Amina Sugimoto

Mortality Risk amongst Nursing Home Residents Evacuated after the Fukushima Nuclear Accident: A Retrospective Cohort Study

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 evacuations 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.

Limited Internal Radiation Exposure Associated with Resettlements to a Radiation-Contaminated Homeland after the Fukushima Daiichi Nuclear Disaster

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.

The Relationship between Media Consumption and Health-Related Anxieties after the Fukushima Daiichi Nuclear Disaster

Background The Fukushima Daiichi nuclear disaster caused a global panic by a release of harmful radionuclides. In a disaster setting, misusage of contemporary media sources available today can lead to disseminated incorrect information and panic. The study aims to build a scale which examines associations between media and individual anxieties, and to propose effective media usages for future disaster management. Methods The University of Tokyo collaborated with the Fukushima local government to conduct a radiation-health-seminar for a total of 1560 residents, at 12 different locations in Fukushima. A 13 item questionnaire collected once before and after a radiation-seminar was used on factor analysis to develop sub-scales for multiple regression models, to determine relationships between the sub-scales and media type consumed. A paired t–test was used to examine any changes in sub-scale of pre- and post-seminar scores. Results Three sub-scales were revealed and were associated with different media types: was with rumors, while concern for the future was positively associated with regional-newspapers and negatively with national-newspapers. Anxiety about social-disruption was associated with radio. The seminar had a significant effect on anxiety reduction for all the three sub-scales. Conclusion Different media types were associated with various heightened concerns, and that a radiation seminar was helpful to reduce anxieties in the post-disaster setting. By tailoring post-disaster messages via specific media types, i.e., radio, it may be possible to effectively convey important information, as well as to calm fears about particular elements of post-disaster recovery and to combat rumors.

Absence of Internal Radiation Contamination by Radioactive Cesium among Children Affected by the Fukushima Daiichi Nuclear Power Plant Disaster.

AbstractChronic internal radiation contamination accounts for a substantial fraction of long-term cumulative radiation exposure among residents in radiation-contaminated areas. However, little information is available on ongoing chronic internal radiation contamination among residents near the crippled Fukushima Daiichi nuclear power plant. Using a whole body counter, internal radiation contamination levels among elementary and middle school students who commute to 22 schools located within Minamisoma city were assessed between May and July 2013 (26 to 28 mo after the disaster). Of 3,299 elementary and middle school students in the city, 3,255 individuals (98%) were screened through school health check-ups. Not a single student was detected with internal radiation contamination due to radioactive cesium. The study found no risk of chronic internal radiation exposure among residents near the crippled nuclear power plant. Current food inspection by local governments, volunteers, and farmers has been functioning well within Fukushima prefecture. However, food management by screening suspected contamination along with whole body counter screening are key public health interventions and should be continued to avoid further internal radiation exposure in radiation-contaminated areas.

Assessment of the Risk of Medium-Term Internal Contamination in Minamisoma City, Fukushima, Japan, after the Fukushima Dai-ichi Nuclear Accident

Background: The Fukushima Dai-ichi nuclear disaster, the first level-7 major nuclear disaster since Chernobyl, raised concerns about the future health consequences of exposure to and intake of radionuclides. Factors determining the risk and level of internal radiation contamination after a nuclear accident, which are a key to understanding and improving current nuclear disaster management, are not well studied. Objective: We investigated both the prevalence and level of internal contamination in residents of Minamisoma, and identified factors determining the risk and levels of contamination. Methods: We implemented a program assessing internal radiation contamination using a whole body counter (WBC) measurement and a questionnaire survey in Minamisoma, between October 2011 and March 2012. Results: Approximately 20% of the city’s population (8,829 individuals) participated in the WBC measurement for internal contamination, of which 94% responded to the questionnaire. The proportion of participants with detectable internal contamination was 40% in adults and 9% in children. The level of internal contamination ranged from 2.3 to 196.5 Bq/kg (median, 11.3 Bq/kg). Tobit regression analysis identified two main risk factors: more time spent outdoors, and intake of potentially contaminated foods and water. Conclusions: Our findings suggest that, with sensible and reasonable precautions, people may be able to live continuously in radiation-affected areas with limited contamination risk. To enable this, nuclear disaster response should strictly enforce food and water controls and disseminate evidence-based and up-to-date information about avoidable contamination risks. Citation: Sugimoto A, Gilmour S, Tsubokura M, Nomura S, Kami M, Oikawa T, Kanazawa Y, Shibuya K. 2014. Assessment of the risk of medium-term internal contamination in Minamisoma City, Fukushima, Japan, after the Fukushima Dai-ichi Nuclear accident. Environ Health Perspect 122:587–593; http://dx.doi.org/10.1289/ehp.1306848

