論文 - 野村　周平

Towards a Long-Term Strategy for Voluntary-Based Internal Radiation Contamination Monitoring: Representativeness of the Monitoring Results in Fukushima, Japan.

Shuhei Nomura, Masaharu Tsubokura, Michio Murakami, Kyoko Ono, Yoshitaka Nishikawa, Tomoyoshi Oikawa

International journal of environmental research and public health 14 （ 6 ）  2017年06月

査読有り,  ISSN  1661-7827

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Following Japan's 2011 Fukushima nuclear incident, voluntary participation, rather than mandatory, was adopted as the default scenario for individual radiation monitoring. We evaluated the representativeness of the internal monitoring results from voluntary participants in Minamisoma City, which is located 10-40 km from the Fukushima nuclear plant. Of approximately 70,000 individuals who were residing in Minamisoma City before the incident, a total of 19,263 residents (aged ≥21 years) participated in the monitoring from 1 October 2011 to 31 March 2015. Based on regression projection techniques with the available data obtained from the voluntary participants, the modeled probabilities of radiocesium (Cs) detection in October 2011 for Cs-137 and Cs-134 were 66.9% and 52.9%, respectively, which declined dramatically within a year following the incident. The rate of decline had stagnated since mid-2012, and the probability was close to zero after mid-2014. Sufficient agreement between the modeled probabilities of Cs detection (for the whole population) versus the measured Cs levels (for voluntary participants) was observed, except for Cs-134 in October 2011, indicating that the voluntary monitoring participant group was a good representative sample. Our findings affirmed the clinical importance of voluntary-based monitoring as a screening and dose-assessment tool in a post-nuclear incident. Our study informs societal decision-making regarding the long-term maintenance of the monitoring program under the current low exposure levels.

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Breast cancer patient delay in Fukushima, Japan following the 2011 triple disaster: a long-term retrospective study.

Akihiko Ozaki, Shuhei Nomura, Claire Leppold, Masaharu Tsubokura, Tetsuya Tanimoto, Takeru Yokota, Shigehira Saji, Toyoaki Sawano, Manabu Tsukada, Tomohiro Morita, Sae Ochi, Shigeaki Kato, Masahiro Kami, Tsuyoshi Nemoto, Yukio Kanazawa, Hiromichi Ohira

BMC cancer （BIOMED CENTRAL LTD）  17 （ 1 ） 423 - 423 2017年06月

査読有り,  ISSN  1471-2407

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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 < 0.05) and excessive patient delay (RR: 4.49, 95% CI: 1.73-11.65, p < 0.01) were observed. The RRs for total patient delay peaked in the fourth year post-disaster, and significant increases in the risk of excessive patient delay were observed in the second, fourth, and fifth years post-disaster, with more than five times the risk observed pre-disaster. A family history of any cancer was the only factor significantly associated with total patient delay post-disaster (odds ratio: 0.38, 95% CI: 0.15-0.95, p < 0.05), while there were no variables associated with delay pre-disaster. CONCLUSIONS: The triple disaster in Fukushima appears to have led to an increased risk of patient delay among breast cancer patients, and this trend has continued for five years following the disaster.

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Birth Outcomes after the Fukushima Daiichi Nuclear Power Plant Disaster: A Long-Term Retrospective Study.

Claire Leppold, Shuhei Nomura, Toyoaki Sawano, Akihiko Ozaki, Masaharu Tsubokura, Sarah Hill, Yukio Kanazawa, Hiroshi Anbe

International journal of environmental research and public health 14 （ 5 ）  2017年05月

査読有り,  ISSN  1661-7827

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Changes in population birth outcomes, including increases in low birthweight or preterm births, have been documented after natural and manmade disasters. However, information is limited following the 2011 Fukushima Daiichi Nuclear Power Plant Disaster. In this study, we assessed whether there were long-term changes in birth outcomes post-disaster, compared to pre-disaster data, and whether residential area and food purchasing patterns, as proxy measurements of evacuation and radiation-related anxiety, were associated with post-disaster birth outcomes. Maternal and perinatal data were retrospectively collected for all live singleton births at a public hospital, located 23 km from the power plant, from 2008 to 2015. Proportions of low birthweight (<2500 g at birth) and preterm births (<37 weeks gestation at birth) were compared pre- and post-disaster, and regression models were conducted to assess for associations between these outcomes and evacuation and food avoidance. A total of 1101 live singleton births were included. There were no increased proportions of low birthweight or preterm births in any year after the disaster (merged post-disaster risk ratio of low birthweight birth: 0.98, 95% confidence interval (CI): 0.64-1.51; and preterm birth: 0.68, 95% CI: 0.38-1.21). No significant associations between birth outcomes and residential area or food purchasing patterns were identified, after adjustment for covariates. In conclusion, no changes in birth outcomes were found in this institution-based investigation after the Fukushima disaster. Further research is needed on the pathways that may exacerbate or reduce disaster effects on maternal and perinatal health.

