The 3rd Congress of the Japanese Association for Radiation Accident/Disaster Medicine was held on August 29, 2015 (Saturday) at Fukushima Medical University. The theme, “Seeking the ways of cooperation among institutes,” attracted approximately 200 delegates.
According to the prospectus, the association was newly established in 2013 in response to the nuclear accident of TEPCO’s Fukushima Daiichi (hereafter nuclear accident), and its base was “Radiation Accident Medical Research Society,” which was founded to make recommendations, and carry out verification from the standpoint of radiation emergency medicine and radiation hazards. Below is the summary of the congress.
1. Opening remarks
Prof. Choichiro Tase (Professor, Department of Emergency Medicine, Fukushima Medical University School of Medicine), President of the 3rd Congress, pointed out the significance of holding the congress in Fukushima, the prefecture most affected by the nuclear accident, specifically at Fukushima Medical University (FMU), considering the roles of both FMU and the association. Prof. Tase said he would like the outcome of this congress to be a signpost for the future. He also said “The Nuclear Regulatory Authority published review results of the radiation medical system at the time of the nuclear accident on August 26, and ‘advanced radiation medicine support center’ and ‘nuclear disaster medical care and comprehensive support center’ were assigned. It will require a multi-faceted approach to link past and present experiences and achievements to the future.”
2. Educational lecture I “Establishment of the new radiation medical system”
(Speaker: Kenji Kamiya, Vice-President, Hiroshima University)
The points of the lecture were two: The first was our conventional radiation medical system, and the second was our new radiation medical system. Summary is as follows:
1. The radiation emergency medical system before 2011
After the occurrence of the Tokai JCO criticality accident in 1999, the Nuclear Safety Commission assigned the National Institute of Radiological Sciences as the third radiation medical institute nationwide, with Hiroshima University covering western Japan, and the National Institute of Radiological Sciences covering eastern Japan, since 2001.
Hiroshima University has been devoted to formulating the network in western Japan, namely Kyushu, Chugoku, Shikoku, Kinki and Hokuriku.
The Fukushima nuclear power plant accident was an unprecedented combination of natural disasters with nuclear consequences. The results were beyond the assumption of conventional radiation emergency medicine, and a new radiation medical system is now required.
Lessons learned and challenges resulting from the Fukushima nuclear accident are summarized below.
1. Evacuation of residents
2. Destruction of infrastructure and dysfunction of hospitals caused by it
3. Lack of understanding of radiation medicine among hospitals staff
4. Support for people with anxiety about contamination
5. Dealing with restricted access regions
6. Development of human resources
7. Improvement of equipment
8. Development of information network
Based on these points, the government published “Nuclear Emergency Preparedness Guidelines” in October, 2012. It includes the importance of radiation medicine, placement of nuclear disaster medical coordinator(s), and addressing a complex disaster covering a wide area.
The pillars that the Nuclear Regulatory Authority has been discussing for the new nuclear emergency medical system are: nuclear disaster medical center hospitals (including nuclear disaster medical teams), nuclear disaster medical cooperation organizations (institutes, professional associations, and private enterprises), nuclear disaster medical comprehensive support centers (Hiroshima University, Fukushima Medical University, Hirosaki University, Nagasaki University), advanced radiation emergency medical support centers (National Institute of Radiological Sciences, Hiroshima University, Fukushima Medical University, Hirosaki University, Nagasaki University), and nuclear disaster medical teams.
Current expectations of the review results include the placement of centers at a national level, clarification of hospital responsibilities, nuclear disaster medical dispatch teams, improvement of education and training, and improvement of transport systems for victims. Roles and human resources for a nuclear disaster medical coordinator, roles and clarification of receiving hospitals when many people are contaminated, and roles and clarification of transport agencies remain as subsequent challenges.
3. Educational lecture II “Efforts toward health after the complex nuclear disaster in Fukushima Prefecture”
(Speaker: Akira Ohtsuru, Professor, Department of Radiation Health Management, Fukushima Medical University)
The overview of results from the Fukushima Health Management Survey were reported, including:
1. Basic Survey, to assess the external radiation exposure of ~2 million residents over 4 months post-accident;
2. Thyroid Ultrasound Examinations, to screen ~370,000 children and adolescents for thyroid disease;
3. Comprehensive Health Check for ~210,000 people from designated evacuation areas;
4. Mental Health and Lifestyle Survey for the same cohort of ~210,000;
5. Pregnancy and Birth Survey to follow ~16,000 pregnancies.
Though the basic survey is for all people in Fukushima Prefecture, the response rate of 27% has been sluggish, on the other hand, participation in thyroid ultrasound examinations has been 81%, and the response rate of the pregnancy and birth survey has been comparatively high, at 53%. This shows that people’s greatest interest has been placed on children and pregnant women. The response rates of 4 and 5 are relatively low, 31% and 33%, respectively, suggesting a need to rethink methods and approaches, especially because evacuees have spread across the country.
