RESUMO
Radiation disasters pose distinctive medical challenges, requiring diverse care approaches. Beyond radiation exposure assessment, addressing health impacts due to lifestyle changes, especially among vulnerable populations, is vital. Evacuation orders issued in radiation-affected areas introduce unique healthcare dynamics, with their duration significantly influencing the recovery process. Understanding evolving patient demographics and medical needs after lifting evacuation orders is crucial for post-disaster care planning. Minamisoma Municipal Odaka Hospital, located 13 to 20 km from Fukushima Daiichi Nuclear power plant in a post-evacuation zone, was greatly affected by the Great East Japan Earthquake and subsequent radiation disaster. Data were retrospectively collected from patient records, including age, gender, visit date, diagnoses, and addresses. Patient records from April 2014 to March 2020 were analyzed, comparing data before and after the July 2016 evacuation order lift. Data was categorized into pre and post-evacuation order lifting periods, using International Classification of Diseases, Tenth Edition codes, to identify the top diseases. Statistical analyses, including χ-square tests, assessed changes in disease distributions. Population data for Odaka Ward and Minamisoma City fluctuated after lifting evacuation orders. As of March 11, 2011, Odaka Ward had 12,842 residents (27.8% aged 65+ years), dropping to 8406 registered residents and 2732 actual residents by April 30, 2018 (49.7%). Minamisoma City also saw declines, with registered residents decreasing from 71,561 (25.9%) to 61,049 (34.1%). The study analyzed 11,100 patients, mostly older patients (75.1%), between 2014 and 2020. Post-lifting, monthly patient numbers surged from an average of 55.2 to 213.5, with female patients increasing from 33.8% to 51.7%. Disease patterns shifted, with musculoskeletal cases declining from 23.8% to 13.0%, psychiatric disorders increasing from 9.3% to 15.4%, and trauma-related cases decreasing from 14.3% to 3.9%. Hypertension (57.1%) and dyslipidemia (29.2%) prevailed post-lifting. Urgent cases decreased from 1.3% to 0.1%. This study emphasizes the importance of primary care in post-evacuation zones, addressing diverse medical needs, including trauma, noncommunicable diseases, and psychiatric disorders. Changing patient demographics require adaptable healthcare strategies and resource allocation to meet growing demands. Establishing a comprehensive health maintenance system tailored to these areas' unique challenges is crucial for future disaster recovery efforts.
Assuntos
Terremotos , Acidente Nuclear de Fukushima , Atenção Primária à Saúde , Humanos , Estudos Retrospectivos , Japão , Feminino , Masculino , Idoso , Pessoa de Meia-Idade , Adulto , Atenção Primária à Saúde/estatística & dados numéricos , Adolescente , Adulto Jovem , Criança , Planejamento em Desastres , Idoso de 80 Anos ou mais , Pré-Escolar , Lactente , Instituições de Assistência Ambulatorial/estatística & dados numéricosRESUMO
The medical situation during disasters often differs from that at usual times. Disasters can lead to significant mortality that can be difficult to monitor. The types of disaster-related deaths are largely unknown. In this study, we conducted a survey to categorize the disaster-related deaths caused by a radiation disaster. A total of 520 people living in Minamisoma City, Fukushima Prefecture, at the time of the Fukushima Daiichi Nuclear Power Plant accident, who were certified to have died due to disaster-related causes were surveyed. We divided the participants into those who were at home at the time of the earthquake and those who were in hospitals or facilities when the disaster struck and conducted a hierarchical cluster analysis of the two groups. Disaster-related deaths could be divided into seven groups for those who were at home at the time of the disaster and five groups for those who were in hospitals or facilities at the time of the disaster. Each group showed different characteristics, such as "the group with disabilities," "the group receiving care," and "the group with depression," and it became evident that not only uniform post-disaster support, but support tailored to the characteristics of each group is necessary.
