Summer
Volume 24, Issue 1, 2013

News and Views

Hiroshima and Nagasaki, Japan

Hiroshima
NagasakiTable of Contents
From the Editors ......................................................................................................................................... 1
RERF News
Report on the 40th Scientific Advisory Committee Meeting, 2013 ...................................................... 1
RERF’s Third Public Lecture for Citizens Held in Hiroshima ............................................................. 4
Biosample Center Newly Established at RERF .................................................................................... 5
HICARE Dispatches RERF Chairman and Others to Radiation Exposure Medical
Care Seminar in Korea ...................................................................................................................... 5
Dr. Warren Muir of NAS Retires—New Executive Director of RERF-support Division Appointed,
by Evan B. Douple and Roy E. Shore ............................................................................................... 6
Students from the U.S. BCA and Dr. Charles J. Camarda of NASA Visit RERF ................................. 7
U.S. Journalism Students Visit RERF to Learn about Radiation for Reporting on Fukushima............ 8
Staff News ............................................................................................................................................. 8
Visiting Student Researcher ................................................................................................................ 11Award Received by RERF Scientist .................................................................................................... 12
RERF Receives Health, Labour and Welfare Minister’s Certificate of Appreciation ......................... 13
Conference and Workshop Reports
RERF International Workshop: Heavy Structural Shielding, by Harry M. Cullings .......................... 13
RERF Hosts International Workshop on Radiation and Cardiovascular Disease, by Waka Ohishi .... 17
Second International Academic Conference on Radiation Health Risk Managementin Fukushima ................................................................................................................................... 18
Interdisciplinary Education Intensive Course: A Special Training Program for Recovery from
Nuclear Accidents, by Ritsu Sakata ................................................................................................ 19
Science Articles
Impact of Smoking on Mortality and Life Expectancy in Japanese Smokers: A Prospective
Cohort Study, by Ritsu Sakata......................................................................................................... 21
Unrepairable DNA Double-strand Breaks That Are Generated by Ionizing Radiation Determine
the Fate of Normal Human Cells, by Asao Noda ............................................................................ 23
Translocations in Spleen Cells from Adult Mice Irradiated as Fetuses Are Infrequent,
but Often Clonal in Nature, by Yoshiaki Kodama ........................................................................... 24
Association between Chronic Kidney Disease and Cardiovascular Disease Risk Factors in
Atomic Bomb Survivors, by Nobuko Sera ...................................................................................... 26
Human Interest Notes
A Farewell Note with Reflections on the Last Five Years, by Evan B. Douple .................................. 28
Reflections on My Retirement, by Kazue Imai ................................................................................... 29
Facts and Figures
LSS Survivors with Unknown Doses, by Harry M. Cullings .............................................................. 30
RERF’s Views on Residual Radiation....................................................................................................... 31
Research Protocol and Publications
Research Protocol Approved in May 2012–April 2013 ...................................................................... 32
Recent Publications ............................................................................................................................. 32
Cover photographs: Liquid nitrogen tanks used to store biosamples (left); see page 5
Public lecture for citizens (right); see page 4This newsletter is published twice a year by the Radiation Effects Research Foundation (RERF;
formerly the Atomic Bomb Casualty Commission), established in April 1975 as a private,nonprofit Japanese foundation. It is supported by the government of Japan through its Ministryof Health, Labour and Welfare and by the United States through its Department of Energy (DOE),
in part by DOE contract DE-HS0000031 with the National Academy of Sciences. RERF becamea public interest incorporated foundation on April 1, 2012.
RERF conducts research and studies—for peaceful purposes—on medical effects of radiation
and associated diseases in humans, with a view to contributing to maintenance of the health andwelfare of the atomic-bomb survivors and to enhancement of the health of all humankind.
Editor-in-Chief: Harry M. Cullings, Chief, Department of Statistics
Technical Editor: Fumie Maruyama, Public Relations & Publications Office
Editorial Policy
Contributions to RERF Update receive editorial review only and do not receive scientific peer
review. The opinions expressed herein are those of the authors only and do not necessarily reflect
RERF policies or positions.
Contact: Mailing address: RERF Public Relations & Publications Office, 5-2 Hijiyama Park,
Minami-ku, Hiroshima 732-0815 Japan
Telephone: 81-82-261-3131; Facsimile: 81-82-263-7279
Internet: http://www.rerf.jp/

