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Abstract Background The Great East Japan Earthquake and the subsequent Fukushima nuclear power plant accident in 2011 posed significant challenges to the educational sector, particularly affecting nursing students in the disaster area. However, to the best of our knowledge, there are no reports on the effects of the natural disaster coupled with the nuclear accident on the nursing students. Therefore, this study aimed to determine the impact of the Fukushima disasters on rate of academic failure events in nursing education. Methods A retrospective cohort approach was conducted, focusing on 677 students from Soma Nursing School admitted between 2001 and 2017. Four failure events—failure to pass the national examination, student retention, suspension, and withdrawal from school—were compared between three time periods: pre-disaster, early peri-disaster, and later peri-disaster. This analysis was followed by a questionnaire survey among the students and an interview with faculty members to gain further insights. Results Of the student cohort, 17% had at least one failure event. Students in the later peri-disaster phase faced an elevated failure rate at 29%. Variables such as being male, admission during later peri-disaster period, and local pre-admission residence played a significant role in these failure events in multivariate logistic regression analysis (adjusted odds ratio [95% confidence interval, p value]; 2.63 [1.49–4.64,

BackgroundPolicies, such as stay home, bubbling, and stay with your community, recommending that individuals reduce contact with diverse communities, including families and schools, have been introduced to mitigate the spread of the COVID-19 pandemic. However, these policies are violated if individuals from various communities gather, which is a latent risk in a real society where people move among various unreported communities. ObjectiveWe aimed to create a physical index to assess the possibility of contact between individuals from diverse communities, which serves as an indicator of the potential risk of SARS-CoV-2 spread when considered and combined with existing indices. MethodsMoving direction entropy (MDE), which quantifies the diversity of moving directions of individuals in each local region, is proposed as an index to evaluate a region’s risk of contact of individuals from diverse communities. MDE was computed for each inland municipality in Tokyo using mobility data collected from smartphones before and during the COVID-19 pandemic. To validate the hypothesis that the impact of intercommunity contact on infection expansion becomes larger for a virus with larger infectivity, we compared the correlations of the expansion of infectious diseases with indices, including MDE and the densities of supermarkets, restaurants, etc. In addition, we analyzed the temporal changes in MDE in municipalities. ResultsThis study had 4 important findings. First, the MDE values for local regions showed significant invariance between different periods according to the Spearman rank correlation coefficient (>0.9). Second, MDE was found to correlate with the rate of infection cases of COVID-19 among local populations in 53 inland regions (average of 0.76 during the period of expansion). The density of restaurants had a similar correlation with COVID-19. The correlation between MDE and the rate of infection was smaller for influenza than for COVID-19, and tended to be even smaller for sexually transmitted diseases (order of infectivity). These findings support the hypothesis. Third, the spread of COVID-19 was accelerated in regions with high-rank MDE values compared to those with high-rank restaurant densities during and after the period of the governmental declaration of emergency (P

Background: Telemedicine with video communication has become commonly applied during and after the COVID-19 pandemic. While audio-only encounters are not allowed in Japan after August 2023. The Centers for Medicaid and Medicare Services (CMS) in the United States revised the telehealth policy to make the video visit standard. We present here a case with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and diagnosed her with the Herpes zoster at audio-only encounters followed by an in-person clinic visit. Case Presentation: A 31-year-old woman called our hospital for a complaint of right chest discomfort and a tingling sensation. The SARS-CoV-2 infection was confirmed on her with the polymerase chain reaction (PCR) test 4 days before the symptom onset. A telephone encounter was made for her since the video communication failed to be prepared. The attending physician made a diagnosis of herpes zoster based on her verbal explanation of symptoms and localized skin lesions. An anti-viral medication with amenamevir was given. The photos of skin lesions were sent 3 days after the audio visit, which was consistent with herpes zoster. The patient visited our outpatient clinic and was confirmed for herpes zoster serologically with positive antibodies of both varicella-zoster IgM and IgG. Conclusions: The audio-only visit could help diagnose herpes zoster if the follow-up examinations are performed adequately. Audio-only encounters preserve the flexibility of telemedicine when video communication cannot be prepared promptly.