Assuntos
Desastres , Terremotos , Acidente Nuclear de Fukushima , Humanos , Hospitais , Análise por Conglomerados , Japão/epidemiologia , Centrais NuclearesRESUMO
OBJECTIVES: This study aimed to identify factors that delayed emergency medical services (EMS) in evacuation order zones after the 2011 Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Plant accident and to investigate how the lifting of the evacuation affected these factors over time. DESIGN: This research was a retrospective observational study. The primary outcome measure was onsite EMS time. A gradient boosting model and a decision tree were used to find the boundary values for factors that reduce EMS. SETTING: The target area was Minamisoma City, Fukushima, Japan that was partly designated as an evacuation order zone after the 2011 Fukushima disaster, which was lifted due to decreased radiation. PARTICIPANTS: This study included patients transferred by EMS from 1 January 2013 through 31 October 2018. Patients who were not transported and those transported for community events, interhospital patient transfer and natural disasters were excluded. OUTCOME MEASURES: This study evaluated the total EMS time using on-site time which is the time from arrival at the scene to departure to the destination, and other independent factors. RESULTS: The total number of transports was 12 043. The decision tree revealed that the major factors that prolonged onsite time were time of day and latitude, except for differences by year. While latitude was a major factor in extending on-site time until 2016, the effect of latitude decreased and that of time of day became more significant since 2017. The boundary was located at N37.695° latitude. CONCLUSIONS: The onsite time delay in EMS in evacuation order zones is largely due to regional factors from north to south and the time of day. However, the north-south regional factor decreased with the lifting of evacuation orders.
Assuntos
Desastres , Terremotos , Acidente Nuclear de Fukushima , Humanos , Centrais Nucleares , Estudos Retrospectivos , JapãoRESUMO
Introduction: The health of patients with mental disorders, such as alcohol-related diseases, often deteriorates after disasters. However, the causes of death among those with alcohol-related diseases during and after radiation disasters remain unclear. Methods: To minimize and prevent alcohol-related deaths in future radiation disasters, we analyzed and summarized six cases of alcohol-related deaths in Minamisoma City, a municipality near the Fukushima Daiichi nuclear power plant. Results: Patients were generally treated for alcohol-related diseases. In one case, the patient was forced to evacuate because of hospital closure, and his condition worsened as he was repeatedly admitted and discharged from the hospital. In another case, the patient's depression worsened after he returned home because of increased medication and drinking for insomnia and loss of appetite. Discussion: The overall findings revealed that, in many cases, evacuation caused diseases to deteriorate in the chronic phase, which eventually resulted in death sometime after the disaster. To mitigate loss of life, alcohol-related diseases must be addressed during the chronic phases of future large-scale disasters, including nuclear disasters.
Assuntos
Desastres , Acidente Nuclear de Fukushima , Transtornos Mentais , Masculino , Humanos , Centrais Nucleares , EtanolRESUMO
To reveal waning humoral immunity after second dose BNT162b2 vaccinations in a rural Japanese community and determine factors affecting antibody titers. We aimed to report Immunoglobulin G (IgG) antibody against the SARS-CoV-2 spike (S1) protein levels and neutralizing activity in a large scale community based cohort. METHODS: Participants in the observational cross-sectional study received a second dose of vaccination with BNT162b2 (Pfizer/BioNTech) and were not previously infected with COVID-19. Questionnaire-collected data on sex, age, adverse vaccine reactions, and medical history was obtained. RESULTS: Data from 2496 participants revealed that older age groups reached a low antibody titer 90-120 days after the second vaccination. Neutralizing activity decreased with age; 35 (13.3%) of those aged ≥ 80 years had neutralizing activity under the cut-off value. Neutralizing activity > 179 days from the second vaccination was 11.6% compared to that at < 60 days from the second vaccination. Significantly lower IgG antibody titers and neutralizing activity were associated with age, male sex, increased time from second vaccination, smoking, steroids, immunosuppression, and comorbidities. CONCLUSIONS: Antibody titer decreased substantially over time. Susceptible populations, older people, men, smokers, steroid users, immunosuppression users, and people with three or more comorbidities may require a special protection strategy.