update 1

From the Editors / RERF News

From the Editors
Welcome to this issue of Update. The rainyseason, expected to continue until at least the endof June, is upon us here in Japan. In contrast withthe rain’s constancy, this has been a time of change
in terms of personnel, not only at RERF, but also at
the U.S. National Academy of Sciences (NAS) andthe U.S. Department of Energy (DOE).
RERF recently saw the retirement of Dr. Evan
B. Douple, who had been the Associate Chiefof Research and the Editor-in-Chief of Update
since the beginning of 2008. Reflections on histime at RERF until his retirement are included
herein. Upon Dr. Douple’s retirement, I (Harry M.
Cullings) assumed the post of Editor-in-Chief andhope to continue Update’s timely, engaging, andinformative qualities. I owe a debt of gratitude to
Dr. Douple for his careful stewardship during his
years overseeing the publication. My task is madeeasier with the able assistance of the Technical
Editor Fumie Maruyama and the staff of the Public Relations and Publications Office, headed byJeffrey L. Hart.
Two new staff members have been hired in theStatistics Department, including Dr. Young Min
Kim, whose introduction appears in this issue,and Dr. Reid D. Landes, who will join RERF
in July. Dr. Daisuke Haruta was hired on April
1 as a research scientist at the Clinical Studies
Department in Nagasaki. Dr. Kazue Imai retired
from the Radiobiology/Molecular Epidemiology
Department and offers her thoughts in this issue.
There has also been a transition at NAS, with theretirement of Dr. Warren R. Muir, who was succeeded by Dr. Gregory H. Symmes, a change that is
touched on in this issue. Dr. Joseph F. Weiss retired
from DOE after many years of dedicated service

to the managementof RERF’s operations, with the new
Program Manager for
RERF being Dr. Isaf
Al-Nabulsi.
I have been associated with NAS since I
began working in1998 for the Committee on Dosimetry for
the RERF as a postHarry M. Cullings, PhD
doctoral fellow in the
DOE program at the University of Pittsburgh,which included my first visit to RERF. I returned to
RERF in 1999 as a research scientist in the Statistics Department and have been here continuously
for almost 14 years, having become the Chief of
the Statistics Department in 2010. We hope you
will enjoy this issue, which has a new look but ispacked with the usual news and an increased number of science articles, with a short piece on
RERF’s new Biosample Center and in-depth articles
on two recent workshops that were held at RERF.

Harry M. Cullings
Editor-in-Chief

Fumie Maruyama
Technical Editor

Report on the 40th Scientific Advisory Committee Meeting, 2013
The 40th Scientific Advisory Committee (SAC)
review of RERF’s research activities was held on
March 4–6, 2013, at our Hiroshima facility. The
SAC consists of 10 scientists, five each from Japanand the United States. The co-chairs this year were
Dr. Shunichi Yamashita and Dr. John J. Mulvihill.
Dr. Yoichi Gondo of RIKEN BioResource Centerjoined the SAC with the expiration of the term of
Dr. Katsushi Tokunaga. To aid this review, two
additional experts were appointed temporarily to
the SAC—Dr. Hiroshi Sasaki, Kanazawa Medical
University, and Dr. Andrew J. Einstein, Columbia
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University Medical Center. Their insights were
extremely valuable, and it was a great pleasure for
us to work with these outstanding scholars.
RERF Chairman Dr. Toshiteru Okubo opened
the meeting and provided a warm welcome to all.
In reviewing the past year, he mentioned there had
been eight retirements and four newly hired scientists, for a net loss of four. Since 2004, there has
been an 18% loss of general staff due to mandated
reductions. He also indicated that the Information
Technology Department has introduced a virtual
desktop system, migration to virtual servers,
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RERF News
increased network security, and improved accessby mobile devices.
Next, Vice Chairman Dr. Roy E. Shore spoke
on responses to SAC recommendations and on
new research achievements. In response to the2012 SAC recommendations, RERF has proposed
policies to improve database and biosample accessboth internally and externally; we have planned aworkshop on DNA sequencing with experts fromJapan and abroad; we conduct open meetings
regarding research protocols and share research
protocol reviews as a way to educate young investigators; we have provided advice and materials to
Fukushima investigators for the development andprocedures of their large-scale cohort and havehelped them focus their scientific and public-healthquestions; we established a comprehensive Biosample Center; we instituted new procedures toensure that study datasets will be documented andpermanently stored; we have encouraged investigators to apply for external grants; because of strong
community concerns, we have spent much timeand effort to analyze our disease data in relation topossible radiation exposures from A-bomb fallout;
and we have developed collaborations with several
experts in bioinformatics.
RERF investigators published papers in several
high impact journals during FY2012, such as the
British Medical Journal, PLoS One, FASEB Journal, Radiology, and Radiation Research. A few
substantive highlights of our research publications
are: Regarding radiation exposure and cancer, we
published a major analysis of updated data on leukemias and lymphomas1; an update on thyroid cancer risk2; an analysis of radiation, lifestyle factors,
and urothelial cancer risk3; an analysis of radiation,smoking, and various histologic subtypes of lungcancer4; and the first evidence for the involvementof ALK gene rearrangements in radiation-associated thyroid cancer.5 Regarding noncancer diseases
and conditions, papers were published on radiationand cataract surgery incidence6; radiation and risk
for subtypes of stroke7; radiation, chronic kidneydisease and cardiovascular risk factors8; and theimpact of smoking on mortality and life expectancy.9
Other published reports considered radiation andsystemic markers of inflammation10; an RERF international workshop on radiation effects on somaticand germline mutations11; improved estimation of
A-bomb doses to human organs12; and the use of
tooth enamel for gamma and neutron biodosimetry.13
RERF scientists have continued their active
involvement on international radiation-protection
and risk-assessment committees, such as the ICRP
(International Commission on Radiological Protection), UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation), WHO(World Health Organization), and NCRP (National
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update 2
Council on Radiation Protection & Measurements).
They also gave a number of invited lectures abroadand have numerous collaborations with investigators at various institutions in Japan, Europe,
America, and Asia.
Turning to the 2013 SAC report, a brief statement of the key general recommendations is asfollows:• More high-quality publications in international English language journals are essential
for the continued success of RERF. An
examination of citation impact factors would
also be useful.
• Decisions about organizational structure areneeded, with regard to future hiring and purchase of large equipment.
• The SAC highly values the efforts of RERF
to date in support of activities related to
Fukushima. This unfortunate tragedy represents an ideal opportunity for delivery of
the RERF “product” and “know-how” inthat it represents transfer of RERF scientificknowledge and process knowledge (such as
consideration of low-dose radiation healtheffects and long-term follow-up) to a pressing
public concern.
• Greater attention should be given to the global
impact of RERF. Good beginnings are wellunderway with international collaborations,participation in international policy agencies,
and large research collaborations.
• Since the new Articles of Incorporation now
permit receiving donations and philanthropy
to augment the mission and effectiveness of
RERF, the SAC urges explorations of the use
and potential of this new possibility.
• The SAC applauds the effort to consolidate
and inventory all biologic specimens.
• For junior investigators, the SAC recommends a program of training for professionalradiation career development.
Selected highlights of the departmental recommendations include:• Clinical Studies Department: Research onradiation and noncancer diseases should becontinued, and strengthened by seeking active
participation of world-leading experts frominside and outside Japan as well as recruiting
young researchers.
• Radiobiology/Molecular Epidemiology
Department: The idea of applying an ontology-type approach to the genome-wide
genetic variant data is encouraged, as a similar approach has been highly successful inextracting biological meaning from geneexpression studies.
RERF Update Volume 24, Issue 1, 2013

