Besides the first 4 mo external radiation exposure dose estimation in Fukushima, the data obtained from individual dose measurement using glass dosimeters and by whole-body counter have been accumulated (Nagataki 2012), indicating no alarming evidence of radiation-induced health consequences.
FOUR DETAILED SURVEYS
The four detailed surveys being conducted are: (1) thyroid ultrasound examination, (2) comprehensive medical checkup, (3) mental health and lifestyle surveys, and (4) survey of pregnant women and nursing mothers (FMU 2013).
Thyroid ultrasound examination
Although health effects due directly to radiation exposure are highly unlikely under the current circumstances and radiation levels in Fukushima, an increase in childhood thyroid cancer was seen in Chernobyl from internal exposure to radioactive iodine. Because of the strict requirement by people in Fukushima as well as the central and local governments, we started the most sophisticated thyroid ultrasound examinations in October 2011, targeting the children who were <18 y old at the time of the accident (around 360,000 for every 2 y as long as the children are <20 y old and then every 5 y when their age is >20 y old). These examinations will be repeated for a long time and will follow a standardized protocol developed by the FMU in cooperation with related hospitals and organizations. The protocol of thyroid ultrasound examination is well established so that a highly sophisticated diagnostic approach is implemented with standardized data collection (Fig. 10).
As of March 2012, within 1 y after the accident, ∼38,000 people from the evacuation zones (80% population) have received examinations, and the data were analyzed. Results showed that the majority did not have issues, although some did exhibit slight lumps (nodular lesions) or cysts. Approximately 0.5% of these individuals required detailed follow-up examinations (precision ultrasound, blood tests, urine analysis, and biopsies where appropriate). Among them, three cases of childhood thyroid cancer were diagnosed and successfully operated on, and seven more cases have been suspected as malignant following fine needle aspiration biopsy examination. It needs to be noted that the sophisticated screening activities for thyroid disease that are underway in the Fukushima region will also lead to an increase in the incidence of thyroid cancer due to earlier detection of non-symptomatic cases. It will therefore not be possible to compare the future observed thyroid cancer incidence with the figures of any previous report, due to the baseline changes due to the screening activities. In this respect, it is necessary to establish a system for a long-term follow-up for all the children in Fukushima in careful comparison with the control areas. The overall results on 133,089 children have been reported (Table 1), and the examinations that will be carried out in the next several years are extremely vital for laying the foundation for long-term health management. After completion of these preliminary (first round) examinations for clarification of basal prevalence of thyroid diseases within 3 y, the full-scale thyroid examinations (second round) will start in April 2014, hopefully targeting an established cohort population of 360,000 children from the entire Fukushima Prefecture at the time of the accident.
Detailed health examinations are being performed on the residents of evacuation zones and also on those deemed to be in need of healthcare based on their responses to the basic survey. The target population is around 210,000, including children who resided in the evacuated zones at the time of accident. The main objectives are to assess the examinees’ health conditions and achieve early diagnoses and treatment of lifestyle issues and/or illnesses. The content of the examinations differs depending on the examinee’s age, although all tests included in “Specified Medical Checkups” are typically conducted. For persons aged 16 y or older, the Special Health Checkup, as a part of the Municipal National Health Insurance system, has been performed with additional items for comprehensive health check among adults aged 40 y or older in Hirono-machi, Naraha-machi, Tomioka-machi, Kawauchi-mura, Okuma-machi, Futaba-machi, Namie-machi, Kazurao-mura, and Iitate-mura (Fig. 11). Also, mass health check visits have been held for a total of 104 times at 29 locations since January 2012 for people aged 16 y or older who do not participate in the Special Health Checkup. For children aged 15 y or younger, health checks have been held since January 2012 at 102 pediatric medical institutions in the Prefecture. Comprehensive health checks have been performed outside the Prefecture with the cooperation of the Japan Anti-Tuberculosis Association.
In summary, the 2011 Comprehensive Health Check from around 70,000 examinations clarified the general health conditions of evacuees from the government-designated evacuation zone after the Great East Japan Disaster. Obesity and hyperlipidemia exist even at young ages and increase in comparison with the previous years’ data obtained from Fukushima Prefecture for both male and female adults. Liver dysfunction and hyperuricemia increase at relatively young ages in males. Furthermore, hypertension, glucose dysmetabolism, and renal dysfunction increase in adulthood and are most common at older ages. We compared the comprehensive health check results after the disaster with the results of health examinations performed before the disaster in children and adults. The results suggested that the rates of obesity, glucose metabolic dysfunction, hyperlipidemia, and liver dysfunction after the disaster were high compared with those before the disaster. Regarding the factors that contributed to these results, changes of lifestyle, diet, exercise, and other personal habits caused by forced evacuation are suggested, although there were interfering factors such as the difference in health check period, age distribution, region distribution, and participation rate. Based on the results of the health check carried out in 2011, we are continuing the comprehensive health check for the long-term and maintaining the system to prevent various diseases, including lifestyle related, of participants.
