The thyroid gland uses iodine to produce thyroid hormones and cannot distinguish between radioactive and stable (non-radioactive) iodine. If a large amount of radioactive iodine is absorbed by the thyroid gland, the probability of thyroid cancer increases due to radiation exposure from inside the gland.

After the Fukushima Daiichi Nuclear Power Plant accident, the amount of radioactive iodine released was only about one-fifteenth (1/15)* that of the Chornobyl accident. Also in contrast to Chornobyl, prompt evacuation, immediate management of the food supply distribution, consumption restrictions, and other countermeasures after the Fukushima accident minimized the amount of radioactivity to which people were exposed, thereby making radiation-related health effects unlikely.

* Calculated based on the data from UNSCEAR 2020/2021 Report

In the case-control study, people's ingested doses from tap water and inhaled doses from air were estimated for 14 days after the accident as the basis for their internal radiation exposure doses.

Analysis adjusting for factors such as gender, birth year, and number of examinations received did not reveal a statistically significant increasing trend in the relationship between "malignant or suspicious for malignancy" findings and radiation dose, expressed as an odds ratio.

The odds ratio appears to be increasing steadily, although not significantly, which may be due to factors arising from other examinations, such as the number of cases that proceed to confirmatory examinations or cytological diagnoses, but we treat these as factors that cannot be adjusted for.
We continue to collect and analyze relevant data.

Yes, in addition to cancers detected through the FHMS Thyroid Ultrasound Examination, some are diagnosed and treated for thyroid cancer through subsequent follow-up examinations or other pathways. We also consider data from the national Cancer Registry, in which people diagnosed with cancer at hospitals nationwide are registered, for cases in case-control studies.
We are evaluating as many thyroid cancer cases as possible at this time and are looking for possible cause-and-effect relationships.

Yes, this was discussed at the 20th Meeting of the Thyroid Examination Evaluation Subcommittee on March 20, 2023.
For more information, please refer to the Fukushima Prefectural Government website. For any inquiries about detailed information from any academic society, please contact them directly.

The male: female ratio for thyroid cancer is about 1:3, according to national data for all ages.
The male: female ratio in Fukushima is lower than the national data, suggesting relatively more males are being diagnosed. This may be related to the fact that our Thyroid Ultrasound Examination program focuses on children to young adults. As participants proceed to the Age 25 Survey, the male: female ratio moves in the direction of national data, suggesting that the gender ratio in Fukushima may be influenced by the younger average age of those who have been examined.

This may be related to newly diagnosed cases among those who had not participated in the preliminary baseline examination, along with the fact that examinees are getting older as they continue to have periodic examinations.

The FHMS Thyroid Ultrasound Examination covers children born to mothers who were pregnant around the time of the nuclear accident, specifically, those born through April 1, 2012.
The reason for this is that childhood thyroid cancer due to radiation exposure is thought to be caused mainly by internal exposure to radioactive iodine, and examinations are being conducted to acknowledge the possibility of internal exposure to radioactive iodine in utero, even if only a little.

On the other hand, radioactive iodine has a short physical half-life of 8 days, so most of it from the nuclear accident was gone by late April 2011. Moreover, doses from TEPCO's Fukushima Daiichi Nuclear Power Plant accident are known to be much lower than those from the Chornobyl nuclear accident.
Thus, for children born after April 1, 2012, internal exposure to radioactive iodine from the accident is unlikely, so there is no compelling ethical or scientific basis for including them in the Thyroid Ultrasound Examination program.

For the number of persons who have not undergone surgery after being diagnosed as malignant or suspected of malignancy, please refer to page 8 of the presentation slides for the number of malignant or suspected malignant patients and the number of persons who underwent surgery at the first- to fifth-round examinations and subsequent Age 25 and Age 30 examinations.
Please note that the number of cases in which surgery was performed at other medical institutions after being diagnosed or during follow-up is not known, so an actual ratio cannot be stated with certainty.