ABSTRACTBackground Iron deficiency (ID) and iron deficiency anemia (IDA) are long-standing health problems in athletes, affecting both performance and health. ID prevalence in young athletes remains high and a matter of concern. ID and IDA can lead to fatigue, reduced endurance, and decreased oxygen transport, potentially compromising athletic performance. We hypothesized that ID would still be a major health concern in university athletes across sports clubs in Japan.Purpose The study aimed to investigate the prevalence of ID and IDA in athletes participating in Kendo, badminton, baseball, and handball at the University of Tsukuba (Tsukuba, Ibaraki Prefecture, Japan). The study also examined the correlation between hypoferritinemia and other variables, such as previous use of iron supplements, body mass index (BMI), energy intake, and years of athletics.Methods Between January and December 2019, 126 university athletes, consisting of 79 males and 47 females, underwent physical measurements and blood tests. The blood test included complete blood count, levels of serum ferritin, serum iron, and total iron-binding capacity. The anemia was defined in accordance with the WHO criteria. Daily energy and iron intake were estimated with the food frequency questionnaire in Japanese (FFQg). Thirty-four female athletes responded to a survey about their menstruation and low-dose estrogen-progestin (LEP) usage.Results While none of the athletes had anemia, 22 (47%) female athletes exhibited serum ferritin levels of 30 ng/mL or less, defining them as hypoferritinemia. The multivariate logistic regression model revealed that a shorter duration of the athletic experience (adjusted odd ratio [95% confidence interval]: 0.62 [0.43–0.90]), lower energy intake (0.994 [0.989–0.999]), and higher dietary iron intake (4.40 [1.12–17.26]) were associated with hypoferritinemia. Seventeen (50%) female athletes reported a decline in subjective performance during menstruation, albeit two took LEP regularly.Conclusions This study reveals that ID is a prevalent health concern among young female athletes across sports clubs. It underscores the need for their education on the importance of assessing ID status. Limitation includes the nature of single-site and observational study, the absence of hepcidin measurement, and an unspecified amount of exercise. Comprehensive investigations are needed to elucidate the causes and optimal treatments for ID in young athletes.

Abstract The present study aimed to clarify the characteristics of young evacuees who had missed the Comprehensive Health Check of the Fukushima Health Management Survey (FHMS) after the Great East Japan Earthquake in 2011. The FHMS has been conducted as a prospective cohort study to evaluate the health status of evacuees annually after the great earthquake in 2011. This study focused on the annual participation rate in the Comprehensive Health Check of evacuees aged between 20 and 37 years in 2011 who evacuated due to the Fukushima Daiichi Nuclear Power Plant accident. The characteristics of subjects who did not participate after the second survey year were identified with a multivariate logistic regression model. The participation rate was estimated at 26.6% (9720 among 36,502 residents) and 15.6% (5691 residents) in 2011 and 2012, respectively. The logistic regression model revealed the following characteristics at baseline as independent predictors of non-participation after the second year of the survey: age ≤ 24 years (adjusted odds ratio 2.11, 95% CI 1.84–2.42), 25–29 years of age (1.28, 1.13–1.45), men (1.52, 1.38–1.69), evacuation outside the municipality but within Fukushima prefecture (1.54, 1.40–1.70), evacuation outside the Fukushima prefecture (1.40, 1.21–1.63), anemia (1.23, 1.06–1.43), smoking habit (1.34, 1.21–1.48), and drinking habit (1.20, 1.09–1.32). A medical history of heart disease showed opposite odds ratios, which indicate the association with continuous participation (0.43, 0.26–0.72, respectively). We observed deteriorated participation in the prospective study of the Comprehensive Health Check of the FHMS among evacuees of a younger age group, men, those evacuated outside their municipalities, and those with history of anemia, smoking and drinking habits. Hence, the cohort study may have missed certain population groups with worse health behaviors. Thus, it is necessary to consider various measures to increase the participation rate in the disaster cohort study to understand the long-term health effects of disasters on younger residents in evacuation zones.

Abstract This study aimed to evaluate the sequential changes in the proportion of anemia among young women over eight years after the Great East Japan Earthquake in 2011 using a prospective study of the Fukushima Health Management Survey. This study focused on the women aged between 20 and 44 who lived in the evacuation area of the nuclear power plant accident. The yearly age-adjusted proportion of anemia was accessed with data between July 2011 and March 2019. A total of 9,198 women participated in the health checkup in 2011, albeit the participation was decreased to 1,241 in 2018. The age-adjusted proportion of anemia was 16.7% in 2012 and then declined after 2013 (p with Cochran-Armitage trend test = 0.03). The multivariate regression analysis identified