The Immediate Physical and Mental Health Crisis in Residents Proximal to the Evacuation Zone After Japan's Nuclear Disaster: An Observational Pilot Study

OBJECTIVE The 2011 earthquake and Fukushima nuclear disaster in Japan have had devastating effects on residents near the damaged nuclear power plant, but quantifying its effect on their health has been difficult. METHODS Among the 564 residents of Iitate Village and Soma City who enrolled in this study, we evaluated the changes of clinical parameters in 155 participants who underwent annual health evaluations in the previous year and after the earthquake. Psychological distress was also measured by using patient health questionnaire 9 (PHQ-9). RESULTS Participants (median age, 64 years) showed significant post-disaster increases in body weight, body mass index, systolic and diastolic blood pressure, blood glucose levels, and triglyceride levels. PHQ-9 scores of 10 or greater were found in 12% of the subjects, indicating that a substantial number had major depression. CONCLUSIONS The findings in this study showed substantial deterioration in clinical parameters related to lifestyle diseases and the presence of general psychological distress among residents living near the damaged nuclear power plant after the Fukushima Daiichi disaster. In addition to controlling the levels of radiation exposure, aggressive management of immediate physical and mental health crisis for residents may be necessary in future nuclear accidents.

Measurement of internal radiation exposure among decontamination workers in villages near the crippled Fukushima Daiichi Nuclear Power Plant.

AbstractDecontamination workers may face a high risk of exposure to internal irradiation through inhalation during decontamination activities; there is, however, little previous research on the levels of internal contamination during decontamination procedures. The authors reviewed the medical records, including whole body counter measurements, of decontamination workers in villages near the crippled Fukushima Daiichi Nuclear Power Plant to assess their levels of internal radiation exposure. In total, 83 decontamination workers were enrolled in this study. They were regularly engaged in decontamination activities in highly contaminated areas where surface 137Cs deposition density was over 100 kBq m−2. The present study showed low levels of internal exposure among the decontamination workers near the Fukushima Daiichi nuclear plant. The cesium burdens of all the decontamination workers were below detection limits. They had reported no acute health problems. The resuspension of radioactive materials may cause minimal internal contamination during decontamination activities.

Increased incidence of dog-bite injuries after the Fukushima nuclear accident.

OBJECTIVE The objective of this study is to assess the localized incidence of dog bites following the nuclear accident related to the Great East Japan Earthquake in March 2011. METHODS We identified the patients with dog bites in our hospital in Minamisoma City, Fukushima, during the period from 1year prior to the earthquake to 3.5months following it, and calculated the monthly and weekly incidence proportions by dividing the patient number by the total emergency room visits. We also analyzed the data by the characteristics of the patients. RESULTS We identified 27 dog-bite cases during the post-disaster period. The median monthly incidence proportion during the pre-disaster period and the highest monthly incidence proportion during the post-disaster period were 0.21 and 6.50 per 100 visits, respectively. The weekly incidence proportion peaked at 3weeks after the earthquake and thereafter decreased to the baseline level. CONCLUSION The Fukushima nuclear accident may be associated with an increased incidence of dog bites, and the prolonged evacuation in response to the radiation contamination may have prolonged the increased incidence after the disaster. Physicians and local residents should recognize this potential hazard. Countermeasures to contend with this risk should be a mandatory aspect of disaster preparedness, including for nuclear accidents.

Living in Contaminated Radioactive Areas Is Not an Acute Risk Factor for Noncommunicable Disease Development: A Retrospective Observational Study.

OBJECTIVE Although much attention is now being paid to the health risks associated with nuclear disasters, reliable information is lacking. We retrospectively evaluated the health effects of living in highly contaminated radioactive areas in Japan. METHODS The health evaluation was conducted in Tamano district, Fukushima prefecture, in 2011 and 2012. The surface deposition density of cesium in Tamano was 600 to 1000 kBq/m2 shortly after the Fukushima nuclear accident. Clinical parameters included body mass index, blood pressure, and laboratory examinations for blood cell counts, glucose levels, and lipid profiles. A screening program for internal and external exposure was also implemented. RESULTS One hundred fifty-five residents participated in the health evaluation. Significant decreases in average body mass index and blood pressure were observed from 2011 to 2012. Annual internal exposure levels did not exceeded 1 mSv in any participants. The levels of external exposure ranged from 1.3 to 4.3 mSv/y measured in the first test period but decreased to 0.8 to 3.6 mSv/y in the second test period. CONCLUSIONS These findings suggest that inhabiting nuclear contaminated areas is not always associated with short-term health deterioration and that radiation exposure can be controlled within safety limitations.