Effects of radiation exposure can have a latency period of several years or more. Moreover, compared to exposures of 100 mSv or less, the effects on health are greater from lifestyle habits such as smoking, drinking, poor dietary habits, stress, or lack of exercise. This is why we have chosen examination items for the early detection and prompt treatment of various diseases, including preventable lifestyle-related diseases, for all those who needed to evacuate due to the Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Plant Accident, whose lifestyles have changed drastically.

Although the incidence of certain diseases in a population can be affected by radiation exposure, individual cases cannot be attributed specifically to radiation. So, rather than trying to identify radiation effects, examination items are mainly intended for early detection and prompt treatment of various diseases, including lifestyle-related diseases.

The schedule depends on an individual's eligibility for the different kinds of methods, so please refer to the Fukushima Health Management Survey "MIMAMORI" website for details.

In addition to utilizing health check systems provided by municipalities, the Comprehensive Health Check has been conducted in several ways to allow residents in or from the covered area* to receive a Comprehensive Health Check in the context of their actual living circumstances, considering the situation of residents who have evacuated in and out of the prefecture.

* Municipalities designated as evacuation zones in 2011:
Hirono Town, Naraha Town, Tomioka Town, Kawauchi Village, Okuma Town, Futaba Town, Namie Town, Katsurao Village, Iitate Village, Minamisoma City, Tamura City, Kawamata Town, and a part of Date City (areas designated as Specific Spots Recommended for Evacuation)

The consent form for data use asks for your consent for Fukushima Prefecture and Fukushima Medical University to obtain data on the results of the Comprehensive Health Check and responses to questionnaires and to provide such data to the municipality where you resided at the time of the earthquake. Health data from consent participants are analyzed statistically in a way that does not identify individual participants. Statistical findings are intended to guide healthcare decision-making in ways that promote and maintain everyone’s health.
Please note that you can take the Comprehensive Health Check without submitting the consent form.

For those who receive specific and general health checks conducted by the municipalities (Hirono Town, Naraha Town, Tomioka Town, Kawauchi Village, Okuma Town, Futaba Town, Namie Town, Katsurao Village, Iitate Village, Minamisoma City, Tamura City, and Kawamata Town), additional items for the Fukushima Health Management Survey Comprehensive Health Check are included, so separate participation in our Comprehensive Health Check is not necessary. Others are recommended to participate in specific Comprehensive Health Check opportunities besides being organized at places of business or public venues, according to information sent to eligible participants.

Statistical analysis shows that lifestyle-related diseases (NCD) such as hypertension, diabetes, and dyslipidemia increased in people with estimated radiation exposures over 2 mSv/year, but this association disappears when evacuation and related lifestyle changes such as smoking and drinking habits are considered.

Even though no statistically significant association has emerged between low-level radiation exposure and lifestyle-related diseases, scientifically speaking, the possibility of such an association is not zero, so we need to collect and analyze longer-term data.

Concerning evacuation status or other "adjustment" factors, consider the example of comparing stroke incidence rates in Town A and Town B. Age has a significant impact on stroke incidence rates, so if the age distributions in Towns A and B were different, we must adjust for age-related effects when comparing stroke incidence rates.
Thus, the word "adjustment" applies to this process.

Although there is no specific research to show an association between increased atrial fibrillation and direct effects of radiation, some research has investigated risk factors of increased atrial fibrillation and white blood cell counts.

After the 3.11 disaster, the prevalence of atrial fibrillation increased among residents in the evacuation zone of Fukushima Prefecture. Significant risk factors for the development of atrial fibrillation were heavy alcohol consumption and obesity.
In addition, an evaluation of post-disaster atrial fibrillation and white blood cell counts showed that the prevalence of atrial fibrillation among residents of evacuated areas was associated with monocyte counts and neutrophil/lymphocyte ratios, suggesting the involvement of inflammation and psychological stress as possible factors in the development of post-disaster atrial fibrillation.