update 3

RERF News• Genetics Department: Continue to explore thepotential use of whole-genome DNA sequencing (WGS). This will help in focusing expectations regarding WGS, framing essential scientific questions, and providing more accurate
assessment of concomitant costs.
• Epidemiology Department: Analyses of mortality and cancer incidence among the F1(children of the atomic bomb survivors)
cohort and those exposed in utero are particularly relevant and important to publish as soon
as possible.
• Statistics Department: The dosimetry changes
and their impact on the basic Life Span Study
cancer risk estimates should be completed assoon as possible so that questions about their
possible effect can be settled. Also it is criticalthat the issue of radioactive fallout exposures
receives both scientific and public-relations
attention.
In summary, the SAC highlighted the uniquerole RERF plays in determining radiation risks andthe potential for valuable continued studies. The
committee urged the prompt development and publication of new results regarding issues of scientificand public-health concern and suggested ways toaddress new technological challenges in the basic
sciences.
RERF Scientific Advisors
Dr. Shunichi Yamashita, Co-Chairperson, Vice
President, Fukushima Medical University
Dr. John J. Mulvihill, Co-Chairperson, Children’s
Medical Research Institute/Kimberly V. Talley
Chair in Genetics; Professor of Pediatrics;
Head, Section of Genetics, University ofOklahoma Health Sciences Center
Dr. Kiyoshi Miyagawa, Professor, Laboratory of

Molecular Radiology, Center for Disease Biology and Medicine, Graduate School of Medicine, The University of Tokyo
Dr. Kazuo Sakai, Director, Research Center for
Radiation Protection, National Institute ofRadiological Sciences
Dr. Kazuo Tajima, Director, Aichi Cancer Center
Research InstituteDr. Yoichi Gondo, Team Leader, Mutagenesis andGenomics Team, RIKEN BioResource Center
Dr. Sally A. Amundson, Associate Professor of
Radiation Oncology, Center for RadiologicalResearch, Columbia University Medical Center
Dr. Marianne Berwick, Distinguished Professor
and Chief, Division of Epidemiology, Associate
Director, Population Sciences, University of
New Mexico
Dr. David G. Hoel, Distinguished University Professor, Department of Medicine, Medical University of South Carolina, and Principal Scientist, Exponent, Inc.
Dr. Michael N. Cornforth, Professor and Directorof Biology Division, Department of Radiation
Oncology, University of Texas Medical BranchSpecial Scientific Advisors
Dr. Hiroshi Sasaki, Professor, Department of Ophthalmology, Kanazawa Medical University
Dr. Andrew J. Einstein, Victoria and Esther Aboodi
Assistant Professor of Medicine, Division of
Cardiology; Director, Cardiac CT Research,
Columbia University Medical Center
References
1. Hsu, W.-L., Preston, D., Soda, M. et al. The
incidence of leukemia, lymphoma and multiple myeloma among atomic bomb survivors:
1950-2001. Radiat. Res. 179, 361-382, (2013).