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COVID-19 , Vacinas , Masculino , Humanos , Idoso , Imunidade Humoral , Estudos Transversais , Vacina BNT162 , Anticorpos Antivirais , Japão , SARS-CoV-2 , COVID-19/prevenção & controle , Vacinação , Inquéritos e Questionários , Anticorpos NeutralizantesRESUMO
BACKGROUND: Disaster relief operations involve a variety of components of healthcare efforts. The post-disaster recovery is a key component of hospital preparedness. This study aimed to investigate the role of hospital nurses in the disaster area and their challenges during the relief efforts after the Great East Japan Earthquake in 2011. METHODS: Semi-structured interviews were conducted with ten nurses who worked in a general public hospital before the Great East Japan Earthquake and were dispatched to the evacuation centers after the disaster. A qualitative approach with the thematic analysis method was employed. Three research queries (RQs) were prepared before the interview. RESULTS: The study participants played administrative roles as city employees in addition to performing nursing services as healthcare providers in evacuation centers. The first RQ on their challenges in evacuation centers gave us four themes: criticism by the evacuees, conflicts between multiple roles, difficulties in performing the first experience, and anxiety in working. The second RQ asking about motivation to accomplish disaster relief efforts raised three themes of carrying out the nursing role, acceptance by evacuees, and strengths of human connections. Two themes of awareness of disaster medicine and professional growth were raised from the third RQ of gains from the experiences in the evacuation centers. CONCLUSIONS: The hospital nurses in the disaster area performed multiple roles in the relief efforts in the evacuation centers, which developed a psychological burden on them. A sense of competence supported the motivation to accomplish the disaster relief activities and professional growth as a specialist in disaster medicine. A study limitation is missing hospital nurses who resigned during the relief efforts. Further study is warranted to refine the disaster preparedness of hospital operations.
Assuntos
Planejamento em Desastres , Desastres , Terremotos , Hospitais , Humanos , JapãoRESUMO
Emergency evacuation during disasters may have significant health impacts on vulnerable populations. The Japanese Government issued evacuation orders for surrounding residents of the Fukushima Daiichi nuclear power plant (FDNPP) immediately after the March 11, 2011, nuclear accident. Little is known of difficulties associated with the disaster-specific evacuation from health care facilities located in this area. Among the 338 patients hospitalized at Futaba Hospital, located 4.6 km west of FDNPP, at the time of the accident, 39 patients (11.5%), predominantly critically ill patients who were bedridden or disabled, died before the evacuation was completed. The shortage of hospital staff and disruption of infrastructure resulted in a lack of adequate care provision, such as infusion therapy or sputum suctioning, leading to premature death of some hospitalized patients during the emergency hospital evacuation. As hospital evacuation is sometimes unavoidable during disasters, potential health impacts of hospital evacuation should be recognized and reflected in disaster preparedness plans.
