Masaharu Tsubokura

Dr. Masaharu Tsubokura

Fukushima Medical University, Fukushima, Japan
orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
15 August 2012 in JAMA
Verified
Journal Article
Open access
PDF file
MTMasaharu Tsubokura
Masaharu Tsubokura
SGStuart Gilmour
Stuart Gilmour
KTKyohei Takahashi
Kyohei Takahashi
TOTomoyoshi Oikawa
Tomoyoshi Oikawa
YKYukio Kanazawa
Yukio Kanazawa
To the Editor: On March 11, 2011, an earthquake and tsunami struck Japan and led to a meltdown of the reactors at the Fukushima Daiichi nuclear power plant. Release of radioactive material into the air, water, and soil raised concern about internal radiation exposure and the long-term risk of cancer in nearby residents.1 However, radiation exposure has not been measured.

26 March 2013 in PLOS ONE
Verified
Journal Article
Open access
PDF file
SNShuhei Nomura
Shuhei Nomura
SGStuart Gilmour
Stuart Gilmour
MTMasaharu Tsubokura
Masaharu Tsubokura
Daisuke YoneokaDaisuke Yoneoka
Daisuke Yoneoka
ASAmina Sugimoto
Amina Sugimoto
KSKenji Shibuya
Kenji Shibuya
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. 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. 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). 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.

1 January 2013 in Proceedings of the Japan Academy, Series B
Verified
Journal Article
Open access
RHRyugo S. Hayano
Ryugo S. Hayano
MTMasaharu Tsubokura
Masaharu Tsubokura
MMMakoto Miyazaki
Makoto Miyazaki
HSHideo Satou
Hideo Satou
KSKatsumi Sato
Katsumi Sato
YSYu Sakuma
Yu Sakuma
The Fukushima Dai-ichi NPP accident contaminated the soil of densely-populated regions in Fukushima Prefecture with radioactive cesium, which poses significant risks of internal and external exposure to the residents. If we apply the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv/y would be expected to be frequent in Fukushima.

1 August 2014 in Disaster Medicine and Public Health Preparedness
Verified
Journal Article
Closed access
PDF file
YKYuko Kodama
Yuko Kodama
TOTomoyoshi Oikawa
Tomoyoshi Oikawa
KHKaoru Hayashi
Kaoru Hayashi
MTMichiko Takano
Michiko Takano
MNMayumi Nagano
Mayumi Nagano
YKYukio Kanazawa
Yukio Kanazawa
Objective: To elucidate the impacts of nuclear plant accidents on neighboring medical centers, we investigated the operations of our hospital within the first 10 days of the Great East Japan Earthquake followed by the Fukushima Daiichi nuclear power plant accident.Methods: Data were extracted from medical records and hospital administrative records covering 11 to 20 March 2011. Factual information on the disaster was obtained from public access media.Results: A total of 622 outpatients and 241 inpatients were treated. Outpatients included 43 injured, 6 with cardiopulmonary arrest, and 573 with chronic diseases. Among the 241 inpatients, 5 died, 137 were discharged, and the other 99 were transferred to other hospitals. No communication methods or medical or food supplies were available for 4 days after the earthquake. Hospital directors allowed employees to leave the hospital on day 4. All 39 temporary workers were evacuated immediately, and 71 of 239 full-time employees remained. These employees handled extra tasks besides patient care and patient transfer to other hospitals. Committed effective doses indicating the magnitude of health risks due to an intake of radioactive cesium into the human body were found to be minimal according to internal radiation exposure screening carried out from July to August 2011.Conclusions: After the disaster, hospitals located within the evacuation zone of a 30-km radius of the nuclear power plant were isolated. Maintenance of the health care system in such an event becomes difficult. (Disaster Med Public Health Preparedness. 2014;8:471-476)

22 March 2017 in Asia Pacific Journal of Public Health
Verified
Journal Article
Closed access
MMMichio Murakami
Michio Murakami
ASAkiko Sato
Akiko Sato
SMShiro Matsui
Shiro Matsui
AGAya Goto
Aya Goto
AKAtsushi Kumagai
Atsushi Kumagai
Sae OchiSae Ochi
Sae Ochi
The Fukushima nuclear accident in March 2011 posed major threats to public health. In response, medical professionals have tried to communicate the risks to residents. To investigate forms of risk communication and to share lessons learned, we reviewed medical professionals’ activities in Fukushima Prefecture from the prefectural level to the individual level: public communication through Fukushima Health Management Surveys, a Yorozu (“general”) health consultation project, communications of radiological conditions and health promotion in Iitate and Kawauchi villages, dialogues based on whole-body counter, and science communications through online media. The activities generally started with radiation risks, mainly through group-based discussions, but gradually shifted to face-to-face communications to address comprehensive health risks to individuals and well-being. The activities were intended to support residents’ decisions and to promote public health in a participatory manner. This article highlights the need for a systematic evaluation of ongoing risk communication practices, and a wider application of successful approaches for Fukushima recovery and for better preparedness for future disasters.

4 February 2016 in BMJ Open
Verified
Journal Article
Open access
PDF file
SNShuhei Nomura
Shuhei Nomura
MBMarta Blangiardo
Marta Blangiardo
MTMasaharu Tsubokura
Masaharu Tsubokura
AOAkihiko Ozaki
Akihiko Ozaki
TMTomohiro Morita
Tomohiro Morita
SHSusan Hodgson
Susan Hodgson
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.