Radiological Protection of People and the Environment in the Event of a Large Nuclear Accident

Comments on　”ICRP PUBLICATION 1XX

Radiological Protection of People and the Environment in the Event of a Large Nuclear Accident

Update of ICRP Publications 109 and 111”

2019/10/24

Yutaka Hamaoka

Faculty of Business and Commerce, Keio University

hamaoka@fbc.keio.ac.jp

(Japanese version is attached at the end of English version.)

1.1　Summary of Comment

　I would like to thank the members of ICRP TG 93 and Committee 4 who participated in the preparation of this publication, and TG 84 for their efforts in summarizing the issues at the initial stage of the accident at the Fukushima Nuclear Power Plant, which is the premise of the publication.

              The lowering the reference level is highly commendable because it could reduce radiation exposure to the general public. On the other hand, there are major limitations in the draft, for example, (1) Unclear positioning of this publication, (2) Lack of fact-finding on Fukushima and Chernobyl, (3) Ineffective Decision-Making framework that could lead to underestimation of the effects of radiation exposure, (4) Biased citations and misinterpretation of citation, and (5) Changes form Pub 109 & 111 and their reasons are not explained that obstructs stakeholder participation.

There are also undetermined problems, such as health effect of radiation in Fukushima. 12 years have passed since ICRP 103 (Recommendation of 2007), and it is time to revise the recommendation itself. In fact, revision related projects such as TG 79 on effective doses, TG 91 on low doses-rates effects, TG 102 on detriment calculation methodology, TG 112 on emergency dosimetry, and TG 114 on reasonableness and tolerability that are also incorporated in this draft, are under way. Twelve years have passed since ICRP 103 (Recommendation of 2007), and it is time to revise the recommendation. Update/Application of Publication 111 & 109 should be postponed until completion of related projects.
              After the general comment in this chapter, I comment on each part of the draft in the next chapter that will be submitted separately.

(1) Unclear position of the publication
              The title of the draft says "Update of ICRP 109 and 111", thus we assume ICRP 109 and 111 will be revised and replaced. However, the main text states that while “109 and 111 dealt with nuclear disasters and radiation emergencies in general, this publication focused on Large Nuclear Accidents. (line 193 -197)" The subtitle is also "Radiological Protection of People and the Environment in the Event of a Large Nuclear Accident." If this is the case, the existing 109 & 111 is valid even if this publication is issued because it includes situations not covered by this draft[1]. Therefore, the title should be "Application of ICRP 109 & 111 to Large Nuclear Accident".
              On the other hand, as summarized in “Table 3.1. Reference levels for emergency responders.” and “Table 6.1. Reference levels for optimization of the protection of people in the case of nuclear accidents.”, it appears that changes to reference levels have been made. If this is the case, the ICRP 103 (Recommendation of 2007), which is the premise of ICRP 109 & 111, should also be revised. Moreover, Since ICRP 103 published in 2007, there have been a number of papers in which significant risk coefficients have been obtained with an average exposure of less than 100 mSv (for example, Richardson et al. 2015; Leuraud et al. 2015). In a recent survey of epidemiological studies, NCRP (2018) concluded “Most of the larger, stronger studies broadly supported an LNT model. Furthermore, the preponderance of study subjects had cumulative doses <100 mGy (NCRP 2018, p.6)”. Upper limit of the reference level for the emergency situation should be lowered. Other reference levels should be lowered accordingly.

The position of this publication should be clarified, but as will be described later, the facts are not sufficiently described that leads to ineffective recommendations. The revision of Pub 109 & 111 should be postponed.

(2) Lack of fact-finding on Fukushima and Chernobyl
              The purpose of this publication is “Line 190 (5) The purpose of this publication is to integrate in a single document both the Chernobyl and Fukushima experience” to Publications 109 and 111. However, the draft does not fully recognize the limitations in response by the government, experts and TEPCO in Fukushima. As described in Background (1.1. Background), the draft is prepared based on Task Group 84 report (ICRP _ TG 84 2012) that summarizes the issues identified during the 1-year period (emergency phase) following the 2012 accident, thus the draft does not cover the limitations that have subsequently emerged in the medium or long term (intermediate/long term phase). The following issues should be added to ANNEX B FUKUSHIMA and the publication should be revised including measures to resolve them. Please refer to the report of the National Diet Investigation Committee, (NAIIC 2012, Ch.3), which summarizes the problems of the response of the Prime Minister's Office, the government, TEPCO, etc. for approximately 1 year after the accident. In addition, ANNEX should include at least the following.