Influenza vaccination is necessary to reduce severe influenza complications, especially in immunocompromised people such as cancer patients. However, few studies have examined influenza vaccination uptake among adult Japanese patients with cancer; their attitudes toward vaccination, as well as factors related to vaccine hesitancy, are unclear. From September 1 to October 31, 2020, we disseminated a web-based questionnaire to patients with a history of cancer via snowball sampling through e-mails and social media of two Japanese cancer patients associations. A total of 163 surveys were completed. One hundred (61.3%) participants received an influenza vaccination in the 2019/2020 season, and the main reasons for vaccination were as follows: recommendation by medical professionals, positive awareness of vaccination through books or the internet, and provision of vaccination in the workplace. The main reasons for not receiving a vaccination were fear of adverse events, lack of concern about influenza infection, and lack of trust in vaccine effectiveness. In terms of the 2020/2021 season, 120 participants (73.6%) reported their intention to receive an influenza vaccination. Multiple regression analysis showed that significant factors for positive intention were the the treatment without chemotherapy (p = .009), vaccination history in the 2019/2020 season (p

Abstract Restriction on hospital visits for COVID‐19 infection control continues to have a significant negative impact on patients and their families. For a patient receiving palliative care, this social isolation may deteriorate their mental health. In such situations, home care could be a viable solution to this problem.

Abstract Home care can present many challenges without management. During COVID‐19 pandemic, when an informal caregiver becomes infected and had to isolate themselves, finding another caregiver becomes extremely challenging. For terminally ill patients, who relies on other for even minor tasks, interruption of care could pose severe negative consequences.

Booster vaccination reduces the incidence of severe cases and mortality related to COVID-19, with cellular immunity playing an important role. However, little is known about the proportion of the population that has achieved cellular immunity after booster vaccination. Thus, we conducted a Fukushima cohort database and assessed humoral and cellular immunity in 2526 residents and healthcare workers in Fukushima Prefecture in Japan through continuous blood collection every 3 months from September 2021. We identified the proportion of people with induced cellular immunity after booster vaccination using the T-SPOT.COVID test, and analyzed their background characteristics. Among 1089 participants, 64.3% (700/1089) had reactive cellular immunity after booster vaccination. Multivariable analysis revealed the following independent predictors of reactive cellular immunity: age < 40 years (adjusted odds ratio: 1.81; 95% confidence interval: 1.19–2.75; p-value: 0.005) and adverse reactions after vaccination (1.92, 1.19–3.09, 0.007). Notably, despite IgG(S) and neutralizing antibody titers of ≥500 AU/mL, 33.9% (349/1031) and 33.5% (341/1017) of participants, respectively, did not have reactive cellular immunity. In summary, this is the first study to evaluate cellular immunity at the population level after booster vaccination using the T-SPOT.COVID test, albeit with several limitations. Future studies will need to evaluate previously infected subjects and their T-cell subsets.

Background Anemia is a common health issue among adolescents. Anemic conditions could affect physical performance; however, the actual profiles of anemia in adolescent students in sports clubs have not been well documented. Methods We conducted a retrospective chart review of individuals aged 13–22 years who belonged to sports clubs in schools and visited an outpatient clinic between August 1, 2016, and August 31, 2020. The medical and laboratory records, including serum levels of ferritin, folate, vitamin B12, and creatinine kinase at their first visit were assessed. Results A total of 485 individuals (231 male (48%) and 254 female (52%) patients) were eligible for the study. The most common club activity was track and field (n = 171 (35%)). The overall prevalence of the World Health Organization-defined anemia was 16.5% (95% CI [13.1–20.4]; 9.0% [5.4–13.8] and 23.1% [17.8–29.2] in males and females, respectively) after excluding pre-treated individuals. Hypoferritinemia and elevation of serum creatinine kinase levels were identified as independent contributors to anemia in both sexes (odds ratios: 13.2 (95% CI [4.2–41.1]), p < 0.001 and 14.7 (95% CI [1.8–118.4]), p = 0.012, respectively for males; odds ratios: 6.6 (95% CI [1.3–13.9]), p < 0.001 and 2.7 (95% CI [1.4–5.5]), p = 0.004, respectively for females). Discussion Anemia is prevalent in both male and female adolescent students in sports clubs. Iron deficiency and excessive training indicated by elevated creatinine kinase levels may contribute to the risk of anemia. Physicians should assess the amount of exercise, and not merely iron storage, in clinical practice.