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Towards a Long-Term Strategy for Voluntary-Based Internal Radiation Contamination Monitoring: A Population-Level Analysis of Monitoring Prevalence and Factors Associated with Monitoring Participation Behavior in Fukushima, Japan.

Shuhei Nomura, Masaharu Tsubokura, Akihiko Ozaki, Michio Murakami, Susan Hodgson, Marta Blangiardo, Yoshitaka Nishikawa, Tomohiro Morita, Tomoyoshi Oikawa

International journal of environmental research and public health 14 （ 4 ）  2017年04月

査読有り,  ISSN  1661-7827

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Following Japan's 2011 Fukushima nuclear incident, we assessed voluntary-based monitoring behavior in Minamisoma City-located 10-40 km from the Fukushima nuclear plant-to inform future monitoring strategies. The monitoring in Minamisoma included occasional free of charge internal-radiation-exposure measurements. Out of around 70,000 individuals residing in the city before the incident, a total of 45,788 residents (female: 52.1%) aged ≥21 were evaluated. The monitoring prevalence in 2011-2012 was only 30.2%, and this decreased to 17.9% in 2013-2014. Regression analyses were performed to estimate factors associated with the monitoring prevalence and participation behavior. The results show that, in comparison with the age cohort of 21-30 years, the cohort of 71-80 and ≥81 years demonstrated significantly lower monitoring prevalence; female residents had higher monitoring prevalence than male residents; those who were living in evacuation zones at the time of the incident had higher monitoring prevalence than those who lived outside any of the evacuation zones; for those living outside Fukushima and neighboring Prefectures post-incident monitoring prevalence decreased significantly in 2013-2014. Our findings inform the discussion on the concepts of radiation risk perception and accessibility to monitoring and societal decision-making regarding the maintenance of the monitoring program with low monitoring prevalence. We also stress the possibility that the monitoring can work both to check that internal contamination levels are within acceptable limits, and as a risk communication tool, alleviating individuals' concern and anxiety over radiation contamination.

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Additional risk of diabetes exceeds the increased risk of cancer caused by radiation exposure after the Fukushima disaster.

Michio Murakami, Masaharu Tsubokura, Kyoko Ono, Shuhei Nomura, Tomoyoshi Oikawa

PloS one （PUBLIC LIBRARY SCIENCE）  12 （ 9 ） e0185259 2017年

査読有り,  ISSN  1932-6203

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The 2011 Fukushima disaster led to increases in multiple risks (e.g., lifestyle diseases and radiation exposure) and fear among the public. Here, we assessed the additional risks of cancer caused by radiation and diabetes related to the disaster and the cost-effectiveness of countermeasures against these conditions. Our study included residents of the cities of Minamisoma and Soma (10-40 km and 35-50 km north of the Fukushima Daiichi (N° 1) Nuclear Power Station, respectively). We used the loss of life expectancy (LLE) as an indicator to compare risks between radiation exposure and diabetes. We also estimated the cost-effectiveness of radiation-related countermeasures, including restricted food distribution, decontamination, and whole-body counter tests and interventions. Metformin therapy was selected as a representative management for diabetes. The diabetes-related LLEs among residents were 4.1 (95% confidence interval: 1.4-6.8) ×10-2 years for the whole population and 8.0 (2.7-13.2) ×10-2 years for 40s to 70s in a scenario that considered the additional incidence of diabetes during the first 10 years. The cancer-related LLEs caused by lifetime exposure to radiation were 0.69 (2.5-97.5 percentile: 0.61-0.79) ×10-2 years for the whole population and 0.24 (0.20-0.29) ×10-2 years for 40s to 70s. The diabetes-related LLEs among residents in the above-mentioned scenario were 5.9-fold and 33-fold higher than those attributed to average radiation among the whole population and among the 40s to 70s age groups, respectively. The costs per life-years saved of the radiation countermeasures (i.e., restricted food distribution, decontamination, and whole-body counter tests and interventions) were >1 to >4 orders of magnitude higher than those of general heath checkups and conventional management for diabetes. Our findings indicate that countermeasures to mitigate diabetes are warranted. Policy-makers' and individuals' understanding of multiple risks after any disaster will be essential to saving the lives of victims.