Assuntos
Desastres , Acidente Nuclear de Fukushima , Humanos , Centrais Nucleares , Estudos Retrospectivos , Rádio (Anatomia) , Hospitais , JapãoRESUMO
OBJECTIVES: A previous report indicated that evacuation owing to the government order after the Fukushima disaster impacted the health status of older people; however, the association between living in evacuation areas and independence in their daily lives was unclear. This study examined the hypothesis that people who were forced to evacuate their homes were more likely to need long-term care (LTC). DESIGN: Historical cohort study. SETTING AND PARTICIPANTS: Older individuals (n = 13,934) in Minamisoma, Fukushima Prefecture, Japan, part of which was designated as an evacuation area. METHODS: Background and certification data from April 2012 to December 2016 were extracted. Logistic regression analysis with sex stratification was performed to examine the association between certification of care levels 1-5 and living in evacuation areas. RESULTS: In total, 18,178 Minamisoma residents aged ≥65 years who had not received LTC certification as of March 11, 2011, were eligible for follow-up. Of these, 4244 residents without a certificate of residence by June 1, 2016, were excluded. Of 13,934 residents followed up, 1553 (11.1%) were newly certified as care levels 1-5. Certification of care levels 1-5 was associated with living in evacuation areas [odds ratio (OR) 1.61, 95% confidence interval (CI) 1.20-2.18] and living alone at the time of the disaster (OR 2.58, 95% CI 1.92-3.47) in men and living alone at the time of the disaster (OR 1.35, 95% CI 1.15-1.59) in women. CONCLUSIONS AND IMPLICATIONS: Living in evacuation areas and living alone were associated with LTC certification. In evacuation areas, individuals with family members were more likely to be certified compared with those in nonevacuation areas. Among residents in evacuation areas, several individuals with family members experiencing family structure changes might need LTC. Preventive measures (including group relocation) may be beneficial for those being evacuated following a disaster.
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Desastres , Acidente Nuclear de Fukushima , Idoso , Estudos de Coortes , Feminino , Ambiente Domiciliar , Humanos , Japão , Assistência de Longa Duração , MasculinoRESUMO
Colorectal cancer (CRC) screening is a well-established cancer screening method, and its effectiveness depends on maintaining a high participation rate in the target population. In this study, we analyzed the trends in CRC screening participation rates over 10 years in Minamisoma City, where residents were forced to evacuate after the 2011 triple disaster in Fukushima, Japan. The immunochemical fecal occult blood test is provided as municipal CRC screening. We calculated the annual CRC screening participation rate and analyzed the factors associated with participation in screening. Overall, 4069 (12.3%) and 3839 (11.7%) persons participated in CRC screening in 2009 and 2010, respectively; however, the number decreased significantly to 1090 (3.4%) in 2011 when the earthquake occurred. Over the following 3 years, the rate gradually recovered. Multivariable logistic analysis showed that age < 65 years, living alone, and evacuation were significant associated factors for non-participation after 2011 (p < 0.05). In conclusion, the CRC screening participation rate decreased significantly during the Great East Japan Earthquake but recovered over the next 3 years. Further analysis of factors preventing CRC screening participation and research on the long-term effects of its post-disaster decline are important to consider in assessing the need for intervention in post-disaster cancer screening.
Assuntos
Neoplasias Colorretais/epidemiologia , Detecção Precoce de Câncer/tendências , Acidente Nuclear de Fukushima , Participação do Paciente/tendências , Adulto , Idoso , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Sangue Oculto , Sobreviventes/estatística & dados numéricosRESUMO
The health status of healthy decontamination workers employed after the Fukushima nuclear disaster remains unclear. This study aimed to evaluate the prevalence of non-communicable diseases among such workers. In this observational study, questionnaires on lifestyle and social factors were administered as part of a health promotion program for decontamination workers in 2016 in Minamisoma City, Fukushima. The questionnaires and health check-up results were compared with those of the 2016 National Health and Nutrition Examination Survey (NHANES) in Japan. Overall, 123 male decontamination workers were enrolled; 93 (75.6%) were drinkers, and 84 (68.3%) were current smokers. The age-adjusted prevalence (95% confidence interval) of hypertension, dyslipidemia, diabetes mellitus, and obesity were 27.2% (20.1-34.4%), 30.4% (22.6-38.2%), 11.3% (5.5-17.1%), and 49.0% (39.0-58.9%), respectively. The age-adjusted prevalence in the NHANES were 32.8% (31.1-34.5%), 16.1% (14.5-17.6%), 7.0% (6.2-7.7%), and 31.2% (29.9-32.5%), respectively. The prevalence of obesity, dyslipidemia, binge drinking, and smoking were higher in healthy male decontamination workers than in the general population. Decontamination workers in disaster-struck areas may have higher risks of developing non-communicable diseases, possibly due to their original health status. Continuous monitoring of their health status and proper interventions are warranted.