Anisakiasis is a parasitic disease caused by Anisakis simplex and has become an emerging zoonosis as preferences for eating raw or undercooked seafood have become more common. Few case reports of asymptomatic anisakiasis have been published to date. A 79-year-old asymptomatic man underwent esophagogastroduodenoscopy (EGD) for gastric cancer screening. The gastroenterologist diagnosed superficial gastritis without any malignant lesions but found an Anisakis larva while reviewing EGD images. The physician performed a second EGD and removed the larva. The patient reported that he ate the flatfish sashimi for dinner on the day before the first EGD. This case indicates the existence of asymptomatic gastric anisakiasis, indicating that anisakiasis incidence may have previously been underestimated.

Vaccination is effective in preventing COVID-19-related hospitalization among all age groups, but there is limited evidence on the effectiveness of the booster of the SARS-CoV-2 vaccine among adolescents. We analyzed the data on the status of SARS-CoV-2 infection and their vaccination profiles in adolescents aged 13–18 years in Soma city (Fukushima, Japan) (n = 1835) from 14 May to 15 June 2022. The crude incidence rate and 95% confidence interval were calculated with the negative-binomial regression model after classifying the immunization status. The crude effectiveness of a booster administration to prevent infections was estimated as 86.4% (95% confidence interval: 57.2–95.7) when compared with the primary vaccination alone. The results of this study support that the community-based mass vaccination campaign of a booster dose among adolescents has additional protection from COVID-19 during the period of the B.1.1.529 (omicron) variant wave.

Background Iron deficiency is widely recognized as being the cause of anemia in athletes, although iron status in athletes of Kendo, a traditional Japanese martial art based on swordsmanship and practiced as an educational sport, has not been widely investigated. Methods We performed a health assessment on anemia and serum ferritin levels, along with nutrient intake evaluation, for Kendo practitioners in a university in Japan. Results A total of 56 Kendo practitioners (39 male and 17 female) aged between 18 and 23 years participated in the study. No individuals exhibited WHO-defined anemia (less than 13 or 12 g/dL of hemoglobin levels in male or female), while hypoferritinemia (less than 30 ng/mL) was found in seven (41%) females but not in males. Significantly higher body mass index was found in the female athletes with hypoferritinemia compared to females with normo-ferritinemia in sub-analysis (median [interquartile range]; 25.6 [24.2, 26.9] versus 22.6 [21.7, 24.1], respectively. p

COVID-19 vaccines are the most critical measure for controlling the COVID-19 pandemic; however, we have little information on their complications. We experienced a case of a patient who developed hyperthyroidism complicated with atrial fibrillation and heart failure on the sixth day after the first dose of COVID-19 vaccination. This case report shows the importance of considering hyperthyroidism as a possible complication after COVID-19 vaccination.

Abstract Background Little information is available concerning how patient delay may be affected by mass disasters. The main objectives of the present study are to identify whether there was a post-disaster increase in the risk of experiencing patient delay among breast cancer patients in an area affected by the 2011 triple disaster in Fukushima, Japan, and to elucidate factors associated with post-disaster patient delay. Sociodemographic factors (age, employment status, cohabitant status and evacuation status), health characteristics, and health access- and disaster-related factors were specifically considered. Methods Records of symptomatic breast cancer patients diagnosed from 2005 to 2016 were retrospectively reviewed to calculate risk ratios (RRs) for patient delay in every year post-disaster compared with the pre-disaster baseline. Total and excessive patient delays were respectively defined as three months or more and twelve months or more from symptom recognition to first medical consultation. Logistic regression analysis was conducted for pre- and post-disaster patient delay in order to reveal any factors potentially associated with patient delay, and changes after the disaster. Results Two hundred nineteen breast cancer patients (122 pre-disaster and 97 post-disaster) were included. After adjustments for age, significant post-disaster increases in RRs of experiencing both total (RR: 1.66, 95% Confidence Interval (CI): 1.02–2.70, p