• *The Japanese government did not take "Systematic approach" for radiation protection. For example, an annual dose of 20 mSv was used to determine the planned evacuation zone, in the use of schoolyard immediately after the accident[2], and in the lifting of the evacuation zone. This standard remains in place for 8 years after the accident. This is not in systematic accordance with the ICRP recommendation to lower the lower limit of -100 -20 mSv in an emergency and the lower of 1-20 mSv in an existing exposure over time. As for the protection strategy, ICRP 109 & 111 also describes permanent relocation permanent locations, but the Japanese government puts too much emphasis on the repatriation policy. In addition, very few stakeholders participate in decision-making.
• *Tokyo Electric Power Co., which is in charge of the release of radioactive substances from the nuclear accident, has not fully acknowledged its responsibility for the accident and has taken insufficient measures, such as compensation payments and decontamination. As a result, the company's responsibility has been placed on the shoulders of residents and consumers nationwide.
• *Limitations of “co-expertise” is not recognized. Based on experience in ETHOS in Chernobyl and Fukushima, “co-expertise” process is recommended in the publication. I partly agree importance of self-help activity. However, considering the origin of their activities, it is impossible to affirm everything. Although ANNEX A. CHERNOBYL does not mention ETHOS at all, ICRP Publication 111 "ANNEX A. 6. Chernobyl/Commonwealth of Independent States" states that residents' self-help activities originated from the inability to obtain compensation from the government due to worsening economic conditions or the collapse of the former Soviet Union. In other words, the purpose of the activity was to make residents take responsibility for what the companies and the government responsible for the accident should do. This is an extremely important fact and should be mentioned in ANNEX A of  the draft. Moreover, the evidence for the effectiveness of co-expertise is based solely on subjective and qualitative descriptions by the participants of the activities, such as Lochard (2019) and Ando (2016, 2019). Recommendations should be based on studies quantitatively assessed by third parties.
• *Some experts rejected the LNT adopted by the ICRP that caused confusion to the public and the loss of trust in experts.

(3) Ineffective Decision-Making framework that leads to underestimation of the effects of radiation exposure
 "2.2. Consequences of a large nuclear accident" was not included in Pub 109 & 111. As for the contents, ICRP 103, 109 & 111 stated that not only radiation-induced health effects but also societal and economic concerns should be taken into consideration. In the draft, "Consequences for fauna and flora", "Psychological concerns" and "Health impacts of changes in lifestyle" are added. However, no specific decision-making method to incorporate these factors is not described.
              ICRP 101 (ICRP 2006) introduces methods such as Cost-benefit analysis, Cost-effectiveness analysis, and Multi-attribute utility analysis. To evaluate alternatives to these methods, each consequence must be listed and they are evaluated quantitatively. In addition, their importance must be assessed. However, it is not clear how to measure, for example, the societal consensus, nor how to assess the relative importance of radiation exposure to potential health effects. Thus, the feasibility of proposed decision method is low. Actually, such methods have not been applied in Fukushima.
 The proposed decision-making method that considering various consequences other than the effects of radiation exposure leads to further underestimating the effects of radiation exposure.

 (4) Biased citations and misinterpretation of citation
              As for the descriptions of each section, the "2.2. 5 Psychological Consequences" cites papers on Fukushima such as Suzuki (2015) and Maeda (2017), but the "2.2. 1.2 Cancer and inheritable diseases" does not cite any papers on Fukushima.  Similarly, the evidence for the effectiveness of co-experts is based solely on subjective and qualitative descriptions by the participants in the activities, such as Lochard (2019) and Ando (2016, 2019). Recommendations should be based on studies quantitatively assessed by third parties. Thus, the cited literature is biased.

              In addition, the paragraph (B 42) states that "The first and second rounds of the thyroid ultrasonic examinations were completed in March 2014 and 2016, respectively. Children will continue to have ultrasonic examinations result increasingly until they reach 20 years of age, and every 5 years after. Childhood thyroid cancer cases found in Fukushima Prefecture are unlikely to be the result of radiation exposure after the accident." Base of the sentence is not indicated. Citation must be clearly indicated for each section. I assume FMU 2016 at the end of the paragraph is the source. The cited report only mentions the first round and it also says, "However unlikely, the possibility of the radiation effects cannot be completely denied at this point in time. (FUM 2018, p. 11)" thus the description in the draft is incorrect.

              The rationale for "Line 1930) In this regard, a long-term thyroid health monitoring programme should only be conducted for those individuals exposed in utero or during childhood or adolescence with 100 – 500 mGy absorbed dose to the thyroid." is considered to be the IARC report, but Togawa et al. (2018) that summarized the report is cited. The IARC report emphasizes that "Lastly, the Expert Group would like to stress that this report is not an evaluation of the thyroid health monitoring activities that were implemented after the past nuclear accidents, and does not include any recommendations related to thyroid health monitoring activities currently in progress, in particular the Fukushima Health Management Survey. (IARC(2018), p.16)", thus this should not be included in the draft.