Assuntos
Descontaminação/métodos , Acidente Nuclear de Fukushima , Doenças não Transmissíveis/epidemiologia , Exposição Ocupacional , Exposição à Radiação , Adulto , Humanos , Incidência , Japão/epidemiologia , Masculino , Pessoa de Meia-IdadeRESUMO
Background: As a result of the Fukushima Daiichi nuclear power plant accident, many residents evacuated and were exposed to changes in their living environment and socioeconomic status, and to persistent stressors. Past studies have suggested the potential for these circumstances to contribute to long-term changes to population health.Objective: The objective of this study was to gain a better understanding of long-term health effects of evacuation, by evaluating the risk of non-communicable diseases among evacuees from Minamisoma City (one of the closest municipalities to the power plant) until 2017.Methods: The study evaluated data from annual health check-ups for residents aged 40-74 years covered by National Health Insurance (who are largely self-employed) from 2010 to 2017 administered by Minamisoma City. Diabetes, hyperlipidemia, and hypertension were defined from the results of blood sampling. Annual changes in age-adjusted prevalence were estimated by evacuation scenario. We also performed an inverse-probability weighting (IPW) analysis to adjust for baseline covariates in 2010 and estimated the differences in the risk of diabetes, hyperlipidemia, and hypertension by evacuation scenario as of the 2017 health check-up in reference to the no-evacuation group.Results: A total of 1,837 individuals were considered in this study. Regardless of evacuation scenario, there was statistical evidence suggesting an upward and a downward trend in diabetes and hypertension from 2010 to 2017, respectively, while hyperlipidemia showed no remarkable change. IPW analyses demonstrated that disease risks in 2017 did not differ significantly among people with different evacuation scenarios.Conclusions: Region-specific factors played an important role in the health effects of the evacuation. Our findings have important implications for the need of an assessment of the health effects of evacuations in more localized manner. Further research in this area will strengthen the communities' preparedness for future disasters that require mass evacuation.
Assuntos
Acidente Nuclear de Fukushima , Doenças não Transmissíveis , Humanos , Doenças não Transmissíveis/epidemiologia , Centrais Nucleares , Estudos Retrospectivos , Medição de RiscoRESUMO
ABSTRACT: Following the lifting of the evacuation order due to the Fukushima Daiichi Nuclear Power Plant accident, the medical demand and emergency medical system (EMS) in the area where the evacuation orders were lifted have not been well-investigated. This study aimed to evaluate the emergency transportation in such areas and compare the differences with areas that had minimal impact.Using the local EMS transport records, the characteristics of patients who were transferred by an EMS vehicle in Minamisoma City were collected between July 12, 2016 and July 31, 2018, and were compared between former evacuation zones and outside the evacuation zones in the city.The number of emergency transports in the study period in Minamisoma City were 325 cases in the area where the evacuation orders were lifted and 4307 cases in the other areas. The total EMS time was significantly longer in the area where the evacuation order was lifted (48â±â16âminutes) than in the other areas (40â±â15âminutes) (Pâ<â.001). In the analysis of each component of EMS times, the transport time, which is the time from departure from the patient's location to arrival at a hospital, was significantly longer in the former evacuation zone than in the other areas (16â±â9 vs 9â±â9âminutes, Pâ<â.001), suggesting that transport time contributed to the longer EMS response times.In areas where the evacuation orders were lifted, the EMS transport time was significantly longer than that in the area outside the former evacuation zone; correspondingly, the total EMS time significantly increased in the former evacuation zone. A plausible reason for this may be the closure of local medical facilities following the evacuation order after the nuclear accident.