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Degarelix treatment is compatible with diabetes and antithrombotic therapy in patients with prostate cancer.

Suguru Tokiwa, Hiroaki Shimmura, Shuhei Nomura, Ryota Watanabe, Minoru Kurita, Naoto Yoshida, Kaori Yamashita, Yoshitaka Nishikawa, Alexander Kouzmenko, Shigeaki Kato

Research and reports in urology 9   225 - 232 2017年

査読有り,  ISSN  2253-2447

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Introduction: Therapeutically induced androgen deficiency (AD) is a standard treatment for patients with prostate cancer, but it is often associated with various adverse effects (AEs) that may lead to discontinuation. Some AEs may depend on the patient's health condition, while others may be due to complications of the drug delivery method. Degarelix is a gonadotropin-releasing hormone (GnRH) antagonist widely used for the treatment of androgen-dependent prostate cancer. This study aimed to ascertain the following: 1) the compatibility of degarelix treatment with diabetes and 2) any specific causal associations of degarelix injections with increased blood clotting and antithrombotic therapy requirements. Patients and methods: The medical records of 162 patients with prostate cancer who had undergone degarelix treatment were retrospectively examined. The association of a medical history of diabetes and anticoagulant co-treatment with degarelix treatment discontinuation was analyzed statistically. Results: Rapid and significant decreases in prostate-specific antigen (PSA) levels during the course of degarelix treatment were detected for patients with prostate cancer regardless of clinical state. During the 27 months of treatment, 68 subjects (48%) ceased degarelix treatment, owing to several reasons, mainly financial issues. Among these subjects, 19 had diabetes, while 35 were treated with antithrombotics. Extensive statistical analysis indicated that there were no causal associations between degarelix treatment discontinuation and preexisting diabetes or antithrombotic therapy. Conclusion: Our study suggests that preexisting diabetes and antithrombotic therapy were not significant factors for the discontinuation of degarelix treatment in patients with prostate cancer.

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Individual external doses below the lowest reference level of 1 mSv per year five years after the 2011 Fukushima nuclear accident among all children in Soma City, Fukushima: A retrospective observational study.

Masaharu Tsubokura, Michio Murakami, Shuhei Nomura, Tomohiro Morita, Yoshitaka Nishikawa, Claire Leppold, Shigeaki Kato, Masahiro Kami

PloS one （PUBLIC LIBRARY SCIENCE）  12 （ 2 ） e0172305 2017年

査読有り,  ISSN  1932-6203

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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.

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Non-communicable diseases in decontamination workers in areas affected by the Fukushima nuclear disaster: a retrospective observational study.

Toyoaki Sawano, Masaharu Tsubokura, Akihiko Ozaki, Claire Leppold, Shuhei Nomura, Yuki Shimada, Sae Ochi, Manabu Tsukada, Tsuyoshi Nemoto, Shigeaki Kato, Yukio Kanazawa, Hiromichi Ohira

BMJ open 6 （ 12 ） e013885 2016年12月

査読有り,  ISSN  2044-6055

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OBJECTIVES: To assess the prevalence of non-communicable diseases (NCDs), and whether NCDs were treated or not, among hospitalised decontamination workers who moved to radio-contaminated areas after Japan's 2011 Fukushima Daiichi Nuclear Power Plant disaster. METHODS: We retrospectively extracted records of decontamination workers admitted to Minamisoma Municipal General Hospital between 1 June 2012 and 31 August 2015, from hospital records. We investigated the incidence of underlying NCDs such as hypertension, dyslipidaemia and diabetes among the decontamination workers, and their treatment status, in addition to the reasons for their hospital admission. RESULTS: A total of 113 decontamination workers were admitted to the hospital (112 male patients, median age of 54 years (age range: 18-69 years)). In terms of the demographics of underlying NCDs in this population, 57 of 72 hypertensive patients (79.2%), 37 of 45 dyslipidaemic patients (82.2%) and 18 of 27 hyperglycaemic patients (66.7%) had not been treated for their NCDs before admission to the hospital. CONCLUSIONS: A high burden of underlying NCDs was found in hospitalised decontamination workers in Fukushima. Managing underlying diseases such as hypertension, hyperlipidaemia and diabetes mellitus is essential among this population.

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Assessment of Nutritional Status of Iodine Through Urinary Iodine Screening Among Local Children and Adolescents After the Fukushima Daiichi Nuclear Power Plant Accident.

