The Basic Survey was designed and launched to acquire baseline data to protect and promote the health of everyone in Fukushima at the time of the nuclear accident. The external radiation doses received due to the Fukushima Daiichi Nuclear Power Plant accident are estimated by asking survey participants to complete a questionnaire about their behavioral records during the first four months following the accident. This is the most practical way to estimate external exposure doses for each individual from the time when air dose rates were highest.

External exposure doses are evaluated by combining behavioral records from the Basic Survey Questionnaire with dose rate maps from radiation monitoring data collected by the Ministry of Education, Culture, Sports, Science and Technology (MEXT)*.

* For the three days from March 12 to March 14, when the monitoring data published by the MEXT was not available, calculations were made using the data on the amount of radioactive materials released by then the Nuclear and Industrial Safety Agency (NISA) in June 2011 and using the System for Prediction of Environmental Emergency Dose Information Network System (SPEEDI). For March 15, calculations were made using the same data as that of March 16, and for March 16 and after that day, we used the monitoring data published by the MEXT.

The dose estimation based on the current and available technology would not be as accurate as direct measurement. Now, it is possible to measure external doses by wearing personal dosimeters, but immediately after the accident, these were not widely available. Therefore, we adopted a method to estimate external exposure doses using a program developed by the National Institute of Radiological Sciences (NIRS, now QST) based on behavioral records submitted by individuals and environmental radiation maps. This continues to be the best way to estimate external radiation doses received in the months following the accident.

Radiation dose assessment is not conducted by a single institution bearing full responsibility; rather, multiple institutions undertake different roles as part of a coordinated effort.

Concerning internal radiation exposure, examinations using whole-body counters have been conducted mainly by Fukushima Prefecture and municipalities. For further details, please refer to the Fukushima Prefecture website.

Fukushima Prefecture Website (Available only in Japanese)

In addition, regarding internal thyroid exposure immediately following the earthquake, national research institutions and other organizations have conducted studies and assessments, commissioned by the Ministry of the Environment, based on the activity records provided by residents in the Basic Survey questionnaires.

As of March 31, 2023, 99.8% of 467,256 survey respondents (excluding those engaged in radiation work) who received external dose estimates from the first 4 months after the nuclear accident received less than 5 mSv, and 93.8% were exposed to less than 2 mSv. The single highest estimate was 25 mSv.

Estimated individual doses are provided to those who submit the Basic Survey questionnaire. In addition, doses for each municipality were posted in newspapers for a while after the Fukushima Nuclear Power Plant accident.
We continue to provide the Fukushima Prefectural Oversight Committee with up-to-date data from the Fukushima Health Management Survey.

The Basic Survey is the only way to know one's external radiation exposure doses for the four months immediately after the nuclear power plant accident, when air dose rates were highest.
In addition to informing individuals about their external radiation exposure doses, Basic Survey information can be shared with our Center to guide how we monitor your health over the next 10, 20, and 30 years.

The Basic Survey is still ongoing. We can provide you with an estimated external radiation exposure dose whenever you return the Basic Survey questionnaire.
If you have lost your questionnaire, please contact us for another copy.

Verification of internal radiation exposure doses has been done with whole-body counter examinations conducted by Fukushima Prefecture and its commissioned institutions. The overall results are available on the Fukushima Prefecture website (available only in Japanese). The level of radiation exposure for most Fukushima residents is less than 1 mSv.

Internal exposure doses to the thyroid are evaluated by analyzing behavioral records obtained through the Basic Survey, together with the concentrations of radioactive materials in the air and tap water, obtained by computer simulation.

The method considered to be most reliable for evaluating internal radiation exposure doses to the thyroid is to directly measure radioactivity in the thyroid at a relatively early stage after the nuclear accident. This has been done for about 1,000 people, for whom the measurements have been generally consistent with estimates derived from their Basic Survey data. Therefore, we have confidence in the method that combines behavioral records from the Basic Survey with computer simulations of how radioactive substances were disbursed after the nuclear accident.

Apart from breathing air and drinking tap water, radioactive intake was limited by the following factors: the disaster occurred in March, when there were not many freshly grown vegetables available; food distribution was promptly controlled; the main focus of the assessment was children; and most importantly, the results of our assessment method and the most reliable method of direct measurement of the thyroid were generally in agreement. Since Survey-based results are generally consistent with the most reliable method of directly measuring radioactivity in the thyroid, we used doses from air inhalation and tap water intake to make our determination. This approach has been independently peer-reviewed as a prerequisite to publishing our method and results in respected academic journals.

Regarding the validity of our evaluation of external radiation exposure dose estimates in the Basic Survey, our method has been peer-reviewed by outside experts as part of the process of publishing academic papers in respected scientific journals.
Another reason to be confident is that our method of evaluating external exposure doses by superimposing maps based on behavioral records and actual measurements of air dose rates gives results that are largely consistent with results obtained through UNSCEAR's method, which estimates the external radiation exposure doses based on the measured deposition of radionuclides in the soil.