              The source of reference to "(22) There is reliable scientific evidence that whole-body exposures on the order of ≥ 100 mSv," which is the premise of the reference level of 100 mSv, is ICRP 103 (Recommendation of 2007). As described previously, studies that obtained significant risk estimates at lower doses have been published. ICRP 103 should be revised based on the latest epidemiological studies.
              There are problems not only in the way of quoting but also in the interpretation of the citations. Careful citation and understanding of cited article are the basis of scientific discussion. The draft must be carefully re-examined this point.

(5) Changes form Pub 109 & 111 and their reasons are not explained that obstructs stakeholder participation
              Although ICRP 103 (Recommendation of 2007) describes the major changes in EXECUTIVE SUMMARY, the draft does not. It obstructs both understanding of the draft and stakeholder participation.

For example, explanation of reference level in Publication 109, 111 and the draft are compared in Table 1. The draft seems to lower 1-20mSv band to 1-10mSv band. However, the reason is not explained. It also adds "the actual distribution of doses in the population," "the tolerability of risk," and “exposure to levels on the order of 1 mSv per year.” The reasons are not clearly explained again. Although upper bound seems to be lowered, the draft added “the order of” to 1 mSv per year, thus in the long-term, total exposure could exceeds 20mSv. There is also no description or definition of tolerability. Major changes should be listed and the reasons of changes must be explained to promote stakeholder participation to publication formation process.

              As mentioned here, there are major problems in the draft and related projects have not reached conclusions. Thus, the revision of 109&111 should be postponed until completion of related tasks.

Table1　Comparison of Explanation of Reference Level in Publication 109, 111 and the Draft

Note) New or additional descriptions are highlighted with underline.

1.2 Matters to be added to the Publication
              Among the matters mentioned in the preceding section, the following points must be added to the publication.

*Clarification of that ICRP adopt the LNT model
              As mentioned above, in the Fukushima accident, it was misinterpreted that radiation exposure less equal 100 mSv is not harmful. In spite of ICRP 103 specifies that ICRP use of LNT, ICRP 109 & 111 and the draft do not state the use of LNT. To avoid future confusion, it should be clearly stated that ICRP adopt the LNT model.

*Unsystematic radiation protection policy of the Japanese government
              In April 22, 2011, "Areas where the cumulative dose may reach 20 mSv within 1 year from the accident were designated as Deliberate Evacuation Areas"[3]. This seems to have chosen the lower limit of the reference level of 20-100 mSv in ICRP 109. On the other hand, the same standard of 20 mSv is applied to the use of schoolyards in April 2011 and the lifting of the evacuation zone. If the lifting of the Evacuation Area is considered to be a transition to existing exposure situation, it deviates from the ICRP 109 recommendation that the lower level of 1-20 mSv band should be selected. These are described in the (Para B7, B9, B 28) of the draft. The ICRP 109 (Para y) states that the reference level will be lowered as the dose is reduced. On the contrary, the Japanese government maintains the reference level until now: 8 years after the accident.
              In addition, it downplays stakeholder participation in decision making, which is emphasized in ICRP 109 & 111. On this point, Ando (2016) says: "numeric 'lines' are set by central and local government standards (Ando 2016, p. 76)". Moreover, the Japanese government was reluctant to disclose information from the beginning of the accident, as it underestimated the accident by calling it a “core damage” rather than a “core meltdown.” In Chernobyl, thyroid screening was performed on 350,000 children, but in Fukushima, it was performed on only 1080 children, and the reason why it was discontinued is unknown. In addition, with regard to radiation protection measures, it emphasizes the promotion of return and neglect support for voluntary evacuees. In this way, the Japanese government's radiation protection is not systematic.

*Clarifying the responsibility of the company responsible for the nuclear accident
              Large scale nuclear accident occurs in a power plant operated by an electric power company. Therefore, the company should be fully responsible for the accident response and compensation after the accident, but this is not clearly stated in the draft. For Fukushima disaster, Tokyo Electric Power Co. (TEPCO) should remove the released radioactive material in accordance with the Polluter-Pays Principle. However, in “Sun field Nihonmatsu Golf club” case that the club sued TEPCO to remove radioactive in the course and compensation, TEPCO refused to take responsibility. TEPCO has been designated as the point of contact for compensation claims, that is to say, the perpetrator of the accident assesses the compensation to the victim. Moreover, the rejection of ADR frequently occurs recently.
              The term "harmful rumors" is used, which originally means that “damage from groundless information.” On the contrary, radioactive materials were spread in Fukushima Prefecture and neighbours due to the nuclear accident, and agricultural and fishery products are contaminated. Even if this is not the case, it is natural for consumers to avoid products whose image has deteriorated. In this way, TEPCO should deal with the decline in sales of agricultural and fishery products due to the accident. However, the responsibility was passed on to consumers through the phrase "harmful rumors" (Yoshikawa 2018). As mentioned above, the Chernobyl ETHOS is originated from self-help activities for the loss of state compensation. In this way, the responsibilities of the company in charge of the nuclear accident have been obscured and affected residents and consumers have been forced to bear a heavy burden. To rectify this situation, the draft should clearly state that the companies responsible for the large-scale nuclear accident should fulfill their responsibilities.

