著者

Mai Takiguchi Tetsuya Ohira Hironori Nakano Yui Yumiya Takayoshi Yamaki Akiomi Yoshihisa Kazuhiko Nakazato Hitoshi Suzuki Tetsuo Ishikawa Seiji Yasumura Kenji Kamiya Yasuchika Takeishi

出版者

International Heart Journal Association

雑誌

International Heart Journal (ISSN:13492365)

巻号頁・発行日

pp.19-110, (Released:2019-10-31)

参考文献数

24

被引用文献数

5

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On March 11, 2011, a great earthquake, known as the Great East Japan Earthquake, hit northeastern Japan, resulting in a tsunami that caused a nuclear disaster, the Fukushima Daiichi Nuclear Power Plant accident, forcing about 160,000 people to evacuate. We, therefore, sought to examine the effects of this evacuation on the onset of cardiovascular diseases and sudden death (SD) in Fukushima Prefecture, three years after the earthquake. We divided the evacuation zone into two areas, whole evacuation zone (Area 1) and partial evacuation zone (Area 2), and we defined the north district of the prefecture as the control area (Area 3). We cross-referenced the death certificate data with data from the Fukushima Prefecture acute myocardial infarction registration survey. For each area, we tallied the number of people who fell into the SD, myocardial infarction (MI), and MI suspected groups. We calculated the age-adjusted incidence rates and analyzed the differences in the adjusted incidence rates across three years using a Poisson regression model. The age-adjusted death rate of the SD group was significantly higher in 2011 in all areas than in 2012 or 2013 (P < 0.05). The total death rate was higher in Area 1 in March 2011, just after the disaster, than in the other two areas. The rate of SD was also higher in Area 1 than in the other areas in March 2011. The incidence of sudden cardiac death might have increased just after the Great East Japan Earthquake in the evacuation area, but not in other areas in Fukushima Prefecture.

著者

MAKOTO MIYAZAKI AKIRA OHTSURU TETSUO ISHIKAWA

出版者

福島医学会

雑誌

FUKUSHIMA JOURNAL OF MEDICAL SCIENCE (ISSN:00162590)

巻号頁・発行日

pp.2014-10, (Released:2014-07-15)

参考文献数

15

被引用文献数

3 16

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A large amount of radioactive cesium was released by the Fukushima Daiichi Nuclear Power Plant accident following the Great East Japan Earthquake. Due to the increasing concerns about internal exposure, more than 50 whole-body counters (WBCs) have been installed at various locations in Fukushima Prefecture. A study on around 10,000 subjects in the early stage after the accident revealed that very few received a committed effective dose of more than 0.3 mSv for subjects (age >13 years old). Another study on WBC results for one hospital showed that the ratio of cesium-positive was 1.0% among all the subjects. Assuming a constant daily intake, the detection limit of 300 Bq/body for a typical WBC corresponds to an effective dose of 21 μSv/y even for a subject of age up to 10. It was also seen out that the subjects with a significant amount of body cesium are likely to regularly eat wild products, which they harvested or caught themselves without testing for radioactive cesium. These study findings suggested that the internal exposure for most of the residents was controlled at a very low level. Future tasks regarding WBC measurements are how to personally explain the WBC results to each subject and how to disclose the statistically processed WBC data to the general public.

著者

Seiji Yasumura Tetsuya Ohira Tetsuo Ishikawa Hiroki Shimura Akira Sakai Masaharu Maeda Itaru Miura Keiya Fujimori Hitoshi Ohto Kenji Kamiya

出版者

Japan Epidemiological Association

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

vol.32, no.Supplement_XII, pp.S3-S10, 2022-12-05 (Released:2022-12-05)

参考文献数

46

被引用文献数

11 22

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The Fukushima Health Management Survey (FHMS) was established in response to the Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011. The primary objectives of the study are to monitor residents’ long-term health and promote their future well-being, and to determine the health effects of long-term low-dose radiation exposure. This special issue summarizes the results and current status of the FHMS and discusses the challenges and future directions of the FHMS. The FHMS, a cohort study of all people who were residents in Fukushima Prefecture at the time of the accident, consists of a Basic Survey, Thyroid Ultrasound Examination, Comprehensive Health Check, Mental Health and Lifestyle Survey, and Pregnancy and Birth Survey. The radiation exposure was estimated based on the behavioral records examined using the Basic Survey. Although the response rate was low in the Basic Survey, the representativeness of the radiation exposure data was confirmed using additional surveys. There appears to be no relationship between the radiation exposure and risk of thyroid cancer, although more thyroid cancer cases were detected than initially expected. The ongoing Comprehensive Health Check and Mental Health and Lifestyle Survey have provided evidence of worsening physical and mental health status. The Pregnancy and Birth Survey showed rates of preterm delivery, low birth weight, and congenital abnormalities similar to the national average. Considering the above evidence, the Fukushima Prefectural Government decided to end the Pregnancy and Birth Survey at the end of March 2021, as recommended by the Prefectural Oversight Committee. The framework of the FHMS has not changed, but the FHMS needs to adapt according to the survey results and the changing needs of the eligible residents and municipalities.