Masaharu Tsubokura, Shuhei Nomura, Hajime Watanobe, Yoshitaka Nishikawa, Chiaki Suzuki, Sae Ochi, Claire Leppold, Hirokatsu Kinoshita, Shigeaki Kato, Yasutoshi Saito

Thyroid : official journal of the American Thyroid Association 26 （ 12 ） 1778 - 1785 2016年12月

査読有り,  ISSN  1050-7256

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BACKGROUND: Iodine deficiency is an important modifier of the risk of thyroid cancer following irradiation. However, little information is available on the prevalence of iodine deficiency in Fukushima and its surroundings after the Fukushima Daiichi nuclear power plant accident that occurred in March 2011. METHODS: In order to assess urinary iodine concentrations (UIC) and the prevalence of iodine deficiency and to elucidate any associations between demographic characteristics and UIC levels among children and adolescents aged ≤18 years at the time of the accident in Fukushima Prefecture and its surroundings, the data on voluntary UIC testing conducted by Hirata Central Hospital, Fukushima, were evaluated. RESULTS: A total of 4410 children and adolescents with a median age of 10 years at examination underwent UIC testing between October 2012 and October 2015. Calculated for all the participants, the median UIC level was 204 μg/L (range 25-21,100 μg/L). There were 133 (3.0%), 732 (16.6%), and 1472 (33.4%) participants with UIC levels of <50, <100, or ≥300 μg/L, respectively. Based on the World Health Organization criteria for nutritional iodine status, no participants were severely iodine deficient (<20 μg/L), but 16.6% of the population were mildly (50-100 μg/L) or moderately (20-50 μg/L) iodine deficient. While no significant difference in UIC was noted between those who did and did not increase dietary iodine intake after the accident (p = 0.93), there were significant differences by year (p < 0.01), school level (p < 0.001), and residential area at the time of the accident (p < 0.001). CONCLUSIONS: This study demonstrates that the children and adolescents examined had a sufficient amount of iodine during the period 1.5-4.5 years after the nuclear accident. In addition to the differences in the scale and the countermeasures undertaken between the Fukushima and Chernobyl accidents, differences in dietary iodine intake might have played an additional role in resulting in the reportedly different radiation doses to the thyroid between the two nuclear accidents.

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Factors affecting dilation force in balloon dilation of severe esophageal strictures: an experiment using an artificial stricture model.

Yoshitaka Nishikawa, Hirokazu Higuchi, Osamu Kikuchi, Yasumasa Ezoe, Ikuo Aoyama, Atsushi Yamada, Masataka Kanki, Shuhei Nomura, Motoo Nomura, Takahiro Horimatsu, Manabu Muto

Surgical endoscopy 30 （ 10 ） 4315 - 20 2016年10月

査読有り,  ISSN  0930-2794

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BACKGROUND: The multidiameter balloon catheter is used widely for severe esophageal stricture dilation. However, the relationships between inflation pressure, balloon size, and radial dilation force at the stricture site have not been examined fully. METHODS: We performed an experiment using phantom models to investigate the relationships between inflation pressure, balloon size, and radial dilation force. The balloon dilation procedure was performed for each stricture model using three sizes of balloon: 10-11-12, 12-13.5-15, and 15-16.5-18 mm. RESULTS: A positive association between inflation pressure and dilation force was observed for each balloon size. In balloons inflated by targeting the same diameter, the dilation force was higher for smaller balloons than for larger balloons. An inverse association between stricture size and dilation force was observed in the 12-13.5-15 mm balloon (3 vs 5 mm, P = .002; 5 vs 7 mm, P < .001). CONCLUSIONS: We found relationships between inflation pressure, balloon size, severity of strictures, and dilation force. To perform safe and effective esophageal balloon dilation, the inflation pressure and balloon size should be selected after considering the stricture size and target diameter.

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Impacts of the 2011 Fukushima nuclear accident on emergency medical service times in Soma District, Japan: a retrospective observational study.