In general, it is well-known that diabetes increases after a major natural disaster or severe accident. Diabetes is indeed increasing among people with an estimated radiation exposure dose over 2 mSv/year, but we assume that the effect of evacuation is the most significant factor, since there is no significant difference after adjusting for the effects of evacuation.
Of course, we are not dismissing the possible effects of radiation; we need longer-term observations to make any valid conclusions.

After a follow-up survey of initially non-diabetic persons for 7 years, we found that diabetes increased due to the stress caused by evacuation, and further research revealed that it was more likely in men.

One possible reason for this is that women tend to express openly that they are stressed, while men do not and tend to be in a much more advanced state of stress by the time they respond to the survey.
We assume that the gender difference in the way men and women respond to the survey may also indicate that the relationship between diabetes onset and stress is more likely to emerge in men.

Although Comprehensive Health Check results have been available from FY2011, comparable data from immediately after the 3.11 disaster, including white blood cell counts, is not available because the Comprehensive Health Check did not start in the intended municipalities until July 2011.

We have compared it with the Aizu region in Fukushima Prefecture but not with other prefectures.

This survey is conducted to accurately assess the mental and physical health conditions and lifestyles of prefectural residents, in order to provide appropriate health, medical, and social welfare care for individuals who may be anxious or distressed from the Great East Japan Earthquake, Fukushima Daiichi Nuclear Power Plant accident, and/or life as an evacuee.

1. All persons who were registered residents of the respective municipalities* anytime from March 11, 2011, to April 1, 2012.
2. Residents who are registered in the respective municipalities* as of April 1 of the survey year.

Those who fall into category 1 will remain eligible even if they change their registered residence.

* Municipalities designated as evacuation zones in 2011:
Hirono Town, Naraha Town, Tomioka Town, Kawauchi Village, Okuma Town, Futaba Town, Namie Town, Katsurao Village, Iitate Village, Minamisoma City, Tamura City, Kawamata Town, and part of Date City (areas designated as Specific Spots Recommended for Evacuation)

A questionnaire by itself will not find all of the respondents' problems, but it can suggest the presence of depression or other mood disorders. Information to guide further support can be found in responses to the questionnaire.

For those who are in need of consultation and support in terms of mental health and lifestyle, the "KOKOKARA Health Support Team," consisting of certified psychologists, public health nurses, and other nurses provides telephone support. For those who are considered to be in need of continuous support, the team provides assistance in cooperation with registered doctors* and municipalities in which they are currently living.

* Doctors who have attended specialized training sessions on disaster mental health and radiation medicine (i.e., sessions organized or accredited by Fukushima Medical University).

Survey results are intended to help respondents understand mental health and lifestyle factors that can be addressed or managed for better health.

As the KOKOKARA survey was started after the disaster, there is no way to compare current findings with anything before the disaster. From long-term trends among people affected by the disaster, it is clear that many people are suffering from mental distress, but there is no data available to show how much this may have increased since before the disaster.
Therefore, we think it is important for each local municipal government to regularly monitor mental health and have a system in place that can utilize this data when responding to a future disaster.

To secure supporters, the collaboration of relevant organizations is essential. In addition, personal connections cultivated over time are invaluable for expanding circles of support.
Furthermore, in terms of supporting the supporters and disaster-affected people, it is crucial to acknowledge the possibility that exhaustion and anger of the victims may be directed toward their supporters in the immediate aftermath of a disaster. The supporters themselves are likely to be stressed in such situations.

The KOKOKARA survey asked about perceptions of acute, later-life, and next-generation radiation risks.
Questions on acute effects have been omitted since FY2013, and those on later effects have been omitted since FY2021, when a simplified survey questionnaire was introduced. Concerning later effects, questions will be reintroduced in the detailed survey scheduled for FY2025.

The Pregnancy and Birth Survey was conducted annually from FY2011 to FY2020 (Main Survey) to know the mental and physical health status, opinions, and requests of expectant and nursing mothers who intend to give birth and raise children in Fukushima Prefecture, to alleviate their anxiety and provide necessary care, and to improve obstetric and perinatal care in Fukushima Prefecture in the future.