著者

Yasutaka Omori Hiroaki Wakamatsu Atsuyuki Sorimachi Tetsuo Ishikawa

出版者

福島医学会

雑誌

FUKUSHIMA JOURNAL OF MEDICAL SCIENCE (ISSN:00162590)

巻号頁・発行日

vol.62, no.1, pp.1-17, 2016 (Released:2016-06-08)

参考文献数

49

被引用文献数

1 14

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This study was conducted on the Fukushima Medical University (FMU) premises (in Fukushima City, Fukushima Prefecture) about four years after the Fukushima Daiichi Nuclear Power Plant accident. Its objectives were (1) to create a map of the ambient gamma dose rate (air-kerma rate) distribution, (2) to evaluate the air-kerma rate originating from natural radionuclides, and (3) to investigate the effects of snow cover on changes in the air-kerma rate. This man-borne survey revealed that the air-kerma rate varies widely, ranging from 0.038 μGy h-1 to 0.520 μGy h-1, and is higher on grass than on the other investigated surface types, such as soil, asphalt, and bricks. In this area, the mean air-kerma rate from natural radiation was evaluated to be 0.03 ± 0.01 μGy h-1, which is close to 0.04 μGy h-1, which was measured in central Fukushima City by a local authority.Furthermore, snowfall was found to reduce the air-kerma rate by 5%-30%. This reduction was attributed to attenuation of the primary radiation while passing through the snow cover, and the measured contribution of scattered radiation to the air-kerma rate reduction was small. The reduction rate was found to depend on the initial snow depth but to maintain a similar value for a couple of days, after the snow had partially melted and its depth had decreased. Finally, analysis of the daily dose due to external exposure received on the FMU premises revealed that no further health effects due to chronic radiation exposure at this site are to be expected.

著者

Itaru Miura Masanori Nagao Hironori Nakano Kanako Okazaki Fumikazu Hayashi Mayumi Harigane Shuntaro Itagaki Hirooki Yabe Masaharu Maeda Tetsuya Ohira Tetsuo Ishikawa Seiji Yasumura Kenji Kamiya

出版者

Japan Epidemiological Association

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

vol.32, no.Supplement_XII, pp.S95-S103, 2022-12-05 (Released:2022-12-05)

参考文献数

34

被引用文献数

4

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Background: The relationship between radiation levels and mental health status after a nuclear disaster is unknown. We examined the association between individual external radiation doses and psychological distress or post-traumatic stress after the Fukushima Daiichi nuclear power plant accident in March 2011 in Japan.Methods: The Mental Health and Lifestyle Survey was conducted from January 2012. Based on the estimated external radiation doses for the first 4 months, a total of 64,184 subjects were classified into <1 mSv, 1 to <2 mSv, and ≥2 mSv groups. Odds ratios (ORs) and 95% confidence intervals (CIs) of psychological distress and post-traumatic stress, with the <1 mSv group as the reference, were calculated using logistic regression analysis adjusted for age, sex, evacuation, perception of radiation risk, and subjective health status.Results: The prevalence of psychological distress/post-traumatic stress in the <1 mSv, 1 to <2 mSv, and ≥2 mSv groups was 15.1%/22.1%, 14.0%/20.1%, and 15.0%/21.7%, respectively. In women, although the ≥2 mSv group tended to have a higher risk of psychological distress with the age-adjusted OR of 1.13 (95% CI, 0.99–1.30), the adjusted OR decreased to 1.00 (95% CI, 0.86–1.16) after controlling for all variables. On the other hand, there were no dose-dependent associations between radiation dose and post-traumatic stress.Conclusion: Although external radiation doses were not associated with psychological distress, evacuation and perception of radiation risk may increase the risk of psychological distress in women in the higher dose group.

著者

Akira Sakai Masanori Nagao Hironori Nakano Tetsuya Ohira Tetsuo Ishikawa Mitsuaki Hosoya Michio Shimabukuro Atsushi Takahashi Junichiro J. Kazama Kanako Okazaki Fumikazu Hayashi Seiji Yasumura Hitoshi Ohto Kenji Kamiya

出版者

Japan Epidemiological Association

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

vol.32, no.Supplement_XII, pp.S84-S94, 2022-12-05 (Released:2022-12-05)