The results of the Basic Survey (external exposure dose assessment) are periodically reported to the Oversight Committee, and the reports include not only the average external radiation doses, but also the maximum values are reported.
Based on that report, the dose estimation results of the Basic Survey are evaluated by the Oversight Committee.

Internal exposure dose evaluations of the thyroid (based on mean values in each location) for one-year-old children in 16 municipalities around the Fukushima Daiichi Nuclear Power Plant ranged from 1.3 mSv (Date City) to 14.9 mSv (Odaka Ward, Minamisoma City). For more information, please refer to the research paper link below.

• Estimation of children’s thyroid equivalent doses in 16 municipalities after the Fukushima Daiichi Nuclear Power Station accident

In addition, the external exposure dose to the thyroid gland (for four months after the accident) was evaluated by multiplying the external exposure dose evaluated in the Basic Survey by 1.1. Therefore, it is evaluated as the same dose reported in the "Summary report of the Basic Survey," which was published as material for the Oversight Committee.

In Fukushima, no consistent dose-effect relationship, such as an increase in thyroid cancer detection rates with increasing radiation doses, has been observed since the nuclear accident.
Conversely, an increase in thyroid cancer detection has been observed in Hiroshima and Nagasaki atomic bomb survivors exposed to much higher radiation doses than those in the aftermath of the Fukushima nuclear accident. The results from Fukushima are not contradictory to those from Hiroshima and Nagasaki.

The Basic Survey covers approximately four months following the accident, from the time of the accident until July 1, 2011. Recalling and documenting one’s activities over this period was already challenging, and it would have been even more difficult to accurately recall activities over a longer period. In addition, surveys using personal dosimeters began to be conducted by local municipalities around September 2011. For these reasons, the period covered by the radiation dose estimation was set at four months.

In recent years, the number of responses to the Basic Survey questionnaire has declined. Therefore, there have been no new findings regarding the distribution of estimated external radiation doses.

Radiation dose assessment is not conducted by a single institution bearing full responsibility; rather, multiple institutions undertake different roles as part of a coordinated effort.

Concerning internal radiation exposure, examinations using whole-body counters have been conducted mainly by Fukushima Prefecture and municipalities. For further details, please refer to the Fukushima Prefecture website.

Fukushima Prefecture-Whole-body counters

In addition, regarding internal thyroid exposure immediately following the earthquake, national research institutions and other organizations have conducted studies and assessments, commissioned by the Ministry of the Environment, based on the activity records provided by residents in the Basic Survey questionnaires.

Both external and internal radiation exposure involve exposure of the body to radiation. The key factor is the amount of radiation received. When the radiation dose is the same, the health effects are considered to be of a similar magnitude, regardless of whether the exposure is external or internal.

Estimated doses have limitations compared with direct measurements. Today, individual external radiation exposure can be directly measured using personal dosimeters. However, such measurements were not feasible for individuals immediately after the accident.

The Basic Survey therefore estimated external radiation doses based on each individual’s activity records and environmental radiation dose data, using a computer program developed by the National Institute of Radiological Sciences (NIRS; at that time). This method was considered the most appropriate approach available under the circumstances.

There are currently no plans to revise the maps of ambient radiation dose rates used for dose estimation in the Basic Survey.

For March 12–15, 2011, when monitoring data published by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) were unavailable, different data sources were used. For March 12–14, estimates calculated using the System for Prediction of Environmental Emergency Dose Information (SPEEDI), based on radioactive material release data published by the Nuclear and Industrial Safety Agency (NISA; at that time) in June 2011, were used. For March 15, the data for March 16 were used. From March 16 onward, monitoring data published by MEXT were used.

In FY2015, approximately 3,000 individuals were randomly selected from among those who had not yet responded to the Basic Survey questionnaire. Their radiation doses were estimated and compared with those of respondents from the same areas who had already completed the questionnaire.

The results showed that the radiation dose distributions were comparable between the two groups. This confirmed that the radiation dose distributions compiled and published by the Basic Survey are representative of the situation across Fukushima Prefecture.

Yes. Both statements represent assessments by the Fukushima Prefectural Oversight Committee for the Fukushima Health Management Survey.

The statement that health effects were “not observed at a level that could be confirmed with statistical significance” was used in the Interim Report on the Fukushima Health Management Survey issued in March 2016. The statement that health effects due to radiation “are unlikely” appears in the latest Oversight Committee document, dated July 2025.

The thyroid gland is a small organ located in the neck, below the Adam's apple. It needs iodine, an essential nutrient found in food and other substances, to produce thyroid hormones. Thyroid hormones play an important role in promoting growth and development and keeping the body's organs active.

The Fukushima Daiichi Nuclear Power Plant accident that followed the Great East Japan Earthquake raised concerns about the effects of radiation. One of the reasons for this concern was the report of thyroid cancer among children effected and caused by internal exposure after the 1986 accident at the Chornobyl (Chernobyl) Nuclear Power Plant.

In Fukushima Prefecture, 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. However, thyroid examinations are being conducted to watch over children's health over the long term.

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

There are two steps of thyroid examinations: primary and confirmatory.