[1] line 196 "While Publications and 111 were intended to deal with all exposure situations resulting from a nuclear accident or a radiation emergency, this publication focuses on the protection of people and the environment in the case of a large nuclear accident."

[2] MEXT ”Tentative Policy to Decide Use of School Building and School Yard in Fukushima (April 19, 2011)

http://www.mext.go.jp/a_menu/saigaijohou/syousai/1305173.htm

[3] Nuclear Disaster Response Head Quarter “Basic principle and Limitations to Reassess Zoning after completion of Step 2” ｢ステップ2の完了を受けた警戒区域及び避難指示区域の見直しに関する基本的考え方及び今後の検討課題について(案)｣　http://www.kantei.go.jp/jp/singi/genshiryoku/dai23/23_06_gensai.pdf

Reference

Ando, Ryoko (2016), "Measuring, Discussing, and Living Together: Lessons from 4 Years in Suetsugi," Annals of the ICRP, 45 (1 Suppl), 75-83.

IARC (2018), Thyroid Health Monitoring after Nuclear Accidents. https://publications.iarc.fr/Book-And-Report-Series/Iarc-Technical-Publications/Thyroid-Health-Monitoring-After-Nuclear-Accidents-2018

ICRP (2006), "Icrp 101 Part2:The Optimisation of Radiological Protection: Broadening the Process," Ann ICRP, 31 (3).

ICRP_TG84 (2012), Report of Icrp Task Group 84 on Initial Lessons Learned from the Nuclear Power Plant Accident in Japan Vis-à-Vis the Icrp System of Radiological Protection: http://www.icrp.org/docs/ICRP%20TG84%20Summary%20Report.pdf accessed 2019/8/11.

Kato, Toshiko (2019), "Re: Associations between Childhood Thyroid Cancer and External Radiation Dose after the Fukushima Daiichi Nuclear Power Plant Accident," Epidemiology, 30 (2), e9-e11.

Kikkawa, Toshiko(2018) "Preparing Crisis of Society: Assumption, Recording, Warning," Kagaku 88 (10), 980-86 (in Japanese) [吉川肇子(2018), "社会の危機に備える : 「想定」「記録」「警戒」," 科学), 88 (10), 980-86.]

Leuraud, Klervi, David B. Richardson, Elisabeth Cardis, Robert D. Daniels, Michael Gillies, Jacqueline A. O'Hagan, Ghassan B. Hamra, Richard Haylock, Dominique Laurier, Monika Moissonnier, Mary K. Schubauer-Berigan, Isabelle Thierry-Chef, and Ausrele Kesminiene (2015), "Ionising Radiation and Risk of Death from Leukaemia and Lymphoma in Radiation-Monitored Workers (Inworks): An International Cohort Study," The Lancet Haematology, 2 (7), e276–e81.

NAIIC (2012), The Official Report of  the Fukushima Nuclear Accident Independent Investigation Commission: http://warp.da.ndl.go.jp/info:ndljp/pid/3856371/naiic.go.jp/en/report/ Accessed 2019/8/12

NCRP (2018), Commentary No. 27  – Implications of Recent Epidemiologic Studies for the Linear-Nonthreshold Model and Radiation Protection: NCRP.

Ohira, T., H. Takahashi, S. Yasumura, A. Ohtsuru, S. Midorikawa, S. Suzuki, T. Fukushima, H. Shimura, T. Ishikawa, A. Sakai, S. Yamashita, K. Tanigawa, H. Ohto, M. Abe, S. Suzuki, and Group Fukushima Health Management Survey (2016), "Comparison of Childhood Thyroid Cancer Prevalence among 3 Areas Based on External Radiation Dose after the Fukushima Daiichi Nuclear Power Plant Accident: The Fukushima Health Management Survey," Medicine (Baltimore), 95 (35), e4472.

Richardson, D. B., E. Cardis, R. D. Daniels, M. Gillies, J. A. O'Hagan, G. B. Hamra, R. Haylock, D. Laurier, K. Leuraud, M. Moissonnier, M. K. Schubauer-Berigan, I. Thierry-Chef, and A. Kesminiene (2015), "Risk of Cancer from Occupational Exposure to Ionising Radiation: Retrospective Cohort Study of Workers in France, the United Kingdom, and the United States (Inworks)," Bmj, 351, h5359.