Mental health and lifestyle surveys
Changes in mental and physical health were indicated as the long-term effects of the Chernobyl nuclear reactor accident. Since psychological stress is conceivable in residents coping with life in evacuee shelters and anxiety toward radiation, surveys are being administered to enable the provision of appropriate care. Residents in evacuation zones and individuals (∼210,000 people) deemed in need of health care based on basic survey results are asked to respond to questions about their current physical and mental condition, lifestyle (diet, sleeping habits, tobacco use, alcohol use, and exercise), how they have spent the past half year, and their experience of the Great East Japan Earthquake. Among them, around 92,000 people responded to the specific questionnaire that included the Strengths and Difficulties Questionnaire, Kessler’s 6, and Post-Traumatic Stress Disorder Check List scoring issues. Individuals who need counseling and support are provided with telephone consultations by a clinical psychologist or other members of the Mental Health Support Team. If the support team member decides that specialized treatment is required, a physician from the FMU Radiation Health Counseling Team responds and conducts examinations as necessary. Although detailed analysis will be separately reported, there are two important findings. For children, the most remarkable issues are physical symptoms, influences on school performance, irritation, anxiety and depression, and sensitivity to earthquakes and radiation taken from the category of “Reactions Amongst Children Due to 3.11 Disaster.” For adults, the most remarkable issues are sleep issues, physical problems, depression, fear of the future, agitation, and discounting of evacuation life, taken from the category of “Reaction to Self from the 3.11 Disaster.” All these data are still acute phase reactions, so we need to follow them up for a long time to compare the difference between acute and chronic reactions and also to clarify the quality of psychosocial and mental changes in order to support the recovery of physical and mental health conditions. Indeed, there are 3,351 individuals among the 73,569 population analyzed so far who need a care or support for their lifestyle related issues, such as sleep disturbance, chronic alcoholism, and smoking.
Although studies of populations exposed to low doses are limited in their ability to account for important lifestyle factors, such as cigarette smoking and medical x-ray exposures, our investigations should be and are being considered for reassurance and health care reasons. Therefore, mental health care in Fukushima will be essential for a long time as recommended by several experts; this is similar to expert recommendations following the Chernobyl accident (Bromet et al. 2011; Boice 2012).
Survey of expectant and nursing mothers
A survey was administered to women who received their Maternal and Child Health Handbooks within and outside the Prefecture and to those who underwent pregnancy checkups or gave birth after 11 March 2011. They were asked to respond to questions including the health and pregnancy checkups they received since the earthquake, their physical condition during their pregnancy, the birth of their child, and their mental well being. A total of 15,954 questionnaires were distributed in January 2011, and 9,266 responses were returned by 31 August 2012 (response rate 58.1%). Telephone counseling was provided by midwives and public health nurses for 1,393 of 9,228 respondents (counseling rate 15.1%) who had been identified as requiring support on the basis of the survey response (1,213 indicated signs of depression and 180 requested support on their own). Along with protecting the long-term health of expectant and nursing mothers, these efforts are intended to provide peace of mind to those planning childbirth in Fukushima Prefecture and help improve perinatal care in the Prefecture.
At the FMU Radiation Medical Science Center, maternity and public health nurses are always on duty, handling calls and e-mails related to childcare and child rearing. For consultees who require further support, FMU maternity and hospital nurses are available by telephone. In certain cases, the patient’s existing obstetrician or an FMU professor may offer support. According to the local reports, there was no increase in miscarriage nor artificial abortion thanks to the extensive efforts of the Japanese Medical Association, especially obstetricians and gynecologists. Furthermore the Japan Association of Obstetricians and Gynecologists (JAOG) evaluated congenital malformations in babies delivered in Fukushima Prefecture. There is no obvious increased prevalence of congenital malformations at the present time compared with the rate of birth defects monitoring by JAOG. However, it is necessary to gather more cases to draw a conclusion.
REGULAR HEALTH CHECKUPS TO SUPPORT RECOVERY EFFORTS
The surveys are intended as a specific response to initial radiation exposure and to mental traumas caused by the accident and evacuation. The standardization and close monitoring of diagnostic examinations outside of these surveys remain pending issues in the context of long-term health management efforts. In particular, it is important not only for patients but for the public to understand that due to the latent period for cancer induction, if an ultrasound thyroid examination shows signs of cancer in <4 y after the accident, there is no tenable argument that could link that cancer to radiation exposure from the accident. Going forward, we need to address the issue of latency periods regarding examination results and the development of cancer from the standpoint of cancer biology. Also, we need to devise a regional cancer registry for patients. Birth, illness, old age, and death are inevitable, and a risk-free society is not completely achievable. Although much has been lost, some things have been gained as a result of this recent tragedy. Fortunately, there have been no deaths from radiation exposure due to the nuclear accident. It seems that being grateful for having life (being allowed to live) and facing difficulties alongside our companions contribute to further hope and courage.