The primary examination is performed using an ultrasound (echo) device, also commonly used during pregnancy to visualize a fetus. The thyroid gland is examined by holding a probe coated with jelly against the base of the neck. This is painless -- no needles are used -- and takes only a few minutes. The ultrasound monitor displays anatomic structures underneath the probe, from which images of the thyroid gland can be saved and printed, to record the presence, location, size, and number of thyroid cysts and nodules.

If a cyst larger than 20.1 mm or a nodule larger than 5.1 mm is found, a confirmatory examination is recommended. The confirmatory examination includes more detailed ultrasonography, blood tests, and urinalysis, and, depending on the results of the examination, fine-needle aspiration cytology (FNAC) may be suggested to collect thyroid cells to examine under a microscope.

Eligible persons can be examined at schools, public facilities, and other general venues in Fukushima Prefecture, as well as at participating hospitals and medical institutions within and outside Fukushima Prefecture.

Examinations are offered every two years until the age of 20, then every five years, e.g., at age 25, 30, etc.

Participation is voluntary. Thyroid examinations have disadvantages as well as advantages, which are shared with prospective participants so they can make an informed decision to participate, or not.

Thyroid cancer is usually indolent, especially when it occurs in young people. Small thyroid cancers tend to be asymptomatic. If a thyroid cancer grows, the neck may swell or the affected person may have difficulty swallowing.

Surgery is the main treatment for thyroid cancer, and is usually successful. After treatment, patients can have the same kind of life as they did before treatment. In some cases of small, indolent cancers that are asymptomatic, patients can be examined periodically by a medical specialist instead of proceeding directly to surgery.

Thyroid Ultrasound Examinations conducted from the preliminary baseline survey (first-round) through the fifth-round full-scale survey (i.e., examinations conducted from FY2011 through FY2022) were evaluated by the Thyroid Examination Evaluation Subcommittee of the main Oversight Committee established by Fukushima Prefecture for detailed analysis of thyroid examinations.

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.

We have established criteria that institutions must meet to ensure the accuracy of thyroid examinations. These criteria include having a specialist accredited by at least one of the following academic societies: the Japan Thyroid Association, the Japan Association of Endocrine Surgery, the Japan Society of Ultrasonics in Medicine, and the Japan Endocrine Society (Pediatrics). Alternatively, a specialist can be accredited by completing a qualification examination administered by the Fukushima Prefecture Thyroid Examination Support Joint Committee.

In areas where few institutions conduct TUE, such as the Aizu and Minamiaizu regions, we are working to set up and schedule examinations more often, at public facilities.
We will continue with efforts to increase the number of institutions conducting examinations, as well as to conduct more examinations at public venues for examinees' convenience.

The Kaplan-Meier method of statistical analysis that we use covers participants who have undergone at least one examination or those registered in the cancer registry who can be followed up. The number of such people is decreasing over time. The baseline number of participants (at the start of follow-up) is not disclosed.
Regarding the grouping of exposure doses, this is determined by subject matter experts in the Thyroid Examination Evaluation Subcommittee. Subsequent analysis is performed as directed by the Subcommittee.

* Presentation slide 22 - Cumulative detection rate of malignant or suspected malignancy

The radiation exposure doses for TUE participants are estimates calculated from behavioral records obtained in the Basic Survey. We have confidence in the estimates because they are calculated using a method that has been peer-reviewed and published in the international scientific literature.

Based on data released by the Thyroid Examination Evaluation Subcommittee, no statistically significant relationship between radiation exposure dose and thyroid cancer detection has been identified thus far.

Currently, there is no scientific evidence of an association between thyroid cancer and radiation exposure in Fukushima following the disaster. However, respondents to a questionnaire survey conducted by Fukushima Prefecture included people who would like to continue receiving checkups. We believe it is important to ensure that those who wish to participate in TUE can continue to do so.

Yes, age brings an increased risk of developing thyroid cancer, with or without known risk factors such as obesity or smoking. Going forward, it will continue to be important to analyze the circumstances associated with thyroid cancer onset.

As you point out, the analysis of survey results is subject to confounding factors and other biases, so we are proceeding with analytic methods with expert guidance from the Thyroid Examination Evaluation Subcommittee.

As TUE continues at the request of residents, it is part of normal medical care. We believe that TUE also contributes to general health by helping to detect and prevent other diseases among TUE participants.

The type of cancer referred to in this question is cancer that progresses very slowly. Even when cancer develops in the thyroid gland, it generally has little direct impact on the body unless it metastasizes to other organs or causes problems by compressing or invading structures in the neck, such as blood vessels or the trachea. If such cancer is treated, one possible consequence is that total thyroidectomy requires lifelong thyroid hormone replacement. However, for many cancers detected at an early stage, partial thyroidectomy is possible, and in many such cases, patients can be cured without the need for hormone replacement.

Currently, ultrasound images and findings from all medical institutions that perform the primary examination, both within and outside Fukushima Prefecture, are sent to Fukushima Medical University, where they are reviewed and assessed using a standardized process. Therefore, in principle, there should be no significant differences in the quality of examinations among examination sites.