Suzuki, Shinichi, Satoru Suzuki, Toshihiko Fukushima, Sanae Midorikawa, Hiroki Shimura, Takashi Matsuzuka, Tetsuo Ishikawa, Hideto Takahashi, Akira Ohtsuru, Akira Sakai, Mitsuaki Hosoya, Seiji Yasumura, Kenneth E. Nollet, Tetsuya Ohira, Hitoshi Ohto, Masafumi Abe, Kenji Kamiya, and Shunichi Yamashita (2016), "Comprehensive Survey Results of Childhood Thyroid Ultrasound Examinations in Fukushima in the First Four Years after the Fukushima Daiichi Nuclear Power Plant Accident," Thyroid, 26 (6), 843-51.

Togawa, Kayo, Hyeong Sik Ahn, Anssi Auvinen, Andrew J. Bauer, Juan P. Brito, Louise Davies, Ausrele Kesminiene, Dominique Laurier, Evgenia Ostroumova, Furio Pacini, Christoph Reiners, Sergey Shinkarev, Geraldine Thomas, Mykola Tronko, Salvatore Vaccarella, and Joachim Schüz (2018), "Long-Term Strategies for Thyroid Health Monitoring after Nuclear Accidents: Recommendations from an Expert Group Convened by Iarc," The Lancet Oncology, 19 (10), 1280-83.

Tsuda, Toshihide, Akiko Tokinobu, Eiji Yamamoto, and Etsuji Suzuki (2016), "Thyroid Cancer Detection by Ultrasound among Residents Ages 18 Years and Younger in Fukushima, Japan: 2011 to 2014," Epidemiology, 27 (3), 316-22.

(Japanese version)

”ICRP PUBLICATION 1XX

Radiological Protection of People and the Environment in the Event of a Large Nuclear Accident

Update of ICRP Publications 109 and 111”へのコメント

2019/10/24

濱岡 豊

慶應義塾大学商学部

hamaoka@fbc.keio.ac.jp

1.1　コメントの概要

このPublication作成に携わったICRP　TG93, Committee 4および､その前提となる福島原発事故の初期段階での課題をまとめたTG84の各メンバーの努力に感謝する｡

Reference level の引き下げは､一般公衆の放射線被曝を減らす方向であり高く評価する｡一方で､(1) このPublicationの位置づけの不明確さ､(2) Publication作成の前提としての事実認識の不足､(3)他のリスクを導入することによる被曝影響の過小評価につながる不十分な評価枠組､勧告の実効性の低さ,(4)引用文献の偏りや誤り(5)Pub 109&111からの変更点やその理由が明示されずstakeholderが意見を表明しにくいことなど大きな問題がある｡福島における健康被害など確定していない問題もある｡

 ICRP103(2007年勧告)から12年が経過し､勧告そのものの改訂にとりかかる時期である｡実際､このドラフトでも援用されている実効線量の見直しに関するTG79､低線量･率に関するTG91､Detriment Calculation Methodologyに関するTG102､Emergency Dosimetryに関するTG112､Reasonableness and Tolerabilityに関するTG114などのプロジェクトが進行中である｡それらに基づいて､2007年勧告を改訂した後､Pub109&111を改訂すべきである｡

　以下､この章で全体的なコメントGeneral Commentを述べた後､次章でPublicationの各文にコメントする｡

(1)このPublicationの位置づけの不明確さ

　タイトルにはUpdate of ICRP 109 and 111 とあり､109と111が改訂されreplaceされるものと考える｡しかし､本文(line 193-197)には､109と111が核災害､放射線緊急事態全般を扱ったのに対して､このPublicationは､”Large Nuclear Accident”にfocusしたとある[1]｡サブタイトルにも､”Radiological Protection of People and the Environment in the Event of a Large Nuclear Accident”とある｡そうであれば､既存の109&111は､このPublicationでは扱われていない状況も含んでいるので､このpublicationが発行されても有効である｡よって､”Update of ICRP Publications 109 and 111“ではなく､”Application of ICRP 109&111 to Large Nuclear Accident”とすべきではないか｡

　一方で､”Table 3.1. Reference levels for emergency responders.”､”Table 6.1. Reference levels for optimisation of the protection of people in the case of nuclear accidents.”にまとめられているようにReference levelsの変更も含まれているようである｡