Results of the Pregnant and Birth Survey's Main Survey showed a particularly high percentage of respondents with depressive tendencies after the 3.11 earthquake, tsunami, and Fukushima Daiichi Nuclear Power Plant accident. The first Follow-up Survey was conducted from FY2015 to FY2018 among those who responded the Main Survey from FY2011 to FY2014.

The first Follow-up Survey showed that respondents of the main survey in FY2011 and FY2012 had strong anxiety about the effects of radiation and a high percentage of depression; since there were still a certain number of respondents with poor subjective health, depression, and anxiety about the effects of radiation in the 2013 and 2014 surveys, a second Follow-up Survey was conducted from FY2019 to FY2022.

The Main Survey showed that rates of preterm birth, low birth weight, and congenital anomalies in Fukushima differed little from national data or commonly reported estimates for any year. Similarly, there were virtually no differences in the incidences of congenital anomalies among different regions within the prefecture.

Pertaining to maternal mental health, a tendency toward depression was elevated at the beginning of the survey but subsequently showed a decreasing trend.

Regarding maternal mental health, in particular the percentage of mothers with depressive tendencies, the percentage was higher in the second follow-up survey than in the first follow-up survey of FY2012 to FY2014. This may be due to the COVID-19 epidemic, since the second follow-up survey was conducted from FY2020 to FY2022.

The percentage of respondents who checked at least one item of concern about radiation effects showed a decreasing trend over time. The percentage of respondents who were concerned about "children's health" has also decreased over the years.

We will share results and findings of the survey in an easy-to-understand manner, posting them on our website and distributing flyers to those eligible for maternal and child health handbooks. Also, we will share survey results, and guidance on how to support municipalities, at workshops hosted by Fukushima Prefecture for maternal and child health leaders in municipalities.

When we began this Pregnancy and Birth Survey, our mission was not only to conduct the Survey but also to provide proper support to pregnant women.
In the case of surveys covering hospitals or other healthcare institutions, it is not possible to provide individualized care to pregnant and nursing mothers, so we distributed questionnaires to individuals, asked each person to respond, and then offered support. The response rate was around 50%, which is considered relatively high compared to the response rate for general surveys.

On the other hand, "congenital anomalies monitoring" has been conducted for about 50 years by the Japan Society of Obstetricians and Gynecologists and Yokohama City University. Currently, the program is being carried out with the support of over 300 childbirth facilities nationwide, with a focus on secondary and tertiary hospitals. However, in the aftermath of the 3.11 disaster, all childbirth facilities in Fukushima Prefecture were included through the cooperation of related institutions. So far, there has been no evidence of any increase in congenital anomalies specific to Fukushima Prefecture.

Furthermore, another survey of pregnancies, spontaneous miscarriages, and abortions, conducted by FMU's Obstetrics and Gynecology Department, with a 100% response rate from all obstetrics and gynecology providers in Fukushima Prefecture, showed no specific increases in spontaneous miscarriage or abortion rates after the disaster.

The survey confirmed that incidences of birth defects and congenital anomalies in Fukushima were consistent with national averages. Additionally, the tendency towards postpartum depression was found to be on par with the national average. These were the reasons why the survey was closed after 10 years.

In the years following the 3.11 disaster, we reported survey results to public health nurses in each municipality, as well as to midwives and nurses at obstetrics and gynecology clinics and hospitals in five different locations in Fukushima Prefecture. We have continued to report survey results to public health nurses and midwives at prefecture-sponsored training sessions for maternal and child health leaders once a year.
The national press has reported on several occasions that incidences of birth defects and congenital anomalies in Fukushima Prefecture are on par with national averages. Perhaps due to widespread acceptance of this equivalence and a corresponding loss of public interest, the press has ceased reporting on the matter.

However, the dissemination of scientific data is crucial. We remain committed to disseminating survey results and related information at every possible opportunity by participating in academic conferences, creating informative leaflets that summarize the findings, and making informative videos to be posted on our website.