To date, we have promoted understanding by developing and distributing explanatory pamphlets for elementary and junior high school students. We have also conducted outreach classes that provide general information about medical services, including an introduction to ultrasound equipment, while promoting knowledge about the thyroid gland. In addition, to encourage greater interest and understanding, we have been using animated videos, including those available on YouTube, to explain the advantages and disadvantages of thyroid examinations in an easy-to-understand manner.

The Thyroid Examination Evaluation Subcommittee estimates internal radiation doses by matching a database of radionuclide concentrations in the atmosphere and on the ground surface, calculated using atmospheric dispersion simulations, with records of individuals' movements documented in the Basic Survey questionnaire.

Not only in Chornobyl but also at exposure levels of several tens of millisieverts or lower, thyroid cancer occurs at a certain rate irrespective of radiation dose.

In this analysis, the population is divided into four groups, or quartiles, with approximately equal numbers of individuals in each group based on the estimated radiation doses, to evaluate the potential effects of dose. Therefore, areas within the evacuation zones with higher exposure doses are classified into the highest quartile, and the potential effect on cancer detection is calculated based on the estimated exposure doses of individuals in that quartile.

Statistical analysis is essential in scientific research, and conclusions cannot be drawn while disregarding the results of statistical analyses. If radiation dose were actually associated with the rate of cancer detection, a dose–response relationship would be expected to be observed consistently across analyses conducted from various perspectives.

However, the series of analyses conducted by the Thyroid Examination Evaluation Subcommittee of the Oversight Committee has not demonstrated a consistent association. Therefore, at present, the findings do not provide evidence supporting an association between radiation dose and the rate of cancer detection.

In general, the causes of cancer are often unknown. For thyroid cancer, factors such as gender and age are known to be associated with its occurrence, but the detailed causes of thyroid cancer other than radiation exposure remain unclear. It is a fact that examinations detect thyroid cancers before symptoms become apparent. Therefore, it is considered that these cancers are being diagnosed at an earlier age than they would normally have been diagnosed. At present, however, it is not possible to determine whether these cancers would have remained without symptoms or effects on survival throughout the individual's lifetime, or whether they would eventually have caused harmful effects.

Nevertheless, fine-needle aspiration cytology (FNAC), which is used to diagnose thyroid cancer in the Thyroid Ultrasound Examination program, is performed in accordance with guidelines issued by relevant medical societies to make appropriate diagnoses while limiting overdiagnosis. Decisions regarding surgery are also made based on criteria established by relevant medical societies, and a system is in place to avoid unnecessary surgery.

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.

Municipalities have inquired about specific measures to reduce the high rates of heart attack and stroke, along with ways to address obesity among adult males, and strategies to enroll adult males in health guidance classes.

Analysis reports summarizing the results of health examinations are used to identify health issues and guide health policies in municipalities, thereby contributing to the maintenance and promotion of health among residents.
In addition, our Center is working to enhance health awareness among participating residents by dispatching staff to hold health seminars and give lectures. This serves to inform residents about trends in health checkup results and suggest preventive measures.

Yes, we have initiated follow-up studies on gender differences in diabetes onset due to psychological burden, including gender differences in diabetes complications and life expectancy.

Since this Survey covers residents of the 13 municipalities in the evacuation zone, we cannot evaluate residents outside this area to the same extent.
In general, psychological burden affects the development of diabetes regardless of whether or not a person has evacuated, so we cannot rule out the possibility that the presence or absence of psychological burden also affected residents outside the 13 municipalities in the evacuation zone.

The possibility of such a reverse causal relationship is indeed a question worthy of evaluation with the help of CHC data.

When a person experiences stress, levels of adrenal cortical hormones such as cortisol increase, which may increase the risk of diabetes.

Two factors may explain the differences between men and women. First, women may be more likely to express and report stress, whereas men may have greater difficulty doing so. Second, women may be more likely to cope through social interaction, while men may be more likely to suppress or endure stress. Consequently, the physical effects of stress may be more pronounced in men.

Lifestyle-related diseases have increased among evacuees in recent years, with obesity particularly associated with an increased risk of kidney and cardiovascular diseases. Persistent risk factors such as hypertension, hyperglycemia, dyslipidemia, obesity, and smoking may contribute to disease onset. It is therefore important to ensure that residents understand these risks and know how to improve their health.

To this end, information from the Fukushima Health Management Survey should be shared with municipal officials, public health nurses, registered dietitians, and other personnel to provide ongoing community-based guidance and support. As participation in health checkups has declined in recent years, collaboration with municipalities should also be strengthened to reach residents who have not undergone Comprehensive Health Check.

There have been few long-term, continuous investigations of lifestyle-related diseases following disasters. In this regard, the Comprehensive Health Check conducted as part of the Fukushima Health Management Survey has been highly significant.

The 15 years of data indicate that changes in the living environment, particularly those associated with evacuation, can substantially affect the development and progression of lifestyle-related diseases.

A key challenge, however, is effectively communicating these findings in ways that encourage healthier behaviors. Rather than providing one-sided advice, it is important to offer planned, gradual support tailored to each individual's circumstances and the relationship established with the person receiving support.