その後､平均被曝量100mSv以下を分析対象として､有意な係数が得られている論文は多くある(例えば､Richardson et al.(2015)､ Leuraud et al.(2015)｡NCRPの最近のレポートでもこのことを認めている｡“Most of the larger, stronger studies broadly supported an LNT model. Furthermore, the preponderance of study subjects had cumulative doses <100 mGy (NCRP 2018,p.6)”｡よって､100mSvを緊急時の参照レベルの上限とすること自体を見直す必要がある｡

　このように､Publicationの位置づけを明確にすべきであるし､後述するように事実把握が不十分であることや実行可能性が低い内容となっている｡ICRP103(2007年勧告)から12年が経過し､勧告そのものの改訂にとりかかる時期である｡関連するプロジェクトや改訂が終わるまで､109&111の改訂は延期すべき｡

(2)福島やチェルノブイリの事実把握の不足

  このPublicationのpurposeは Chernobyl and Fukushimaの経験を(Publication 109と111に)統合することであるという[2]｡しかし､ドラフトでは､政府や専門家､そして東京電力の対応における課題が充分に認識されていない｡

　背景(1.1. Background)で記述されているように､今回の改訂は､ICRP Task Group 84のレポート(ICRP_TG84(2012)で指摘された､放射線防護実施上の課題issuesへの対応が中心となっているようである｡このレポートは2012年という事故後1年間(emergency phase)で認識された課題をまとめており､その後､明らかとなった中期もしくは長期段階 (intermediate/ long term phase)における問題点をカバーしていない[3]｡以下に指摘する､これらの課題をANNEX B　FUKUSHIMAに加筆し､それらを解決する方策を含めてPublicationを改訂すべきである｡なお､国会事故調の報告書(NAIIC(2012)Ch.3には､事故後約1年間の官邸､政府､東京電力等の対応の問題点がまとめられているので参照されたい｡この他､少なくとも以下の点をANNEXに含めるべきである｡

･日本政府が､放射線防護に“体系的な取り組み”を行っていないこと｡例えば､計画的避難区域の設定､事故直後の校舎･校庭の使用[4]､避難区域の解除のいずれにも年間20mSvを用いており､事故後8年経過してもこの基準のままである｡これは緊急時は20-100mSvの下限､現存被曝時には1-20mSvの低い方､それを時間とともに引き下げるというICRPの勧告に体系的に従ってはいない｡また､防護戦略に関して､ICRP109&111では永久移転permanent locationも記述されているが､日本政府は帰還政策に偏重している｡さらに､意思決定時にstakeholderをほとんど参加させていない｡

･原発事故にともなう放射性物質排出の責任者である東京電力が､事故の責任を十分に認めず､賠償や除染などに不十分な対応しかしていない｡このため､同社が負うべき責任が､被災住民や全国の消費者の負担に帰されている｡

･”co-expertise”の問題点｡住民の能動的な活動については賛同する部分もある｡これは､チェルノブイリや福島でのETHOSを念頭においたと考えられるが､その活動の起源を考えると､すべてを肯定することはできない｡ANNEX A. CHERNOBYLではETHOSについて､まったく述べられていないが､ICRP Publication 111 "ANNEX A.6. Chernobyl/Commonwealth of Independent States”によると､住民らのself-help活動は､経済状況の悪化､旧ソ連の崩壊などによって補償が得られなくなったことが起源だという｡つまり､事故の責任企業や国が行うべきことを住民に担わせるためのものであった｡これは極めて重要な点であるので､ANNEX Aにも加筆すべきである｡チェルノブイリでは事故後5年の線量が5mSv以上の地域では移住を認めたが､福島ではそうしていない｡それぞれの事例について詳細に記述し､さらに二つの地域を比較することも重要である｡

･専門家の中にも､ICRPが採用しているLNTを否定する者､100mSv以下ではリスク係数が有意ではないことを影響がないと誤解する者などがおり､これが専門家への信頼を失う大きな要因となったこと｡

(3)放射線被曝の影響の過小評価につながり､最適化の実行可能性も低い意思決定の枠組み

　"2.2. Consequences of a large nuclear accident"はPub109&111になかった項目である｡内容に関しても､ICRP103､109&111では､放射線による健康影響Radiation-induced health effectsだけでなく､Societal consequences､Economic consequencesを考慮すべきとしたが､改訂案では､さらに”Consequences for fauna and flora” ､”Psychological consequences” ､”Health impacts of changes in lifestyle”が加えられている｡しかし､これらを考慮して､どのように評価するのか､具体的な手法が明示されておらず､実行可能性が低い｡

ICRP101(ICRP(2006)では､Cost–benefit analysis､Cost-effectiveness analysis､Multi-attribute utility analysisなどの手法が紹介されている｡これら手法を用いて評価するには､各consequenceを列挙し､(定量的)に評価する｡さらに､それらの重要度も(定量的に)評価する必要がある｡しかし､例えばSocietal consequence にある､”a collapse of trust in experts and authorities(Line 378)”をどのように(定量的)に測定し､さらには放射線被曝による健康影響の可能性と比べた重要度を評価する方法が明示されていない｡実行可能性は低く､少なくとも福島では､そのようなことは行われてはいない｡