Abstract Background Little is known about the effects of social isolation in the elderly on their process of gaining health information and seeking health care. Case presentation In March 2011, Fukushima, Japan experienced an earthquake, tsunami, and nuclear disaster, also known as Japan’s triple disaster. In June 2016, an 80-year-old Japanese man, who lived alone after divorce at the age of 42, presented to our hospital with bloody stools and dizziness. Although his bloody stools initially occurred in May 2015, a year earlier, he did not pursue the possibility of malignancy. He was diagnosed as having stage IIIA rectal cancer. Detailed history taking revealed that he experienced social isolation after the disaster, due to the evacuation of his friends, losing his regular opportunities for socialization. He additionally reported that the current diagnosis of rectal cancer made him feel he had lost his health in addition to his social relationships. Although radical surgery was attempted, it failed to resect the lesion completely, and thereafter his disease gradually progressed. As support from family or friends was not available, he was not able to receive palliative radiation therapy or home-based care in his end-of-life period. He died at a long-term care facility in February 2017. Conclusions This case suggests that intense social isolation after the Fukushima disaster was a likely contributor to the patient delay, poor treatment course, and poor outcome of an elderly patient with rectal cancer. Direct communication with family and friends may play an indispensable role in increasing health awareness and promoting health-seeking behaviors, and in the midst of social isolation, elderly patients with cancer may lose these opportunities and experience increased risk of patient delay. Although health care providers may be able to alleviate isolation-induced delay by promoting cancer knowledge and awareness widely among local residents, policy-led interventions at the community level may be essential to reducing social isolation and its health consequences.

Background The overall proportion of female physician is increasing worldwide. However, its ratio exhibits a substantial diversity among each member country of Organisation for Economic Co-operation and Development (OECD). This study aimed to reveal the social factors of countries associated with the percentage of female physicians. Methods We retrieved the percentage of female physicians and social characteristic which may affect the ratio of female physicians of 36 OECD countries in 2016 or nearest year from the World Bank Open Data. Multivariate regression analysis was performed after univariate evaluations with Spearman’s coefficient to explore correlation of social variables with the proportion of female physicians. Results The percentages of female adolescents who dropped out of school before lower secondary school, female population that attained or completed Master’s or equivalent degree, female labour force, and female academic staff in tertiary education showed statistically significant correlation with proportion of female physicians (Spearman coefficient = -0.527, 0.585, 0.501, and 0.499; P = .01, .001, .002, and .008). Female’s educational attainment at least Master’s or equivalent and that of female academic staff at tertiary education were selected after multivariate analysis. Conclusion Our study revealed the relationships between advanced education opportunity and female participation in academic positions with the percentage of female physicians. Our research is limited in the difficulty to evaluate physicians’ working hours in spite of its possible effect. Further studies with qualitative assessment are warranted to explore the detail reasons to cause gender gap in physician.

IntroductionDemographic changes as a result of evacuation in the acute phase of the 2011 Fukushima nuclear disaster are not well evaluated. We estimated post-disaster demographic transitions in Minamisoma City-located 14-38 km north of the nuclear plant-in the first month of the disaster; and identified demographic factors associated with the population remaining in the affected areas.Materials and methodsWe extracted data from the evacuation behavior survey administered to participants in the city between July 11, 2011 and April 30, 2013. Using mathematical models, we estimated the total population in the city after the disaster according to sex, age group, and administrative divisions of the city. To investigate factors associated with the population remaining in place after the disaster, a probit regression model was employed, taking into account sex, age, pre-disaster dwelling area, and household composition.ResultsThe overall population decline in Minamisoma City peaked 11 days after the disaster, when the population reached 7,107 people-11% of the pre-disaster level. The remaining population levels differed by area: 1.1% for mandatory evacuation zone, 12.5% for indoor sheltering zone, and 12.6% for other areas of the city. Based on multiple regression analyses, higher odds for remaining in place were observed among men (odds ratio 1.72 [95% confidence intervals 1.64-1.85]) than women; among people aged 40-64 years (1.40 [1.24-1.58]) than those aged 75 years or older; and among those living with the elderly, aged 70 years or older (1.18 [1.09-1.27]) or those living alone (1.71 [1.50-1.94]) than among those who were not.DiscussionDespite the evacuation order, some residents of mandatory evacuation zones remained in place, signaling the need for preparation to respond to their post-disaster needs. Indoor sheltering instructions may have accelerated voluntary evacuation, and this demonstrates the need for preventing potentially disorganized evacuation in future nuclear events.