Fukushima Medical University provides health seminars, including lectures on lifestyle-related diseases and exercise classes, as well as public lectures for residents, at the request of the 13 municipalities whose residents are eligible for the health checkups.

For information about participation, please contact your local municipality.

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.

As for the impact on children of school shutdowns due to COVID-19, our telephone support team reports that many of those who called for assistance reported that their children were constantly playing video games at home, and that parent-child fights and sibling rivalries had increased. Many respondents reported that their children were frustrated and clashed with each other because family members were together day and night due to school shutdowns and remote work.
In the 3.11 Disaster, there were situations where parents' anxiety influenced their children, suggesting that anxiety, because they could not see an end in sight, was also common during the COVID-19 pandemic.

During telephone support, many respondents stated that they were not satisfied with their sleep compared to before the 3.11 disaster. Among them, many expressed anxiety about their future lives, including concerns about work, returning home, and the ongoing COVID-19 pandemic.
Therefore, sleep quality should continue to be monitored closely.

Although tools such as chat are very effective for delivering support to large groups of people, implementation is difficult due to issues such as manpower and system construction. However, we would like to consider it.

A paper derived from the KOKOKARA Survey describes the characteristics of those without places or persons to consult. According to the research, the following characteristics tended to be associated with having nowhere or no one to consult: being male, being middle-aged, being financially disadvantaged, being a person living alone, being elderly, and living outside the prefecture. For more information, please see the paper abstract below.

• Vulnerability of Evacuees Having No One to Consult after the Fukushima Nuclear Disaster: The Fukushima Health Management Survey

We regret that we are unable to check the status of those who have not yet responded or provide telephone support to them. Therefore, we are developing methods to facilitate their response, including the option to respond online.
Additionally, given that the Survey can be disseminated to all respondents, we enclose materials such as lists of consultation resources and pamphlets.

About the prevalence of problem drinking during the COVID-19 pandemic, there has been a decrease in overall rates for both men and women, though these trends vary by age group. Therefore, it is critical to continue monitoring problem drinking by age group as well as overall.
Furthermore, the ongoing pandemic has led to a notable rise in problematic drinking among residents who live outside the prefecture, and we assist with this through our telephone support.

* Presentation slide 14 - Proportion of those suspected of problematic drinking by gender

Resilience is commonly described as "supple recovery," which conveys an image of bending rather than breaking or snapping under stress. What is bent by stress can gradually return to its original shape.

The percentage of high-risk individuals in general health, which has been decreasing since the 3.11 disaster, increased in the COVID-19 pandemic, but only slightly. Given the number of individuals who have experienced mental health issues due to the pandemic, it is crucial to continue monitoring the situation, in part to be sure that we are not underestimating any health problems.

* Presentation slide 15 - Proportion of adults at high risk of general mental health problems, based on K6

Regardless of their circumstances, we strive to listen attentively and respond with empathy so that each person feels comfortable speaking openly. At the same time, some individuals experiencing psychological distress may not recognize signs of distress in their own physical or mental health and may continue to push themselves too hard. Therefore, based on the information provided in the MHLS questionnaire, we confirm factors such as medical care received, sleep status, and the availability of someone to consult, in order to better understand each individual’s situation.

And, based on these findings, we make a comprehensive assessment of each individual’s circumstances. In particular, for those at high risk of mental health problems, we place great importance on identifying and not overlooking signs of a potential crisis. When necessary, we provide guidance on when to seek medical care and, in collaboration with public health nurses in municipalities and other relevant organizations, take an approach that emphasizes ongoing monitoring and support.

Immediately after the disaster, evacuation following the nuclear accident caused major changes in people’s lives, including changes in employment and housing, loss of community connections, and separation from family. These changes led to acute stress reactions such as insomnia, severe anxiety, and palpitations, as well as significant lifestyle changes.

Fifteen years later, although intense anxiety has eased for some, chronic stress and isolation associated with prolonged evacuation remain challenges. Some evacuees continue to struggle with social integration, concerns about the future, or conflicting feelings about returning to their former communities.

As evacuees’ circumstances vary considerably, continued support tailored to individual needs remains important.

We regard the responses themselves, including comments provided in the free-text sections of the questionnaires, as important expressions of participants’ views and experiences, and we review the responses of each individual. In addition, we have opportunities to hear participants’ views directly through telephone support, the call center, and interviews.

Regarding perceptions of the effects of radiation exposure, the survey asks not only about potential effects on future generations but also about perceived health effects on individuals who experienced the nuclear accident themselves. Specifically, individuals aged 16 years and older (general population category) have been asked, on an annual basis, about perceived health effects ranging from acute effects immediately following the accident to potential late effects, such as cancer.

The results of these questions are reported annually to the Fukushima Prefectural Oversight Committee for the Fukushima Health Management Survey.

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

In Fukushima Prefecture, depressive symptoms among pregnant women and mothers who experienced the disaster were characterized by factors such as anxiety about the potential health effects of radiation on their children and the sudden changes in their living environment associated with evacuation.