Tomohiro Morita, Masaharu Tsubokura, Tomoyuki Furutani, Shuhei Nomura, Sae Ochi, Claire Leppold, Kazuhiro Takahara, Yuki Shimada, Sho Fujioka, Masahiro Kami, Shigeaki Kato, Tomoyoshi Oikawa

BMJ open 6 （ 9 ） e013205 2016年09月

査読有り,  ISSN  2044-6055

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OBJECTIVE: To assess the influence of the 3.11 triple disaster (earthquake, tsunami and nuclear accident) on the emergency medical service (EMS) system in Fukushima. METHODS: Total EMS time (from EMS call to arrival at a hospital) was assessed in the EMS system of Soma district, located 10-40 km north of the nuclear plant, from 11 March to 31 December 2011. We defined the affected period as when total EMS time was significantly extended after the disasters compared with the historical control data from 1 January 2009 to 10 March 2011. To identify risk factors associated with the extension of total EMS time after the disasters, we investigated trends in 3 time segments of total EMS time; response time, defined as time from an EMS call to arrival at the location, on-scene time, defined as time from arrival at the location to departure, and transport time, defined as time from departure from the location to arrival at a hospital. RESULTS: For the affected period from week 0 to week 11, the median total EMS time was 36 (IQR 27-52) minutes, while that in the predisaster control period was 31 (IQR 24-40) min. The percentage of transports exceeding 60 min in total EMS time increased from 8.2% (584/7087) in the control period to 22.2% (151/679) in the affected period. Among the 3 time segments, there was the most change in transport time (standardised mean difference: 0.41 vs 0.13-0.17). CONCLUSIONS: EMS transport was significantly delayed for ∼3 months, from week 1 to 11 after the 3.11 triple disaster. This delay may be attributed to malfunctioning emergency hospitals after the triple disaster.

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School restrictions on outdoor activities and weight status in adolescent children after Japan's 2011 Fukushima Nuclear Power Plant disaster: a mid-term to long-term retrospective analysis.

Shuhei Nomura, Marta Blangiardo, Masaharu Tsubokura, Sae Ochi, Susan Hodgson

BMJ open 6 （ 9 ） e013145 2016年09月

査読有り,  ISSN  2044-6055

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OBJECTIVE: Radiation fears following Japan's 2011 Fukushima nuclear disaster affected levels of physical activity in local children. We assessed the postdisaster versus predisaster weight status in school children and evaluated to what extent school restrictions on outdoor activities that were intended to reduce radiation exposure risk affected child weight. PARTICIPANTS: We considered children aged 13-15 years from 4 of the 5 secondary schools in Soma City (n=1030, 99.1% of all children in the city), located in 35-50 km from the Fukushima nuclear plant, postdisaster (2012 and 2015) and predisaster (2010). METHODS: Weight status, in terms of body mass index (BMI), percentage of overweight (POW) and incidence of obesity and underweight (defined as a POW ≥20% and ≤-20%, respectively) were examined and compared predisaster and postdisaster using regression models. We also constructed models to assess the impact of school restrictions on outdoor activity on weight status. RESULTS: After adjustment for covariates, a slight decrease in mean BMI and POW was detected in females in 2012 (-0.37, 95% CI -0.68 to -0.06; and -1.97, 95% CI -3.57 to -0.36, respectively). For male children, obesity incidence increased in 2012 (OR for obesity: 1.45, 95% CI 1.02 to 2.08). Compared with predisaster weight status, no significant weight change was identified in 2015 in either males or females. School restrictions on outdoor activities were not significantly associated with weight status. CONCLUSIONS: 4 years following the disaster, weight status has recovered to the predisaster levels for males and females; however, a slight decrease in weight in females and a slight increase in risk of obesity were observed in males 1 year following the disaster. Our findings could be used to guide actions taken during the early phase of a radiological disaster to manage the postdisaster health risks in adolescent children.

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Sociodemographic patterning of long-term diabetes mellitus control following Japan's 3.11 triple disaster: a retrospective cohort study.

Claire Leppold, Masaharu Tsubokura, Akihiko Ozaki, Shuhei Nomura, Yuki Shimada, Tomohiro Morita, Sae Ochi, Tetsuya Tanimoto, Masahiro Kami, Yukio Kanazawa, Tomoyoshi Oikawa, Sarah Hill