参考文献数

42

被引用文献数

6

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Background: Associations have been reported between lifestyle-related diseases and evacuation after the Great East Japan Earthquake (GEJE). However, the relationship between lifestyle-related diseases and the effective radiation dose due to external exposure (EDEE) after the GEJE remains unclear.Methods: From among 72,869 residents of Fukushima Prefecture (31,982 men; 40,887 women) who underwent a comprehensive health check in fiscal year (FY) 2011, the data of 54,087 residents (22,599 men; 31,488 women) aged 16 to 84 years were analyzed. The EDEE data of 25,685 residents with incomplete results from the basic survey, performed to estimate the external radiation exposure dose, were supplemented using multiple imputation. The data were classified into three groups based on EDEE (0 to <1, 1 to <2, and ≥2 mSv groups and associations between the incidence of diseases and EDEE from FY2011 to FY2017 were examined using a Cox proportional hazards model, with FY2011 as the baseline.Results: A higher EDEE was associated with a greater incidence of hypertension, diabetes mellitus, dyslipidemia, hyperuricemia, liver dysfunction, and polycythemia from FY2011 to FY2017 in the age- and sex-adjusted model. However, after further adjustment for evacuation status and lifestyle-related factors, the significant associations disappeared. No association was found between EDEE and other lifestyle-related diseases.Conclusion: EDEE was not directly associated with the incidence of lifestyle-related diseases after the GEJE. However, residents with higher external radiation doses in Fukushima Prefecture might suffer from lifestyle-related diseases related to evacuation and the resultant lifestyle changes.

著者

Tetsuo Ishikawa Seiji Yasumura Keiichi Akahane Shunsuke Yonai Akira Sakai Osamu Kurihara Mitsuaki Hosoya Ritsu Sakata Tetsuya Ohira Hitoshi Ohto Kenji Kamiya

出版者

Japan Epidemiological Association

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

vol.32, no.Supplement_XII, pp.S11-S22, 2022-12-05 (Released:2022-12-05)

参考文献数

35

被引用文献数

9

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Background: One of the components of the Fukushima Health Management Survey (FHMS) is the Basic Survey, which estimates individual external doses for the first 4 months after the 2011 nuclear power plant accident. However, external exposure continues long-term. According to estimations by international organizations, the external dose during the first year accounts for a significant part of the long-term dose. Thus, the present study was intended to estimate the first-year doses by extrapolating the Basic Survey results.Methods: For most municipalities of non-evacuated areas, ambient dose rate had been continuously measured for at least one designated point in each municipality after the accident. In the present study, a municipality-average dose received by residents for a period was assumed to be proportional to the ambient dose measured at the designated point of that municipality during the same period. Based on this assumption, 4-month municipality-average doses calculated from the Basic Survey results were extrapolated to obtain first-year doses.Results: The extrapolated first-year doses for 49 municipalities in the non-evacuated areas had a good correlation with those estimated by UNSCEAR, although the extrapolated doses were generally higher (slope of the regression line: 1.23). The extrapolated municipality-average doses were in reasonable agreement (within 30%) with personal dosimeter measurements, suggesting that the extrapolation was reasonable.Conclusion: The present paper reports the first 4-month average doses for all 59 municipalities of Fukushima Prefecture and the extrapolated first-year doses for 49 municipalities. The extrapolated doses will be the basis for future epidemiological studies related to the FHMS.

著者

Yoshiyuki Kojima Susumu Yokoya Noriaki Kurita Takayuki Idaka Tetsuo Ishikawa Hideaki Tanaka Yoshiko Ezawa Hitoshi Ohto

出版者

THE FUKUSHIMA SOCIETY OF MEDICAL SCIENCE

雑誌

FUKUSHIMA JOURNAL OF MEDICAL SCIENCE (ISSN:00162590)

巻号頁・発行日

vol.65, no.3, pp.76-98, 2019 (Released:2020-01-09)

参考文献数

116

被引用文献数

9

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Cryptorchidism (undescended testes) is among the most common congenital diseases in male children. Although many factors have been linked to the incidence of cryptorchidism, and testicular androgen plays a key role in its pathogenesis, the cause remains unknown in most cases. Recently, a Japanese group published a speculative paper entitled, “Nationwide increase in cryptorchidism after the Fukushima nuclear accident.” Although the authors implicated radionuclides emitted from the Fukushima accident as contributing to an increased incidence of cryptorchidism, they failed to establish biological plausibility for their hypothesis, and glossed over an abundance of evidence and expert opinion to the contrary. We assessed the adequacy of their study in terms of design setting, data analysis, and its conclusion from various perspectives. Numerous factors must be considered, including genetic, environmental, maternal/fetal, and social factors associated with the reporting of cryptorchidism. Other investigators have established that the doses of external and internal radiation exposure in both Fukushima prefecture and the whole of Japan after the accident are too low to affect testicular descent during fetal periods;thus, a putative association can be theoretically and empirically rejected. Alternative explanations exist for the reported estimates of increased cryptorchidism surgeries in the years following Japan’s 2011 earthquake, tsunami, and nuclear crisis. Data from independent sources cast doubt on the extent to which cryptorchidism increased, if at all. In any case, evidence that radionuclides from the Fukushima Daiichi Nuclear Power Plant could cause cryptorchidism is lacking.