According to a study by the Radiation Effects Research Foundation (RERF) examining chromosomal abnormalities in the children of atomic bomb survivors, no significant difference in the prevalence of chromosomal abnormalities was found between children born to exposed parents and those born to unexposed parents.

Furthermore, other studies have reported no association between parental radiation exposure and the incidence of cancer, cancer mortality, or the prevalence of lifestyle-related diseases in their children.

The Fukushima Health Management Survey is also considering follow-up studies of the children included in the survey as they reach adulthood, as well as studies of potential effects on the next generation, that is, their grandchildren.

The comments included expressions of feeling depressed, requests for advice on child-rearing, concerns about radiation levels, complaints about the mother's own health problems, and requests for individual consultation and support.

According to the UNSCEAR 2001 report, Hereditary Effects of Radiation, epidemiological studies of hereditary effects among populations exposed to radiation as a result of the Chornobyl accident, including people living in highly contaminated areas of Belarus and Ukraine and populations in European countries, found no increase in the incidence of Down syndrome, congenital disorders, spontaneous abortions, or perinatal mortality.

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.

In principle, copyrights to slides and other materials belong to the authors. Except in cases permitted by copyright law, the reuse of any material generally requires permission from the original author.

Disaster-related deaths are considered those resulting from the aggravation of original injuries caused by a disaster or illnesses resulting from the physical burden caused by the evacuation, and at this point, there are no such case reports caused by direct effects of radiation exposure.

After the Fukushima nuclear disaster, we realized that our previous plan for nuclear emergency hospitals had some weaknesses.

Some of the 19 designated emergency hospitals for nuclear disasters in Taiwan are too close to nuclear power plants. If a nuclear accident happens, these hospitals may not be able to function. After the Fukushima disaster, three hospitals near the nuclear plant lost their function due to the tsunami or had to be evacuated because they were inside the emergency response zone. In Japan, some hospitals designated for nuclear disasters were not well-prepared for general disasters, meaning they could not treat regular patients. On the other hand, hospitals that could treat regular patients often could not handle patients exposed to radiation.

To address this issue, Taiwan decided that large emergency hospitals should also be able to handle patients with mild radiation contamination. However, some hospitals are resistant to this change, and efforts are still being made to push forward.

Currently, basic radiation patient management has been added as a required course for emergency doctors in training and is even included in their certification exams. The goal is to ensure that all emergency doctors have at least the basic skills to handle radiation-exposed patients and do not fear treating them.

Most importantly, the Fukushima accident showed Taiwan's medical community that worst-case scenarios can happen. We must be well-prepared to respond effectively when needed.

Taiwan has learned several important lessons from Japan's disaster response and recovery efforts:

Disaster Response
1. Disasters can be complex: The Fukushima nuclear disaster was not just a nuclear accident—it was also affected by an earthquake and a tsunami. This showed that emergency response plans may not always work as expected, so they must be flexible and continuously updated.

2. Communication is critical, and backup plans are needed: During a disaster, communication systems may fail. Japan's experience showed the importance of having multiple backup communication methods, such as satellite phones and radios, to ensure effective coordination.

3. Evacuation is much harder than in drills, especially for hospitals and nursing homes. In real disasters, evacuation is far more difficult than in training exercises. Patients in hospitals and residents in nursing homes often have mobility issues, making evacuation complicated. More detailed planning is needed to ensure their safety.

4. The psychological impact of a nuclear disaster is huge, and early risk communication is essential: After the Fukushima accident, fear of radiation affected many aspects of life, including the economy and community recovery. Japan's experience showed that clear and transparent communication about risks in the early stages of a disaster is crucial to prevent panic and misinformation.

Recovery
Recovery is a long-term process: The effects of the Fukushima disaster did not disappear quickly. Rebuilding land, industries, and communities takes many years. Taiwan has learned that disaster recovery is not just about rebuilding infrastructure; it also requires long-term social and economic support to help affected areas fully recover. These lessons have helped Taiwan improve its disaster preparedness and understand the challenges of long-term recovery.

I think that "information" is most important. Since Taiwan has very few actual radiation emergency events and limited research resources, international cooperation is very important for us. We hope to focus on two key areas:

1. Sharing real case experiences: By working with countries that have handled radiation emergencies, we can learn from their response experiences, medical treatment processes, and long-term health monitoring. This helps fill the gap in Taiwan's practical experience.

2. Innovation in radiation disaster medical science: This includes improving training methods, such as virtual reality simulations, joint international drills, and standardized guidelines for diagnosis and response. These efforts can help medical professionals improve their skills and response efficiency.

Through these international collaborations, we hope to strengthen Taiwan's ability to respond to radiation disasters and ensure a quick and effective reaction in case of an actual event.

Taiwan does have an IT emergency patient tracking system for pre-hospital care and an IT system for hospital transfers during disasters. Thank you for your suggestion—integrating radiation dose tracking into the existing system is indeed worth considering. Currently, radiation-exposed patients from nuclear power plants are documented on paper, and they are sent to designated partner hospitals. However, this process has not yet been integrated into a digital system.