In addition, it is recognized that immediate countermeasures are needed for the increase of obese children (children whose body weight is 120% of standard weight or more), depression, and PTSD. It was reported that exposure to radioactive iodine was very small compared with Chernobyl, by thyroid examination.
In summary, the invisible nature of radiation leads people to form their own opinions from rumors and personal perceptions of risk. Things like anxiety, prejudice, and self-reproach must be dealt with constructively for the sake of people’s mental health and wellbeing. This is now the most important purpose of risk communication.
4. Special Lecture “Dose assessment and health risk assessment of the Fukushima Daiichi nuclear power plant accident – Overview of UNSCEAR report and the necessary research activities in the future -”
(Speaker: Gen Suzuki, Director of Clinic, International University of Health and Welfare)
UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) has been publishing reports on the dose assessment and the health risk assessment of the Fukushima nuclear accident from 2013, and a Japanese version of it was published in 2015.
According to the reports, the radiation spread by the Fukushima nuclear accident, compared with Chernobyle, are: iodine 131, about 1/10; cesium 137, about 1/5. Volatile fission products leaked in Fukushima, whereas non-volatile products leaked in Chernobyl. .
Eight of approximately 230 Fukushima nuclear power plant workers who had taken 20 or more tablets of “stable iodine prophylaxis” for more than two weeks were diagnosed with hypothyroidism.
The health risk assessments for workers in 2013 reported 1. hypothyroidism and 2. risk of cardiovascular disease as very low (threshold: 0.5 Gy); and 3. risk of cataract is low (threshold: 0.6 Gy).
In the public exposure dose assessment, “Because of the uncertainty caused by the lack of measured data, a concern is that evacuees from the same region showed 4-5 times overestimate or underestimate of dose, depending on place and time data were collected.” In addition, due to the difference in protective behavior and food habits, the exposure dose assessments showed uncertainty of 30-50% or 2-3 times. In fact, the UNSCEAR report shows overestimates compared with those based on actual measured values from thyroid examinations and whole body counters.” Excess cancer incidence, congenital abnormalities and/or genetic effects have not been observed.
The long half-lives of various radioisotopes are well established, but natural dispersion, purposeful decontamination, and individual exposure profiles make straightforward assessments and future predictions difficult.
As there exits “uncertainty” of concrete numerical figures and weather information at “the early stage of the accident,” evaluation of the prediction values is insufficient.
Multiple studies including the 2014-2016 contract research from the Ministry of the Environment (Senior Researcher: Gen Suzuki), and other research have been proceeding simultaneously, and the purpose of these studies is to clarify the “uncertainty.” By reducing the “uncertainty” that was pointed out by the UNSCEAR report, the correct dose assessment will be gained and establishment Japanese thyroid model will be achieved.
5. Educational Seminar “Pioneers who were born in Tohoku – Kiyoshi Shiga, Hideyo Noguchi, and Hachiro Ohara”
(Speaker: Yoshifumi Takeda, Vice-President, Hideyo Noguchi Memorial Foundation)
Modern medicine opened its door with Pasteur’s refutation of spontaneous generation of microorganisms (1861), the discovery of disinfection methods by Lister, and the discovery of the tubercle bacillus by Koch (1862). The contemporary achievements Tohoku-born Shibasaburō Kitazato (1853-1931), Kiyoshi Shiga (1871-1957), Hideyo Noguchi (1876-1928), and Hachiro Ohara (1882-1943) were presented.
6. Symposium “The future approach to radiation accidents and disaster – the way of cooperation among institutes”
Lectures were given by seven speakers, followed by vigorous discussion chaired by Kazuhiko Maekawa (Director, Tsuru Toranomon Surgical Rehabilitation Hospital）and Yasushi Asari (Professor, Department of Emergency Medicine, Kitazato University School of Medicine).
1.“With respect to education” – Naoyuki Yamamoto (Director, Nuclear Safety Research Association Radiation Disaster Medical Institute)
2.“As an initial exposure treatment hospital” – Genro Ochi（Department Director, Anesthesiology and Emergency Services, Yawatahama City General Hospital）
3.“Approach by University of Fukui as a secondary radiation medical institute” – Takeshi Obuchi (Specially Appointed Assistant Professor, University of Fukui)
4.“Radiation emergency medical support team” – Yoshihiro Yamaguchi (Professor, Department of Emergency Medicine, Kyorin University School of Medicine)
5.“Activities of the Central Nuclear Chemical Weapon Unit at the Fukushima Daiichi nuclear power plant accident” – Isao Watanabe (Risk Management Department, Fukushima Prefecture)
6.“Advanced radiation medical support center” – Shingo Akashi (Executive Board Member, National Institute of Radiological Sciences)
7.“About accident victims’ support among emergency workers in a nuclear facility” – Shojiro Yasui (Deputy Director, Office for Radiation Protection of Workers, Occupational Safety and Health Department, Ministry of Health, Labor and Welfare)
7. Closing Remarks
Dr. Tase, president of the congress, said that the various presentation and discussion formats of the congress helped attendees exchange and share meaningful information that is critical to advance the objectives of the association.