Disaster has a negative impact on health conditions, especially on those of temporary housing residents. Health status has a close relationship with physical activity and performance. However, few reports have assessed physical performance among residents living in temporary housing. In this study, we compared physical capabilities between the elderly who evacuated to temporary housing and those who stayed in their own homes after the Great East Japan Earthquake. Subjects were recruited from those over 65 years of age who participated in the medical check-ups for temporary housing residents (TH group) or check-ups for residents of downtown areas (control group) in Soma City, Fukushima, in 2012. The subjects underwent grip strength, one-leg standing (OLS), and timed up and go tests (TUG). In total, 1890 participants were recruited. The TH group showed significantly stronger grip strength than that of the control group. On the other hand, the TH group showed weaker standing stability, according to decreased OLS and increased TUG scores. We revealed that standing stability was impaired among elderly temporary housing residents 1.5 years after the disaster. Disaster responders should take into account the health risks associated with living in temporary housing.

After the 2011 Fukushima Daiichi nuclear power plant accident, little information has been available on individual doses from external exposure among residents living in radioactively contaminated areas near the nuclear plant; in the present study we evaluated yearly changes in the doses from external exposure after the accident and the effects of decontamination on external exposure. This study considered all children less than 16 years of age in Soma City, Fukushima who participated in annual voluntary external exposure screening programs during the five years after the accident (n = 5,363). In total, 14,405 screening results were collected. The median participant age was eight years. The geometric mean levels of annual additional doses from external exposure attributable to the Fukushima accident, decreased each year: 0.60 mSv (range: not detectable (ND)-4.29 mSv), 0.37 mSv (range: ND-3.61 mSv), 0.22 mSv (range: ND-1.44 mSv), 0.20 mSv (range: ND-1.87 mSv), and 0.17 mSv (range: ND-0.85 mSv) in 2011, 2012, 2013, 2014, and 2015, respectively. The proportion of residents with annual additional doses from external exposure of more than 1 mSv dropped from 15.6% in 2011 to zero in 2015. Doses from external exposure decreased more rapidly than those estimated from only physical decay, even in areas without decontamination (which were halved in 395 days from November 15, 2011), presumably due to the weathering effects. While the ratios of geometric mean doses immediately after decontamination to before were slightly lower than those during the same time in areas without decontamination, annual additional doses reduced by decontamination were small (0.04-0.24 mSv in the year of immediately after decontamination was completed). The results of this study showed that the levels of external exposure among Soma residents less than 16 years of age decreased during the five years after the Fukushima Daiichi nuclear power plant accident. Decontamination had only limited and temporal effects on reducing individual external doses.

In 2011, Fukushima was struck by a triple disaster: an earthquake, tsunamis, and a nuclear accident. In the aftermath, there was much fear among hospital staff members about radiation exposure and many staff members failed to report to work.One objective is to measure this shortage in hospital staff and another is to compare the difference in recovery by hospital types and by categories of hospital staff.The monthly records of the number of staff members from May 2011 to September 2012 were extracted anonymously from the records of 7 local hospitals in the Soso district in Fukushima. Change in the number of staff was analyzed.Staff shortages at hospitals reached a maximum within one month after the disaster (47% reported to work). The shortage of clerks was the most severe (38% reported to work), followed by nurses (48% reported to work). The shortages remained even 18 months after the disaster.After a disaster in which the damage to hospital functions surpasses the structural damage, massive support of human resources in the acute phase and a smaller volume of support in the mid-term phase appear to be required, particularly for non-medical staff.

An assessment of the external and internal radiation exposure levels, which includes calculation of effective doses from chronic radiation exposure and assessment of long-term radiation-related health risks, has become mandatory for residents living near the nuclear power plant in Fukushima, Japan. Data for all primary and secondary children in Minamisoma who participated in both external and internal screening programs were employed to assess the annual additional effective dose acquired due to the Fukushima Daiichi nuclear power plant disaster. In total, 881 children took part in both internal and external radiation exposure screening programs between 1st April 2012 to 31st March 2013. The level of additional effective doses ranged from 0.025 to 3.49 mSv/year with the median of 0.70 mSv/year. While 99.7% of the children (n = 878) were not detected with internal contamination, 90.3% of the additional effective doses was the result of external radiation exposure. This finding is relatively consistent with the doses estimated by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The present study showed that the level of annual additional effective doses among children in Minamisoma has been low, even after the inter-individual differences were taken into account. The dose from internal radiation exposure was negligible presumably due to the success of contaminated food control.