Indeed, the threats facing Taiwan have increased significantly in recent years. Last year, Taiwan's Ministry of Health and Welfare launched a Resilient Medical System Plan, and one of its initiatives includes developing manuals for both surgical and non-surgical medical personnel, referencing international tactical medicine practices. These manuals are not limited to radiation-related medical staff but cover a broader range of emergency and disaster response situations.

In Taiwan, disaster medicine is a part of emergency medicine, and radiation disaster response is a subfield of disaster medicine. As I mentioned in today's talk, in 2007, while completing my emergency medicine training, I had the opportunity to receive short-term radiation disaster medical response training in Japan. After 2012, I frequently visited Fukushima and other countries to learn more, and over time, I developed an interest in this field.

Over 20 years ago, I served as a naval medical officer in Taiwan and am still in the reserve force. At that time, we did receive some basic training in nuclear, biological, and chemical (NBC) protection. However, since I have been out of active service for a long time, I am not entirely sure about the current situation. That being said, such training is likely still included in the military's preparedness programs.

As far as I know, after the Fukushima nuclear disaster in Japan, Taiwan's Nuclear Safety Commission has continued to pay close attention to related issues and has been actively learning and preparing.
Based on past experiences, such as the handling of radioactive rebar incidents in 1982, I believe the Taiwanese government would also implement similar measures.

As a medical professional, I understand that while the LNT (linear no-threshold) model remains a topic of debate in academia, in clinical practice we generally follow the ALARA (as low as reasonably achievable) principle. This means minimizing radiation exposure as much as reasonably possible without compromising diagnostic or therapeutic quality. This practical approach is, in a way, based on the idea that even low doses of radiation may carry some risk—an idea consistent with the LNT model.
While I cannot speak for policy-level decisions, this risk awareness and protective practice are certainly part of our everyday work in healthcare.

In Taiwan, under normal circumstances, the radiation dose limit for occupationally exposed workers is not to exceed 50 mSv in any single year, and the average annual dose over any consecutive 5-year period must not exceed 20 mSv, which means a total of no more than 100 mSv over 5 years.
These limits are stipulated in the Ionizing Radiation Protection Act and the Standards for Protection against Ionizing Radiation, enforced by the Nuclear Safety Commission (NSC) of Taiwan.

In Taiwan, regardless of whether a hospital is designated for radiation emergency medical response or not, medical personnel who are occupationally exposed to radiation—such as those involved in radiological procedures—are required to receive radiation protection training, especially if they need a radiation safety license as mandated by the Nuclear Safety Commission.

For radiation emergency medical response, the Ministry of Health and Welfare has commissioned the Taiwan Society of Emergency Medicine's Disaster Medical Education Center to provide free training courses across different regions. These courses are publicly announced and open to all hospitals—designated or not— with no mandatory participation. Interestingly, in recent years, participation from non-designated hospitals has been even higher than from designated ones.

In Taiwan, coordination and information sharing between local governments and medical institutions during a nuclear emergency are carried out under the Nuclear Emergency Response Act and related regulations. The Central Emergency Operations Center issues instructions based on the situation, and local emergency response centers—usually led by city or county governments—are responsible for implementing protective actions, including the distribution of KI tablets. Medical institutions are not the primary units responsible for KI distribution; this task is handled by the local public government. However, if a hospital is assigned a role in the regional emergency response plan, it may assist during emergencies by providing support or medical consultation.

In general, medical institutions focus on public education, health advice, and assisting local authorities, but they do not directly manage the storage or distribution of KI tablets.

What I would like to emphasize is that scientific knowledge about the dose–risk relationship at low doses has continued to accumulate. This does not mean that the risk has increased, but rather that we are better able to quantify and assess it. Nevertheless, considerable uncertainty remains at low doses. Even if an association between radiation exposure and cancer risk exists, the attributable risk is considered to be extremely low.

In Fukushima, most residents were exposed to very low doses. Therefore, even a slight increase in risk would be extremely difficult to detect through epidemiological studies. Studies conducted over the past 10–20 years involving several hundred thousand to approximately one million people have likewise shown that risks at low doses are very small or difficult to detect.

Overall, it is reasonable to consider the risk of thyroid cancer in the population of Fukushima Prefecture to be very low. While a small number of individuals may have received somewhat higher doses, their contribution to the overall population-level risk is considered to be extremely small.

In children, thyroid cancer and leukemia have the strongest established associations with radiation exposure. Their dose–risk relationships are more readily observed, and their shorter latency periods make them useful indicators when evaluating radiation health effects.

For other cancers, however, it is difficult to clearly demonstrate effects at low doses, and individual epidemiological studies alone cannot provide definitive conclusions.

Therefore, rather than making definitive assessments for specific cancers, it is important to conduct surveillance, such as monitoring cancer incidence in specific populations, and to provide information based on these findings.

The Fukushima Health Management Survey includes health examinations with blood cell counts, while Japan also has an established cancer registry system. Information on radiation dose distributions from the Basic Survey can be compared with cancer registry data to further evaluate potential associations.