各節の記述についても､"2.2.5. Psychological consequences"では､Suzuki(2015)とMaeda(2017)など､福島を対象とした論文が引用されているが､"2.2.1.2. Cancer and heritable diseases"では､福島に関する論文はまったく紹介されていない｡福島での甲状腺検査の結果について､地域差がないとするOhira et al.(2016; Suzuki et al.(2016)､有意な地域差があるとするTsuda et al.(2016)､外部線量と有意な相関があるとするKato(2019)などがある｡後述するように､これに関して､改訂案 (Para B 42) では､不適切な引用および解釈を行っており､放射線被曝の影響を過小評価している｡提案されている意思決定の方法は､放射線被曝の影響以外の様々なconsequenceを考慮させることによって､放射線被曝の影響をさらに過小評価する方策となっている｡

(4)引用文献の偏りや引用方法､誤った解釈

　前述のように､福島についてpsychological consequenceについての論文は紹介されているが､被曝影響についての論文は本編では､まったく引用されていない｡同様にCo-expertiseの有効性の根拠としては､ICRPのLochard(2019), Ando(2016, 2019)のように活動の当事者が主観的､定性的に記述したもののみである｡推奨するのであれば､第三者が定量的に評価した研究に基づくべきである｡このように､引用されている文献には偏りがみられる｡

            さらに､パラグラフ(B 42)では､"The first and second rounds of the thyroid ultrasound examinations were completed in March 2014 and 2016, respectively. Children will continue to have ultrasound examinations biennially until they reach 20 years of age, and every 5 years thereafter. Childhood thyroid cancer cases found in Fukushima Prefecture are unlikely to be the result of radiation exposure after the accident."と述べているがと述べているが､引用先のレポートはthe first roundについてしか述べていない｡また､"However unlikely, the possibility of the radiation effects cannot be completely denied at this point in time. (FUM 2018, p.11)"とあり､ドラフトでの記述は誤りである｡また､"Line 1930) 　In this regard, a long-term thyroid health monitoring programme should only be conducted for those individuals exposed in utero or during childhood or adolescence with 100–500 mGy absorbed dose to the thyroid."の根拠は､IARC報告書だと考えられるが､それを直接引用せず､概要を紹介したTogawa et al.(2018)を引用している｡ IARCのレポートは"現在進行中の福島での健康調査へのrecommendationを含んでいない"と強調しているので[5]､ドラフトにも含めるべきではない｡引用方法だけでなく､内容の解釈にも問題がある｡引用方法および文献をしっかりと理解することも科学的文献の基本である｡ドラフトでは､上記の重要な点でそれが行われていない｡再度内容を充分にチェックすべきである｡

          なお､参考レベル100mSvの前提となっている､”(22) There is reliable scientific evidence that whole-body exposures on the order of ≥100 mSv”の引用元はICRP103(2007年勧告)という古い文献である｡後述するように､その後､低い被曝量でも有意なリスク係数が得られる研究が発表されている｡それら疫学研究の知見を踏まえてICRP103自体を改訂すべきである｡

(5) Pub 109&111からの変更点やその理由が明示されておらず､stakeholderの理解や参加を阻害している｡

ICRP103(2007年勧告)では､EXECUTIVE SUMMARYに主要な変更点が述べられているが､本Publicationでは､それがなされていない｡例えば現存被曝時の参考レベル1-20mSvについて109､111と改訂版の関連部分をTable 1 に示す(英語版参照)｡本Publicationでは､the actual distribution of doses in the population and the tolerability of riskが付け加えられている｡しかし､その理由は明確に説明されていない｡また､tolerabilityも説明もしくは定義されていない｡主要な変更部分を明記し､その理由を説明すべきである｡

このように､ドラフトには大きな問題点があり､関連するプロジェクトも結論を得ていない｡関連プロジェクトが修了するまで109&111の改訂は延期すべきである｡

 1.2　加筆すべき事項

　前節で述べた事項のうち､加筆すべき事項を具体的に指摘する｡

･放射線の確率的影響がLNTモデルに従うことの明示

　前述のように､福島事故の際に､100mSvまでの被曝には影響がないという誤った解釈がなされた｡ICRP103 para 36 にはLNTを採用することが明示されているにも関わらず､ICRP109&111および改訂案には､LNTを採用することが明示されていない｡今後の混乱を避けるためにも､ICRPの防護体系ではLNTを前提としていることを明示すべきである｡