Assuntos
Ambulâncias/estatística & dados numéricos , Emergências , Serviços Médicos de Emergência/estatística & dados numéricos , Acidente Nuclear de Fukushima , Adolescente , Adulto , Idoso , Ambulâncias/organização & administração , Criança , Pré-Escolar , Cidades , Estudos Transversais , Serviços Médicos de Emergência/organização & administração , Feminino , Humanos , Lactente , Recém-Nascido , Japão , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Adulto JovemRESUMO
Emergency evacuation during a disaster may have serious health implications in vulnerable populations. After the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011, the Japanese central government immediately issued an evacuation order for residents living near the plant. There is limited information on the process of evacuation from medical institutions within the evacuation zone and the challenges faced. This study collected and analyzed publicly available resources related to the Futaba Kosei Hospital, located 3.9 km northwest of the FDNPP, and reviewed the hospital's evacuation procedures. On the day of the accident at the FDNPP, 136 patients were admitted in the aforementioned hospital. The hospital's director received information about the situation at the FDNPP from the local disaster task force and requested the immediate evacuation of all patients. Consequently, four patients, including those with an end-stage condition, died during the evacuation. Early intervention by external organizations, such as the Japan Self-Defense Forces, helped the hospital to complete the evacuation without facing major issues. However, despite such an efficient evacuation, the death of four patients suggests that a significant burden is placed on vulnerable people during emergency hospital evacuations. Those with compromised health experience a heavy burden during a nuclear disaster. It is necessary for hospitals located close to a nuclear power plant to develop a more detailed evacuation plan by determining the methods of communication with external organizations that could provide support during evacuation to minimize the burden on vulnerable patients.
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Comportamento Cooperativo , Emergências , Acidente Nuclear de Fukushima , Hospitais , Tomada de Decisões , Geografia , Humanos , JapãoRESUMO
Responding to the radiation-related concerns of parents/guardians with infants/small children is an important public health issue for regional recovery after radioactive contamination. This study summarizes the results of a systematic internal contamination screening of infants/small children, aged 0-6 years, using BABYSCAN and individual counselling sessions with physicians about radiation concerns from 2014 to 2018 in Minamisoma City. Of 3,114 participants, no one was found to have internal contamination with radioactive caesium with a detection limit of 50 Bq/body. The questionnaire survey showed a decreasing trend of concerns about food contamination and playing outside as possible causes of internal contamination over time. Because people's concerns were diverse in counselling sessions, individual responses are required. This study showed that examinations using BABYSCAN provide an opportunity for direct dialogue between the parents/guardians of infants/small children and experts. This can be considered a model case for risk communication conducted by the local government after a radioactive contamination incident.
Assuntos
Radioisótopos de Césio/análise , Contagem Corporal Total/estatística & dados numéricos , Criança , Pré-Escolar , Exposição Ambiental/estatística & dados numéricos , Feminino , Contaminação Radioativa de Alimentos/estatística & dados numéricos , Acidente Nuclear de Fukushima , Humanos , Lactente , Recém-Nascido , Japão , Masculino , Centrais Nucleares , Monitoramento de Radiação/estatística & dados numéricos , Liberação Nociva de Radioativos/estatística & dados numéricos , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
After the Fukushima accident, airborne monitoring was implemented to measure airborne radiation. We examined the relationships between airborne and individual radiation monitoring and clarified the use of airborne monitoring to evaluate the effects of decontamination on residents' received doses. We used the air dose rate data from four airborne monitors conducted between 2013 and 2016, and the dose data from four individual monitors (in which a total of 18 392 adults and 3650 children participated), conducted in Minamisoma City during the same period. We examined the Pearson correlation coefficients between the airborne and individual monitoring data and estimated exposure ratios (ERs; ratios of individual dose to air dose rates) among adults and children. We also estimated the effects of decontamination on residents' doses based on airborne monitoring data, adjusting this for timing and dosing through propensity score matching, which were then compared to individual monitoring data. There were significant correlations between airborne and individual monitoring doses among adults and children, and more than 80% of residents showed a good estimation-observation agreement within a factor of two. The median of ERs was 0.304 and 0.250 among adults and children, respectively. There was a significant difference between the two. Effects of decontamination on residents' doses estimated from airborne monitoring were significantly lower than those estimated from individual monitoring. These findings suggest that airborne monitoring can be used to estimate representative radiation doses within residential areas. It may be a useful tool for enhancing communication among stakeholders and supporting individual and policy decisions; however, it is less sensitive for evaluating individual effects of decontamination than individual monitoring. Combined use of airborne and individual monitoring also showed a lower median of ERs in children than in adults and in a Japanese government's model, possibly due to prioritised decontamination for children and differences between their behavioral patterns.