Research on the potential effects of radiation exposure on diseases other than cancer, including cardiovascular disease and neurocognitive function, has progressed in recent years. However, compared with cancer, these effects remain less well understood and should be interpreted with caution.

Over the past 20 years, researchers have examined potential associations between radiation exposure and these diseases, as well as possible biological mechanisms. However, no definitive conclusions have been established.

For example, radiation exposure may be one risk factor for cardiovascular disease, but it is not considered a major cause. Lifestyle factors such as diet, physical activity, smoking, and cholesterol levels have a much greater influence.

Thus, radiation exposure is one of many risk factors, and its contribution is considered relatively small. Its effects should be assessed in the context of other major lifestyle-related risk factors, without either overestimating or underestimating them.

First and foremost, I would like to emphasize the importance of continuing the efforts. The Fukushima Health Management Survey is highly valuable because it has provided objective data continuously over an extended period.

A major strength of the Survey is its systematic, long-term collection of data from populations with different evacuation experiences and levels of radiation exposure. This provides an important basis for objectively assessing how radiation exposure and changes in living environments may affect health.

Such longitudinal data are valuable not only for monitoring the health of Fukushima residents but also for preparing for future nuclear accidents internationally.

The lessons from Fukushima are particularly important in determining what epidemiological studies should be conducted after an accident, who should be responsible for them, and how potential health risks should be assessed. I hope this experience will contribute to similar efforts not only in France and Europe, but also around the world.

Research on the health effects of atomic bomb radiation has been conducted for approximately 80 years. At the time, little was known about radiation effects, but long-term studies gradually identified acute effects and diseases that develop years after exposure, particularly cancer.

Long-term studies by the Atomic Bomb Casualty Commission (ABCC) and the Radiation Effects Research Foundation (RERF) provided important evidence of increased cancer risk. A key lesson from Hiroshima and Nagasaki is that long-term health monitoring is essential for understanding the health of populations exposed to radiation.

Based on this experience, the Fukushima Health Management Survey was established following the nuclear accident, drawing on the experience of Hiroshima and Nagasaki as well as the expertise of epidemiologists. Thus, the lessons from Hiroshima and Nagasaki have served as an important foundation for the Survey in Fukushima.

Fukushima Medical University and the RERF have agreed to cooperate, providing a framework for mutual collaboration. Radiation accidents are extremely rare, and the atomic bombings were tragic historical events that should never have occurred.

However, there are commonalities in the experiences of those affected, including health concerns related to radiation exposure, and there are many areas where the two institutions can collaborate.

We hope to continue working together to develop initiatives that can contribute to the health and well-being of residents.

At the RERF, research began in 1950, and clinical studies were subsequently added. These clinical studies, known as the Adult Health Study, have followed the development of diseases other than cancer over the long term.

These studies have identified increased risks of conditions such as cataracts, thyroid disease, chronic liver disease, and hyperparathyroidism, a relatively rare condition.

In recent years, research has also advanced on the effects of radiation exposure on cardiovascular disease. Thus, the health effects of radiation beyond cancer have been investigated continuously over many decades.

Many of the challenges we face are common to those seen after previous disasters. However, the quality of subsequent support can be greatly influenced by differences in the mental health and psychiatric care systems and support networks that were in place before the disaster.

For example, following the Great Hanshin-Awaji Earthquake, Akashi City, which was located relatively close to the epicenter, already had an established system in which the local government and community residents worked together to support people with mental health conditions. As a result, local stakeholders indicated that they did not need a dedicated mental health care center because they were able to respond to the needs of their residents themselves. Consequently, they did not establish such a center. This example illustrates that when existing local networks are functioning effectively, community-based support can be provided by local communities themselves.

In contrast, in areas such as the Soso region of coastal Hamadori in Fukushima Prefecture, where support systems were relatively limited before the disaster, establishing the support infrastructure itself has been a major challenge. The nature of the disaster is also an important factor. In the case of the Great East Japan Earthquake and the Fukushima nuclear accident, a particularly significant issue was the large number of people who evacuated outside the affected areas. Support systems in evacuation destinations were not always adequate, and their vulnerability has been identified as an important challenge. A similar issue was seen after the Great Hanshin-Awaji Earthquake, when people who moved from Kobe to other areas also had difficulty accessing sufficient support.

Thus, following a large-scale disaster, disparities in the quality of support between the affected area and areas outside it can be an important challenge. Effective coordination across local government boundaries is therefore essential.

In my experience, there was a case involving a person who had lost a family member in the earthquake and had carried the grief for many years. News coverage of the Great East Japan Earthquake triggered an overwhelming emotional response, leaving the person unable to cope and eventually leading them to seek medical care. This suggests that there are still people who have endured psychological suffering for many years without seeking support.

Some survivors also continue to struggle with grief following the loss of family members. When a death occurs as a result of a natural disaster, there can be social pressure to accept the loss as something that has to be endured or moved on from. However, accepting a sudden and unexpected death is not easy.

And some people continue to carry this grief for many years. Even 30 years after the earthquake, there are still survivors who continue to receive outpatient mental health care for difficulties related to their loss.