･日本政府の非体系的な取り組み

2011年4月22日､｢事故発生から1年の期間内に累積線量が20ミリシーベルトに達するおそれのある地域を計画的避難区域に設定した[6]｣｡これはICRP109での緊急時の参考レベル100-20mSvの下限を選んだものと考えられる｡一方､事故直後の校庭の使用や､避難区域の解除についても同じ20mSvが基準とされている｡避難区域の解除を､現存被ばくへの移行と考えれば､1-20mSvの下方を採用すべきというICRP109の勧告からは外れている｡

ここまでは改訂案の(Para B 7, B9, B28)に記述されている｡線量の低減にともなって参考レベルを引き下げることをICRP109(Para y)では述べているが､日本政府は事故後8年経過してもそのままとしていることを指摘すべきである｡

さらに､ICRP109&111で重視されている意思決定時のstakeholderの参加を軽視している｡この点については､本Publicationで引用されているAndo(2016)は次のように述べている｡" numerous ‘lines’ are set by central and local government standards (Ando 2016, p.76)"｡

この他､日本政府は炉心溶融ではなく炉心損傷と呼ぶことによって事故を過小にみせるなど､事故当初から情報の公開には消極的であった｡チェルノブイリでは甲状腺screeningが35万人に対して行われたが､福島では､1080名にしか行われず､途中で打ち切られた理由も不明である｡さらに､放射線防護策に関して､帰還の促進を重視し自主避難者への対応を軽視している｡このように､日本政府の取り組みは非体系的である｡

･Nuclear Accidentの原因企業の責任の明示

　このpublicationがfocusするLarge scale nuclear accidentは電力会社の運営する発電所において生じる｡よって､事故対応や､その後の賠償については､電力会社が全面的に責任を負うべきであるが､このことが明示されていない｡本来ならば､Polluter-Pays Principleに則って､放出された放射性物質は東京電力が除去すべきである｡しかし､責任を拒否することすら行われている[7]｡賠償請求についても､東京電力が窓口とされ､加害者が被害者への賠償を査定する方法が取られた｡最近ではADRの拒否が多発している｡

風評被害という言葉が使われるが､本来これは根拠がない情報によって､被害を受けることを意味する｡福島県内には原発事故によって､放射性物質が拡散されたのであり､それが農水産物に含まれる可能性はある｡それがないとしても､イメージが低下したものを忌避するのは消費者の当然の対応である｡このように､事故に伴う農水産物の売上の低下については､本来､東電が対応すべきであるにも関わらず風評被害という言葉によって､責任が消費者側に転嫁された(吉川 2018)｡前述のように､チェルノブイリのETHOSも国からの補償が得られなくなったための自助活動が起源とされている｡

このように原発事故の責任者がすべきことが曖昧にされ､消費者に大きな負担が強いられている｡このことを是正するためにも､大規模原子力事故の原因企業が責任を果たすことを前提とすることをドラフトに明記すべきである｡

　(パラグラフ毎のコメントは別途投稿予定である｡)

参照文献

英語版を参照のこと｡

[1] line 196 "While Publications and 111 were intended to deal with all exposure situations resulting from a nuclear accident or a radiation emergency, this publication focuses on the protection of people and the environment in the case of a large nuclear accident."

[2] Line 190 “(5) The purpose of this publication is to integrate in a single document both the Chernobyl and Fukushima experience with respect to the radiological protection of all affected individuals and the environment.”

[3] (Para 3) “difficulties related to the quantification of exposures; interpretation of potential radiation-induced health effects; ad-hoc protection of responders; societal impacts of the evacuation of people; recognising the importance of psychological consequences; and challenges related to the rehabilitation of living conditions in contaminated areas.”

[4] 文科省｢福島県内の学校の校舎・校庭等の利用判断における暫定的考え方について(平成23年4月19日)｣

http://www.mext.go.jp/a_menu/saigaijohou/syousai/1305173.htm

[5] " Lastly, the Expert Group would like to stress that this report is not an evaluation of the thyroid health monitoring activities that were implemented after the past nuclear accidents, and does not include any recommendations related to thyroid health monitoring activities currently in progress, in particular the Fukushima Health Management Survey. (IARC(2018), p.16)"

[6] 原子力災害対策本部 ｢ステップ2の完了を受けた警戒区域及び避難指示区域の見直しに関する基本的考え方及び今後の検討課題について(案)｣　http://www.kantei.go.jp/jp/singi/genshiryoku/dai23/23_06_gensai.pdf

[7]例えば､サンフィールド二本松ゴルフ倶楽部が､ゴルフ場内に飛散した放射性物質の除去と損害賠償を東電に求めた訴訟で､東電は事故によって飛散した放射性物質は「無主物」､つまり同社には責任がないと主張した｡