BMJ open 6 （ 7 ） e011455 2016年07月

査読有り,  ISSN  2044-6055

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OBJECTIVE: To assess the sociodemographic patterning of changes in glycaemic control of patients with diabetes affected by the 2011 triple disaster in Japan (earthquake, tsunami and nuclear accident). METHODS: A retrospective cohort study was undertaken with 404 patients with diabetes at a public hospital in Minamisoma City, Fukushima Prefecture. Glycated haemoglobin (HbA1c) levels were measured in 2010, 2011 and 2012 to capture changes in glycaemic control postdisaster. Age, sex, urban/rural residency, evacuation status and medication use were also assessed. RESULTS: There was an overall deterioration in glycaemic control after the disaster, with the mean HbA1c rising from 6.77% in 2010 to 6.90% in 2012 (National Glycohemoglobin Standardization Program, NGSP). Rural residency was associated with a lower likelihood of deteriorating control (OR 0.34, 95% CI 0.13 to 0.84), compared with urban residency. Older age (OR 0.95, 95% CI 0.91 to 0.98) was also slightly protective against increased HbA1c. Evacuation and sex were not significant predictors. CONCLUSIONS: Patients with diabetes who were affected by Japan's triple disaster experienced a deterioration in their glycaemic control following the disasters. The extent of this deterioration was mediated by sociodemographic factors, with rural residence and older age protective against the effects of the disaster on glycaemic control. These results may be indicative of underlying social determinants of health in rural Japan.

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Estimated association between dwelling soil contamination and internal radiation contamination levels after the 2011 Fukushima Daiichi nuclear accident in Japan.

Masaharu Tsubokura, Shuhei Nomura, Kikugoro Sakaihara, Shigeaki Kato, Claire Leppold, Tomoyuki Furutani, Tomohiro Morita, Tomoyoshi Oikawa, Yukio Kanazawa

BMJ open 6 （ 6 ） e010970 2016年06月

査読有り,  ISSN  2044-6055

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OBJECTIVES: Measurement of soil contamination levels has been considered a feasible method for dose estimation of internal radiation exposure following the Chernobyl disaster by means of aggregate transfer factors; however, it is still unclear whether the estimation of internal contamination based on soil contamination levels is universally valid or incident specific. METHODS: To address this issue, we evaluated relationships between in vivo and soil cesium-137 (Cs-137) contamination using data on internal contamination levels among Minamisoma (10-40 km north from the Fukushima Daiichi nuclear power plant), Fukushima residents 2-3 years following the disaster, and constructed three models for statistical analysis based on continuous and categorical (equal intervals and quantiles) soil contamination levels. RESULTS: A total of 7987 people with a mean age of 55.4 years underwent screening of in vivo Cs-137 whole-body counting. A statistically significant association was noted between internal and continuous Cs-137 soil contamination levels (model 1, p value <0.001), although the association was slight (relative risk (RR): 1.03 per 10 kBq/m(2) increase in soil contamination). Analysis of categorical soil contamination levels showed statistical (but not clinical) significance only in relatively higher soil contamination levels (model 2: Cs-137 levels above 100 kBq/m(2) compared to those <25 kBq/m(2), RR=1.75, p value <0.01; model 3: levels above 63 kBq/m(2) compared to those <11 kBq/m(2), RR=1.45, p value <0.05). CONCLUSIONS: Low levels of internal and soil contamination were not associated, and only loose/small associations were observed in areas with slightly higher levels of soil contamination in Fukushima, representing a clear difference from the strong associations found in post-disaster Chernobyl. These results indicate that soil contamination levels generally do not contribute to the internal contamination of residents in Fukushima; thus, individual measurements are essential for the precise evaluation of chronic internal radiation contamination.

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Social determinants of mid- to long-term disaster impacts on health: A systematic review

Shuhei Nomura, Alexander J. Q. Parsons, Mayo Hirabayashi, Ryo Kinoshita, Yi Liao, Susan Hodgson

INTERNATIONAL JOURNAL OF DISASTER RISK REDUCTION （ELSEVIER SCIENCE BV）  16   53 - 67 2016年06月

査読有り,  ISSN  2212-4209

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Disasters cause a wide range of health impacts. Although there remains a need to understand and improve acute disaster management, a stronger understanding of how health is affected in the medium and longer term is also required to inform the design and delivery of measures to manage post-disaster health risks, and to guide actions taken before and during events which will also lead to reduction in health impact. Social determinants exert a powerful influence on different elements of risk, principally vulnerability, exposure and capacity, and thus, on people's health. As disaster health data and research has tended to focus on the short-term health impacts, no systematic assessment of the social determinants of the mid- to long-term health impacts of disasters has been identified. We assessed the chronic health impacts of disasters and explored the potential socioeconomic determinants of health impact through a systematic review. Our findings, based on 28 studies, highlighted that regardless of health outcomes and event types, the influence of disasters on chronic heath persists beyond the initial disaster period, affecting people's health for months to years. Using the World Health Organization's conceptual framework for the social determinants of health, we identified a total of 35 themes across the three conceptual domains (determinants related to the socioeconomic and political context, structural determinants, and intermediate determinants) as potentially influencing disaster impact. Investment to tackle modifiable underlying determinants could aid disaster risk management, improve medium and long-term health outcomes from disasters, and build community resilience. (C) 2016 Elsevier Ltd. All rights reserved.