After the 2011 accident at the Fukushima Daiichi nuclear power plant, nursing-home residents and staff were evacuated voluntarily from damaged areas to avoid radiation exposure. Unfortunately, the evacuation resulted in increased mortalities among nursing home residents. We assessed the risk trade-off between evacuation and radiation for 191 residents and 184 staff at three nursing homes by using the same detriment indicator, namely loss of life expectancy (LLE), under four scenarios, i.e. "rapid evacuation (in accordance with the actual situation; i.e. evacuation on 22 March)," "deliberate evacuation (i.e. evacuation on 20 June)," "20-mSv exposure," and "100-mSv exposure." The LLE from evacuation-related mortality among nursing home residents was assessed with survival probability data from nursing homes in the city of Minamisoma and the city of Soma. The LLE from radiation mortality was calculated from the estimated age-specific mortality rates from leukemia and all solid cancers based on the additional effective doses and the survival probabilities. The total LLE of residents due to evacuation-related risks in rapid evacuation was 11,000 persons-d-much higher than the total LLEs of residents and staff due to radiation in the other scenarios (27, 1100, and 5800 persons-d for deliberate evacuation, 20 mSv-exposure, and 100 mSv-exposure, respectively). The latitude for reducing evacuation risks among nursing home residents is surprisingly large. Evacuation regulation and planning should therefore be well balanced with the trade-offs against radiation risks. This is the first quantitative assessment of the risk trade-off between radiation exposure and evacuation after a nuclear power plant accident.

Maintaining low levels of chronic internal contamination among residents in radiation-contaminated areas after a nuclear disaster is a great public health concern. However, the efficacy of reduction measures for individual internal contamination remains unknown. To reduce high levels of internal radiation exposure in a group of individuals exposed through environmental sources, we performed careful dietary intervention with identification of suspected contaminated foods, as part of mass voluntary radiation contamination screenings and counseling program in Minamisoma Municipal General Hospital and Hirata Central Hospital. From a total of 30,622 study participants, only 9 residents displayed internal cesium-137 (Cs-137) levels of more than 50 Bq/kg. The median level of internal Cs-137 contamination in these residents at the initial screening was 4,830 Bq/body (range: 2,130-15,918 Bq/body) and 69.6 Bq/kg (range: 50.7-216.3 Bq/kg). All these residents with high levels of internal contamination consumed homegrown produce without radiation inspection, and often collected mushrooms in the wild or cultivated them on bed-logs in their homes. They were advised to consume distributed food mainly and to refrain from consuming potentially contaminated foods without radiation inspection and local produces under shipment restrictions such as mushrooms, mountain vegetables, and meat of wild life. A few months after the intervention, re-examination of Cs levels revealed remarkable reduction of internal contamination in all residents. Although the levels of internal radiation exposure appear to be minimal amongst most residents in Fukushima, a subset of the population, who unknowingly consumed highly contaminated foodstuffs, experienced high levels of internal contamination. There seem to be similarities in dietary preferences amongst residents with high internal contamination levels, and intervention based on pre- and post-test counseling and dietary advice from medical care providers about risky food intake appears to be a feasible option for changing residents' dietary practices, subsequently resulting in a reduction in Cs internal contamination levels.

Vaccination is a preventive measure against influenza that does not require placing restrictions on social activities. However, since the stockpile of vaccine that can be prepared before the arrival of an emerging pandemic strain is generally quite limited, one has to select priority target groups to which the first stockpile is distributed. In this paper, we study a simulation-based priority target selection method with the goal of enhancing the collective immunity of the whole population. To model the region in which the disease spreads, we consider an urban area composed of suburbs and central areas connected by a single commuter train line. Human activity is modelled following an agent-based approach. The degree to which collective immunity is enhanced is judged by the attack rate in unvaccinated people. The simulation results show that if students and office workers are given exclusive priority in the first three months, the attack rate can be reduced from [Formula: see text] in the baseline case down to 1-2%. In contrast, random vaccination only slightly reduces the attack rate. It should be noted that giving preference to active social groups does not mean sacrificing those at high risk, which corresponds to the elderly in our simulation model. Compared with the random administration of vaccine to all social groups, this design successfully reduces the attack rate across all age groups.