RESUMO
Following the Fukushima incident, radiation doses from external exposure accounted for the majority of the total doses. Although countermeasures are being implemented, with the aim of reducing radiation exposure, little information is available on the effects of decontamination on individual doses among the residents of radioactively contaminated areas. To evaluate the effectiveness of the decontamination measures in reducing individual doses, and to examine the influence of the timing of decontamination and the district, data were analysed for 18 392 adults and 3 650 children in Minamisoma City, Fukushima, who participated in a voluntary screening programme using individual radiation dosimeters (Glass Badge) between June 2013 and September 2016. The dose reduction rates (DRR) were calculated for one year by comparing the first and last three-month measurement results between areas with and without decontamination. Using a regression approach and Monte Carlo simulation, the dose reduction rate by decontamination eliminating the effect of physical decay (DRRd') was also estimated as a function of the timing of the decontamination and the dose at the time of starting the decontamination. The annual DRR in areas with decontamination for both adults and children were significantly higher than those in areas without decontamination, depending on the timing of decontamination: 31%-36% for 2013-14 for adults in decontamination areas and 33%-35% for children in decontamination areas, compared to 12%-23% and 13%-23% for adults and children in areas without decontamination, respectively. There was a positive correlation between DRRd' and individual doses, and DRRd' was estimated at 30%-40% for adults and children with doses of 3 mSv y-1 in 2013 and 2014. This study demonstrated that decontamination does lower individual doses from external exposure. The higher the dose at the time of starting the decontamination, the greater the dose reduction rate by decontamination, regardless of the timing of the decontamination. Our study confirms that decontamination was useful for high-dose areas in the later phases of the incident.
Assuntos
Descontaminação/métodos , Exposição Ambiental/análise , Acidente Nuclear de Fukushima , Doses de Radiação , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Cidades , Feminino , Humanos , Lactente , Recém-Nascido , Japão , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Método de Monte Carlo , Dosímetros de Radiação , Monitoramento de Radiação/métodos , Estudos RetrospectivosRESUMO
After the 2011 Fukushima Daiichi nuclear power plant accident, evidence on the real-life conditions of returnees to areas once designated as legal no-go zones, including their radiation dose levels, is scarce. In the present study, using a radiation dosimeter and lifestyle survey, we evaluated the lifestyle characteristics and dose levels in 2017 from external exposure among those who returned to the no-go zones after the evacuation orders were lifted. A total of 112 returnees to Odaka district, Minamisoma City, Fukushima Prefecture, were considered and compared to 266 non-returnees. The proportion of participants with annual additional doses from external exposure above 1 mSv was 7.0% for returnees, and 7.3% and 4.2% for non-returnees living in other districts or outside of the city, respectively. Although caution is required given the very small sample sizes, this implies that as of 2017 doses from external exposure among returnees in Odaka were very low and by scientific consensus would be associated with a very low likelihood of physical effects. We also found that while returnees were older on average than non-returnees, they had similar life conditions (i.e. occupation and time spent outdoors). It should be particularly emphasised that the expected lifetime doses from the incident in addition to the natural background dose are a very small among returnees. This study contributes to enhancing societal debates and risk communication regarding how government can provide returnees with the support they need, improve their outlook for radiation doses, and continue to improve crucial infrastructure in former no-go zones so that communities can be rebuilt.