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An evaluation of early countermeasures to reduce the risk of internal radiation exposure after the Fukushima nuclear incident in Japan.

Shuhei Nomura, Masaharu Tsubokura, Stuart Gilmour, Ryugo S Hayano, Yuni N Watanabe, Masahiro Kami, Yukio Kanazawa, Tomoyoshi Oikawa

Health policy and planning 31 （ 4 ） 425 - 33 2016年05月

査読有り,  ISSN  0268-1080

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After a radiation-release incident, intake of radionuclides in the initial stage immediately following the incident may be the major contributor to total internal radiation exposure for individuals in affected areas. However, evaluation of early internal contamination risk is greatly lacking. This study assessed the relationship between initial stage evacuation/indoor sheltering and internal radiation contamination levels 4 months after the 2011 Fukushima nuclear incident in Japan and estimated potential pathways of the contamination. The study population comprised 525 participants in the internal radiation screening program at Minamisoma Municipal General Hospital, 23 km north of the Fukushima nuclear plant. The analysed dataset included the results of a screening performed in July 2011, 4 months after the incident, and of a questionnaire on early-incident response behaviours, such as sheltering indoors and evacuations, completed by participants. Association between such early countermeasures and internal contamination levels of cesium-134 were assessed using Tobit multiple regression analyses. Our study shows that individuals who evacuated to areas outside Fukushima Prefecture had similar contamination levels of cesium-134 to individuals who stayed in Fukushima (relative risk: 0.86; 95% confidence interval: 0.74-0.99). Time spent outdoors had no significant relationship with contamination levels. The effects of inhalation from radiological plumes released from the nuclear plant on total internal radiation contamination might be so low as to be undetectable by the whole-body counting unit used to examine participants. Given the apparent limited effectiveness of evacuation and indoor sheltering on internal contamination, the decision to implement such early responses to a radiation-release incident should be made by carefully balancing their potential benefits and health risks.

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Protecting human security: proposals for the G7 Ise-Shima Summit in Japan

Kenji Shibuya, Shuhei Nomura, Hiromasa Okayasu, Satoshi Ezoe, Seigo Hara, Yuriko Hara, Takashi Izutsu, Takuma Kato, Shunsuke Mabuchi, Yujiro Maeda, Yuki Murakami, Hiroko Nishimoto, Tomoko Ono, Kayoko Shioda, Atsushi Sorita, Amina Sugimoto, Kazuo Tase, Akihito Watabe, Anne Smith, Sarah K. Abe, Stuart Gilmour, Lawrence O. Gostin, Gavin Yamey, Marco Schaeferhoff, Elina M. Suzuki, Jessica Kraus, Takashi Oshio, Reiko Hayashi, Naoki Kondo, Koichiro Shiba, Hideo Yasunaga, Yusuke Sasabuchi, Yohsuke Takasaki, Naoki Akahane, Shingo Kasahara, Munehito Machida, Satoshi Maruyama, Shuushou Okada, Tadayuki Tanimura, Tomohiko Sugishita, Ikuo Takizawa, Maki Ozawa, Yoshiharu Yoneyama, Hidechika Akashi, Chiaki Miyoshi, Hitoshi Murakami, Toshiro Kumakawa, Satoko Horii, Kenichiro Taneda, Hideaki Shiroyama, Yasushi Katsuma, Makiko Matsuo, Sayako Kanamori, Chiaki Sato, Kayo Yasuda, Jonas Kemp, B. T. Slingsby, Kei Katsuno, Bumpei Tamamura, Keizo Takemi, Hideki Hashimoto, Michael R. Reich

LANCET （ELSEVIER SCIENCE INC）  387 （ 10033 ） 2155 - 2162 2016年05月

査読有り,  ISSN  0140-6736

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In today's highly globalised world, protecting human security is a core challenge for political leaders who are simultaneously dealing with terrorism, refugee and migration crises, disease epidemics, and climate change. Promoting universal health coverage (UHC) will help prevent another disease outbreak similar to the recent Ebola outbreak in west Africa, and create robust health systems, capable of withstanding future shocks. Robust health systems, in turn, are the prerequisites for achieving UHC. We propose three areas for global health action by the G7 countries at their meeting in Japan in May, 2016, to protect human security around the world: restructuring of the global health architecture so that it enables preparedness and responses to health emergencies; development of platforms to share best practices and harness shared learning about the resilience and sustainability of health systems; and strengthening of coordination and financing for research and development and system innovations for global health security. Rather than creating new funding or organisations, global leaders should reorganise current financing structures and institutions so that they work more effectively and efficiently. By making smart investments, countries will improve their capacity to monitor, track, review, and assess health system performance and accountability, and thereby be better prepared for future global health shocks.