The Pregnancy and Birth Survey is for those who were issued a maternal and child health handbook by a municipality in Fukushima Prefecture between August 1, 2012, and July 31, 2020, and those who were issued a maternal and child health handbook outside the prefecture during the aforementioned period, but who received prenatal checkups and gave birth in the prefecture.
The survey includes questions about pre-existing conditions but does not explicitly address thyroid cancer.

At the 2023 International Symposium, we shared the results of our research on the connection between a mother's "external radiation dose" and major results of pregnancy. Please refer to page 14 of the presentation slides for more information.

As stated in a 2014 research paper (*1), congenital anomalies are multifactorial, and the southern part of Fukushima prefecture did exhibit a significantly higher incidence. However, this cannot be attributed solely to external radiation exposure.
In fact, external exposure doses in the southern part of the prefecture were not higher than those in the northern and central parts of the prefecture. Subsequent research (*2), also based on data from 2014, concluded that there was no association between congenital anomalies and external radiation exposure doses.

*1 Fujimori K, et al. Fukushima J Med Sci 2014
*2 Yasuda S, et al. J Epidemiol 2022

These sessions are intended to share the latest results and findings of the Fukushima Health Management Survey with public health nurses and public health and welfare officials of the 13 municipalities in restricted areas and areas under evacuation orders (Hirono Town, Naraha Town, Tomioka Town, Kawauchi Village, Okuma Town, Futaba Town, Namie Town, Katsurao Village, Iitate Village, Minamisoma City, Tamura City, Kawamata Town, Date City), to promote a better understanding of residents' health status and encourage better health habits.

The sessions include time to gather questions and opinions about the Fukushima Health Management Survey, along with various requests regarding health issues of the residents and responses from municipalities. We respond to these requests and/or expectations to the best of our ability, and this has led us to the implementation of health seminars or other health-related events in each municipality.

Guided by Fukushima Health Management Survey findings, the Center provides advice, recommendations, and human resource development to 13 municipalities in restricted areas or former evacuation zones as needed to ensure that the findings benefit society at large. The Center also strives to maintain and promote the health of individual residents by explaining the results of each survey at periodic meetings in the 13 municipalities and by holding health seminars hosted by the Center.

This symposium has been held to disseminate the latest Fukushima Health Management Survey results, and to share those results, and insights gained, with a global audience through discussions among domestic and foreign experts and other participants. This should contribute to our ongoing efforts to maintain and promote the health of Fukushima residents. We also aim to develop new scientific findings from the surveys.

The relationship between radiation specialists and the general public is very similar to the relationship between doctors and patients. In the past, doctors would explain things one-sidedly to patients, and that was it. These days, patients can do their own research, learn about their treatment, and consult with their doctors about their treatment plans.
However, doctors should still check that the information patients find online is correct and reliable. It's also important for doctors and patients to work together.

At our university, we are increasing the amount of time spent on radiation education classes and related activities. Even if doctors are "radiation experts" in some sense, they have a wide variety of specializations, knowledge levels, and backgrounds, through which mutual understanding and trust can be established.
Also, our university's partnership and collaboration with the IAEA can be helpful for risk communication activities related to radiation.

To improve people's awareness of the risks of radiation, it is important not only to share detailed data on the effects of radiation but also to explain things using easy-to-understand examples from everyday life. For example, you can talk about how much exposure a passenger gets on an international flight or how the level of natural radiation in your area compares to other regions.

It is also informative to measure radiation levels by yourself. This will enhance the understanding of your local situation and facilitate informed decision-making. Interpreting the data is also an important step in the process.

* For a comprehensive overview of the survey's methodology and findings, please refer to page 17 of the presentation slides of Dr. May Abdel Wahab's lecture.

The items included in health checkups are determined by local municipal governments. In this survey area (Hamadori, a coastal area in Fukushima Prefecture), the items "language" and "temper" were included since before the 3.11 disaster. Consequently, data from FY2011 are available.
The impact of the disaster on such developmental items varies. While some items have shown an increase, others have experienced a decrease. Delays in language and related areas have remained relatively high.