RESPONSIBILITY OF MEDICAL AND HEALTH PROFESSIONALS
In view of the severity of the accident, even though it was rare, Japan, which previously aimed to become a nuclear power-based nation, still aims to be a science and technology-oriented nation and to be familiar with the medical knowledge about and techniques for handling nuclear and radiological accidents. Now we are facing more difficult aspects of a recovery and reconstruction with existing radiation exposure conditions not only in Fukushima but surrounding prefectures, which may now have radiation levels similar to natural high background areas in the world.
First, there needs to be a common understanding about the role and responsibility of health care workers in any emergency and reconstruction process using similar considerations as those used for disaster prevention. As we know, what is done cannot be undone; it is necessary for officials and others to understand the difference between the concept of radiation protection in ordinary time and radiation protection during emergencies as well as the importance of involving the stakeholders in each community.
The world has been enlightened not only by the information of the nuclear accident itself but also by efforts to reduce and mitigate medical exposure. In the case of routine medical exposure, there is no recommended dose limit set, but justification includes the judgment of the physician; the diagnosis and radiological treatment for the patient is based on the conceptual agreement that the benefits are much greater than the radiation risk. Of course, the effort to reduce and avoid exposure in any circumstance is required, but a concept of justification is the most important key word in medical exposure for any facilitator, including physicians and radiologists. On the other hand, use of artificial radioactive material is done using principles and measures to prevent exposure in other areas, such as the prevention of the spread of contamination and protection of workers.
The large amount of radioactive material that was released from the Fukushima NPP accident into the environment has raised new issues regarding exposure of the general population. The residents in Fukushima were exposed to unnecessary and useless environmental radioactive contamination, especially by radioactive 134Cs and 137Cs. It is important for medical professionals to provide an appropriate response for the residents with the aim of recovery and reconstruction after the accident. Lessons of the Chernobyl nuclear reactor accident need to be used in this instance, not only with regard to the health aspect but also the risk-and-benefit side and the concept of dose limit and reference level. Furthermore, evaluation from various perspectives, including the psychosocial aspects, is necessary to understand the concept of optimization of exposure reduction measures. Since there are many complexities in the aftermath of the Fukushima NPP accident, we, the Japanese, need to be more aware of ICRP activities, such as the need to consider the justification and optimization of protection strategies and the introduction and application of a reference level to drive the optimization process (ICRP 2009). The ICRP emphasizes strongly the effectiveness of involving stakeholders directly in the management of difficult conditions.
The above countermeasures should be learned by medical professionals themselves in order to communicate with the public. Moreover, medical staff members are expected to perform beyond their normal duties during and after nuclear and radiological accidents, especially to support the return of workers to the contaminated areas, which should have an annual dose less than several millisievert after any official restricting regulations have been withdrawn (Fig. 12). Support activities for ensuring security and safety are then needed for those who will decide to return back to their home place in the future.
The risk of radiation-associated physical health consequences for residents in Fukushima is quite different from that of Chernobyl and considerably low or undetectable based on the estimated radiation doses individuals received during the accident. However, there are similarities in the social, psychological, and economic impacts between two serious NPP accidents. Therefore, the current ongoing program of the Fukushima Health Management Survey is essential to support long-term comprehensive health management and mental care for the residents and evacuees from Fukushima.
As we support residents in their recovery and return to their homes, understanding each individual’s state with respect to radiation and regularly monitoring their health conditions contribute to the region’s rebirth and restoration (Taira et al. 2012). To that end, we plan to build and maintain a framework for residents to self-access information about their radiation dose rates and for the medical infrastructure to offer readily accessible health consultations and examinations. The challenges associated with the health care management of Fukushima Prefecture’s residents are numerous, and it is only with the support of everyone that we will be able to move forward with these projects. We humbly request the kind consideration and cooperation of the prefecture’s and country’s healthcare professionals and also of the international societies.
The slogan of FMU is “Let’s Change Our Tragedy to Miracle—Start Together from Fukushima with Health and Medical Science Research.” Our goals include overcoming the complications of this nuclear disaster, changing and reforming our difficult and disordered psychosocial situation, and leading Fukushima in transforming in the future into the “Number One Prefecture of Longevity in Japan.”
This special honorable occasion of the Tenth Annual Warren K. Sinclair Keynote Address is devoted to all the victims in sorrow by the Great East Japan Earthquake. I really appreciate the Fukushima Health Management Survey Group at FMU and also Nagasaki University, especially Shigenobu Nagataki and Vladimir Saenko. Preparation of this paper was supported in part by the grant 25257508 from the Japan Society for the Promotion of Science.
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dose reconstruction; exposure, radiation; health effects; National Council on Radiation Protection and Measurements; Chernobyl; Fukushima
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