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Postnuclear disaster evacuation and chronic health in adults in Fukushima, Japan: a long-term retrospective analysis.

Shuhei Nomura, Marta Blangiardo, Masaharu Tsubokura, Akihiko Ozaki, Tomohiro Morita, Susan Hodgson

BMJ open 6 （ 2 ） e010080 2016年02月

査読有り,  ISSN  2044-6055

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OBJECTIVE: Japan's 2011 Fukushima Daiichi Nuclear Power Plant incident required the evacuation of over a million people, creating a large displaced population with potentially increased vulnerability in terms of chronic health conditions. We assessed the long-term impact of evacuation on diabetes, hyperlipidaemia and hypertension. PARTICIPANTS: We considered participants in annual public health check-ups from 2008 to 2014, administrated by Minamisoma City and Soma City, located about 10-50 km from the Fukushima nuclear plant. METHODS: Disease risks, measured in terms of pre-incident and post-incident relative risks, were examined and compared between evacuees and non-evacuees/temporary-evacuees. We also constructed logistic regression models to assess the impact of evacuation on the disease risks adjusted for covariates. RESULTS: Data from a total of 6406 individuals aged 40-74 years who participated in the check-ups both at baseline (2008-2010) and in one or more post-incident years were analysed. Regardless of evacuation, significant post-incident increases in risk were observed for diabetes and hyperlipidaemia (relative risk: 1.27-1.60 and 1.12-1.30, respectively, depending on evacuation status and post-incident year). After adjustment for covariates, the increase in hyperlipidaemia was significantly greater among evacuees than among non-evacuees/temporary-evacuees (OR 1.18, 95% CI 1.06 to 1.32, p<0.01). CONCLUSIONS: The singularity of this study is that evacuation following the Fukushima disaster was found to be associated with a small increase in long-term hyperlipidaemia risk in adults. Our findings help identify discussion points on disaster planning, including preparedness, response and recovery measures, applicable to future disasters requiring mass evacuation.

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

Takeaki Ishii, Masaharu Tsubokura, Sae Ochi, Shigeaki Kato, Amina Sugimoto, Shuhei Nomura, Yoshitaka Nishikawa, Masahiro Kami, Kenji Shibuya, Yasutoshi Saito, Yukihide Iwamoto, Hidekiyo Tachiya

Disaster medicine and public health preparedness 10 （ 1 ） 34 - 7 2016年02月

査読有り,  ISSN  1935-7893

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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.

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Dependence of radiation dose on the behavioral patterns among school children: a retrospective analysis 18 to 20 months following the 2011 Fukushima nuclear incident in Japan.

Shuhei Nomura, Masaharu Tsubokura, Tomoyuki Furutani, Ryugo S Hayano, Masahiro Kami, Yukio Kanazawa, Tomoyoshi Oikawa

Journal of radiation research 57 （ 1 ） 1 - 8 2016年01月

査読有り,  ISSN  0449-3060

　概要を見る

After radioactive incidents, the exposure risk in daily activities among children is a major public concern. However, there are limited methods available for evaluation of this risk, which is essential to future health risk management. To this end, this study assessed the relationship between behavioral patterns of school children and radiation exposure for a period of 18-20 months following the 2011 Fukushima nuclear incident. The assessed population comprised 520 school children from Minamisoma city, located 20 km north of the nuclear plant. Data for the doses were obtained using individual dosimeters and from results of a behavior survey administered by the City Office. The mean value of the doses in the study period was 0.34 mSv, with a standard deviation of 0.14 mSv, indicating an annual dose of ∼1.36 mSv, which includes doses from natural sources. Our results showed that behavior with respect to outdoor activities had no statistically significant relationship to the dose. A 0.1 μSv/h increase in the air dose rate at home was associated with a 10% increase in the dose; however, a 0.01 μSv/h increase in the air dose rate on the school grounds was associated with a 2% increase in the dose. This study indicates that the air contamination levels at the places where children spend most of their day are the significant predictors of the dose, as opposed to the levels at those outdoor locations in which short periods of time spent.

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