INTRODUCTION: The quantification of social media impacts on societal and political events is a difficult undertaking. The Japanese Society of Oriental Medicine started a signature-collecting campaign to oppose a medical policy of the Government Revitalization Unit to exclude a traditional Japanese medicine, "Kampo," from the public insurance system. The signature count showed a series of aberrant bursts from November 26 to 29, 2009. In the same interval, the number of messages on Twitter including the keywords "Signature" and "Kampo," increased abruptly. Moreover, the number of messages on an Internet forum that discussed the policy and called for signatures showed a train of spikes. METHODS AND FINDINGS: In order to estimate the contributions of social media, we developed a statistical model with state-space modeling framework that distinguishes the contributions of multiple social media in time-series of collected public opinions. We applied the model to the time-series of signature counts of the campaign and quantified contributions of two social media, i.e., Twitter and an Internet forum, by the estimation. We found that a considerable portion (78%) of the signatures was affected from either of the social media throughout the campaign and the Twitter effect (26%) was smaller than the Forum effect (52%) in total, although Twitter probably triggered the initial two bursts of signatures. Comparisons of the estimated profiles of the both effects suggested distinctions between the social media in terms of sustainable impact of messages or tweets. Twitter shows messages on various topics on a time-line; newer messages push out older ones. Twitter may diminish the impact of messages that are tweeted intermittently. CONCLUSIONS: The quantification of social media impacts is beneficial to better understand people's tendency and may promote developing strategies to engage public opinions effectively. Our proposed method is a promising tool to explore information hidden in social phenomena.

Resettlement to their radiation-contaminated hometown could be an option for people displaced at the time of a nuclear disaster; however, little information is available on the safety implications of these resettlement programs. Kawauchi village, located 12-30 km southwest of the Fukushima Daiichi nuclear power plant, was one of the 11 municipalities where mandatory evacuation was ordered by the central government. This village was also the first municipality to organize the return of the villagers. To assess the validity of the Kawauchi villagers' resettlement program, the levels of internal Cesium (Cs) exposures were comparatively measured in returnees, commuters, and non-returnees among the Kawauchi villagers using a whole body counter. Of 149 individuals, 5 villagers had traceable levels of Cs exposure; the median detected level was 333 Bq/body (range, 309-1050 Bq/kg), and 5.3 Bq/kg (range, 5.1-18.2 Bq/kg). Median annual effective doses of villagers with traceable Cs were 1.1 x 10(-2) mSv/y (range, 1.0 x 10(-2)-4.1 x 10(-2) mSv/y). Although returnees had higher chances of consuming locally produced vegetables, Cochran-Mantel-Haenszel test showed that their level of internal radiation exposure was not significantly higher than that in the other 2 groups (p=0.643). The present findings in Kawauchi village imply that it is possible to maintain internal radiation exposure at very low levels even in a highly radiation-contaminated region at the time of a nuclear disaster. Moreover, the risks for internal radiation exposure could be limited with a strict food control intervention after resettlement to the radiation-contaminated village. It is crucial to establish an adequate number of radio-contaminated testing sites within the village, to provide immediate test result feedback to the villagers, and to provide education regarding the importance of re-testing in reducing the risk of high internal radiation exposure.

BACKGROUND: Safety of evacuation is of paramount importance in disaster planning for elderly people; however, little effort has been made to investigate evacuation-related mortality risks. After the Fukushima Daiichi Nuclear Plant accident we conducted a retrospective cohort survival survey of elderly evacuees. METHODS: A total of 715 residents admitted to five nursing homes in Minamisoma city, Fukushima Prefecture in the five years before 11th March 2011 joined this retrospective cohort study. Demographic and clinical characteristics were drawn from facility medical records. Evacuation histories were tracked until the end of 2011. The evacuation's impact on mortality was assessed using mortality incidence density and hazard ratios in Cox proportional hazards regression. RESULTS: Overall relative mortality risk before and after the earthquake was 2.68 (95% CI: 2.04-3.49). There was a substantial variation in mortality risks across the facilities ranging from 0.77 (95% CI: 0.34-1.76) to 2.88 (95% CI: 1.74-4.76). No meaningful influence of evacuation distance on mortality was observed although the first evacuation from the original facility caused significantly higher mortality than subsequent evacuations, with a hazard ratio of 1.94 (95% CI: 1.07-3.49). CONCLUSION: High mortality, due to initial evacuation, suggests that evacuation of the elderly was not the best life-saving strategy for the Fukushima nuclear disaster. Careful consideration of the relative risks of radiation exposure and the risks and benefits of evacuation is essential. Facility-specific disaster response strategies, including in-site relief and care, may have a strong influence on survival. Where evacuation is necessary, careful planning and coordination with other nursing homes, evacuation sites and government disaster agencies is essential to reduce the risk of mortality.