It was observed that the overall sense of health among parents/guardians in the Hamadori area of Fukushima Prefecture was associated with their perception of receiving insufficient support and the prolonged duration of their evacuation.

Parents/guardians in the survey area may have experienced feelings of isolation and instability due to their loss of social resources, such as the nursery school or child development support center they had been using. Additionally, transitioning to a nuclear family household, whether through a move or other changes in family structure, could affect people's ability to consult with others.

We offer information on loan programs run by the Social Welfare Council and other organizations, as well as local food banks, as needed. We facilitate connections with relevant local government offices and case workers at medical institutions.
Our goal is to extend comprehensive support, ensuring that individuals in need of support, goods, and information receive whatever assistance they need.

Since the 3.11 Great East Japan Earthquake, numerous disasters have occurred throughout Japan, including the Kumamoto earthquake, heavy rains in the Chugoku region, and the Noto Peninsula earthquake. This has led to questions regarding the ongoing presence of evacuees from the Great East Japan Earthquake and nuclear disaster. Despite the existence of adequate response systems at evacuation sites, through the Act on Special Measures for Responding to Nuclear Disasters, there are instances where local government offices may not fully comprehend these systems.

Many people affected by the nuclear disaster have evacuated while keeping their residential registration in Fukushima Prefecture, which complicates the situation for local governments. It is difficult for these governments to understand why evacuees are living in their jurisdiction while having no residential registration. An evacuees' identity is more than where they move or how they commute to work or school, so it is necessary to help them articulate their unique circumstances.
If evacuees visit a local government office but encounter difficulties receiving support, we assist or facilitate intervention by Fukushima Prefecture staff.

Our organization has been recognized by local governments as a reliable contact point, based on the support we provided after the Great East Japan Earthquake, and we are often the first people they call when there is a need for disaster-related support.

To solve the problems of people seeking support, we need to connect them to resources in the communities where they live. So, building daily connections within their local community is very important.
It is important to build relationships that are visible in each community while making use of several projects, such as disaster case management and the development of a multilayered support system for social welfare.

As time goes on, issues will keep changing. For example, after 10 years, some people will be in need of nursing care. So, it is most important to build a system in each community to deal with issues that change over time.

There are persistent negative images of radiation based on Japan's history and the Fukushima Daiichi nuclear power plant accident. A significant proportion of individuals residing outside Fukushima Prefecture continue to express concerns regarding potential genetic effects of radiation in the region.
On the other hand, doctors who treat cancer patients with radiation say that in such cases, the risk of untreated cancer is greater than the risk of radiation, to which patients often reply, "I don't understand radiation, but I trust you, so I think I should do what you think is best." This stands in contrast to the situation where individuals fear radiation due to a lack of understanding, as seen during the nuclear power plant accident.

When considering this, the way the general public reacts to radiation is strongly influenced by their anxiety, fear, and distrust of authorities. So, it's important to understand the real reasons behind their worries.
If you tell someone who feels that "Fukushima is not safe enough" that "the radiation in Fukushima is not a problem, "their anxiety will not be resolved. Instead, if you sincerely listen to their concerns and build a relationship of trust, their perspective on radiation may change.

If you provide a supportive presence and facilitate a two-way dialogue with your friends, addressing their concerns and offering reassurance, they may gradually come to set aside their fears.While scientific knowledge is certainly important, relationships of mutual trust may be of even greater significance.

Public health nurses and other municipal staff have reported a significant decrease in inquiries from residents regarding radioactive materials, environmental dynamics, and food. This decline is noteworthy, especially when considered against the high volume of such inquiries immediately following the NPP accident. These issues are rarely a problem these days. Situations vary in each of the 13 municipalities; for example, the situation and response to the return of evacuees also seem to differ.

Efforts are underway to establish periodic briefing sessions that can provide individualized support through site visits to each municipality, during which session leaders will ascertain each municipality's particular needs and disseminate FHMS results and related information.

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