "municipal public relations in addition to major media (newspaper, TV, and radio)." These findings provide important insights into how information sources affect mental fatigue following a disaster.

We developed an environmental exposure model to estimate the coronavirus disease 2019 (COVID-19) risk among participants at outdoor music festivals and validated the model using two real events—one in Japan (Event 1) and one in Spain (Event 2). Furthermore, we considered a hypothetical situation in which Event 1 was held but enhanced measures were implemented to evaluate the extent to which the risk could be reduced by additional infection control measures, such as negative antigen tests on the day of the event, wearing of masks, disinfection of environmental surfaces, and vaccination. Among 7,392 participants, the total number of already- and newly-infected individuals who participated in Event 1 according to the new model was 47.0 (95% uncertainty interval: 12.5–185.5), which is in good agreement with the reported value (45). The risk of infection at Event 2 (1.98 × 10−2; 95% uncertainty interval: 0.55 × 10−2–6.39 × 10−2), calculated by the model in this study, was also similar to the estimated value in the previous epidemiological study (1.25 × 10−2). These results for the two events in different countries highlighted the validity of the model. Among the additional control measures in the hypothetical Event 1, vaccination, mask-wearing, and disinfection of surfaces were determined to be effective. Based on the combination of all measures, a 94% risk reduction could be achieved. In addition to setting a benchmark for an acceptable number of newly-infected individuals at the time of an event, the application of this model will enable us to determine whether it is necessary to implement additional measures, limit the number of participants, or refrain from holding an event.

There is a need to evaluate and minimize the risk of novel coronavirus infections at mass gathering events, such as sports. In particular, to consider how to hold mass gathering events, it is important to clarify how the local infection prevalence, the number of spectators, the capacity proportion, and the implementation of preventions affect the infection risk. In this study, we used an environmental exposure model to analyze the relationship between infection risk and infection prevalence, the number of spectators, and the capacity proportion at mass gathering events in football and baseball games. In addition to assessing risk reduction through the implementation of various preventive measures, we assessed how face-mask-wearing proportion affects infection risk. Furthermore, the model was applied to estimate the number of infectors who entered the stadium and the number of newly infected individuals, and to compare them with actual reported cases. The model analysis revealed an 86-95% reduction in the infection risk due to the implementation of face-mask wearing and hand washing. Under conditions in which vaccine effectiveness was 20% and 80%, the risk reduction rates of infection among vaccinated spectators were 36% and 96%, respectively. Among the individual measures, face-mask wearing was particularly effective, and the infection risk increased as the face-mask-wearing proportion decreased. A linear relationship was observed between infection risk at mass gathering events and the infection prevalence. Furthermore, the number of newly infected individuals was also dependent on the number of spectators and the capacity proportion independent of the infection prevalence, confirming the importance of considering spectator capacity in infection risk management. These results highlight that it is beneficial for organisers to ensure prevention compliance and to mitigate or limit the number of spectators according to the prevalence of local infection. Both the estimated and reported numbers of newly infected individuals after the events were small, below 10 per 3-4 million spectators, despite a small gap between these numbers.

The purpose of this study was to identify the needs of stakeholders in developing a mobile application (MP) to be used by returning residents and providers of healthcare and medical/social services. The needs assessment of the residents revealed that among the elderly, ownership of smartphones and tablets was low and they were less likely to use the applications themselves.