Participants of the 40th Scientific Advisory Committee meeting held at Hiroshima RERF
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RERF Update Volume 24, Issue 1, 2013

update 4

RERF News
2. Furukawa, K., Preston, D., Funamoto, S. et al.
Long-term trend of thyroid cancer risk among
Japanese atomic-bomb survivors: 60 years
after exposure. Int. J. Cancer 132, 1222-1226(2012).
3. Grant, E. J., Ozasa, K., Preston, D. L. et al.
Effects of radiation and lifestyle factors on
risks of urothelial carcinoma in the Life Span
Study of atomic bomb survivors. Radiat. Res.
177, 86-98 (2012).
4. Egawa, H., Furukawa, K., Preston, D. et al.
Radiation and smoking effects on lung cancer
incidence by histological types among atomic
bomb survivors. Radiat. Res. 178, 191-201(2012).
5. Hamatani, K., Mukai, M., Takahashi, K. et
al. Rearranged anaplastic lymphoma kinase(ALK) gene in adult-onset papillary thyroid cancer amongst atomic bomb survivors.
Thyroid 22, 1153-1159 (2012).
6. Neriishi, K., Nakashima, E., Akahoshi, M. et
al. Radiation dose and cataract surgery incidence in atomic-bomb survivors, 1986-2005.
Radiol. 265, 167-174 (2012).
7. Takahashi, I., Abbott, R. D., Oshita, T. et al.
A prospective follow-up study of the association of radiation exposure with fatal and nonfatal stroke among atomic bomb survivors in
Hiroshima and Nagasaki (1980-2003). BMJ

Open 2, e000654, doi:10.1136/ (2012).
8. Sera, N., Hida, A., Imaizumi, M. et al. The
association between chronic kidney diseaseand cardiovascular disease risk factors inatomic bomb survivors. Radiat. Res. 179,
46-52 (2013).
9. Sakata, R., McGale, P., Grant, E. J. et al.
Impact of smoking on mortality and life
expectancy in Japanese smokers: a prospective
cohort study. Br. Med. J. 345, (e7093) (2012).
10. Hayashi, T., Morishita, Y., Khattree, R. et al.
Evaluation of systemic markers of inflammation in atomic-bomb survivors with specialreference to radiation and age effects. FASEB
J. 26, 4765-4773 (2012).
11. Kodama, Y., Noda, A., Booth, C. et al. International workshop: Radiation effects on mutation in somatic and germline stem cells. Int. J.
Radiat. Biol. 88, 501-506 (2012).
12. Cullings, H. M. Recommended improvements
to the DS02 dosimetry system’s calculation oforgan doses and their potential advantages for
the Radiation Effects Research Foundation.
Radiat. Protect. Dosim. 149, 2-14 (2012).
13. Nakamura, N., Hirai, Y., Kodama, Y. Gammaray and neutron dosimetry by EPR and AMS,
using tooth enamel from atomic-bomb survivors: A mini review. Radiat. Protect. Dosim.
149, 79-83 (2012).

RERF’s Third Public Lecture for Citizens Held in Hiroshima
On Saturday, December 1, RERF held its third
public lecture program for citizens at the Memorial Hall in the basement of the Hiroshima Peace
Memorial Museum’s East Building, from 14:00
to 16:30. About 150 people attended. This open
lecture program was first held in 2010 to promoteexchange between citizens and RERF by providing
readily understandable information to the generalpublic including A-bomb survivors about researchachievements obtained at RERF over the years
and health effects from radiation. The program has
been held every year since then.
Following opening remarks by Chairman
Toshiteru Okubo, Mr. Kazumi Matsui, Mayor of
Hiroshima and the event’s invited guest, extended
his greetings. Two lectures followed. First, Dr.
Kotaro Ozasa, Chief of the Department of Epidemiology, delivered a lecture titled “Long-term Health
Effects of Radiation,” explaining the progress andresults of RERF’s follow-up studies of A-bomb
survivors, persons exposed in utero, and A-bomb
survivors’ children. Next, Dr. Yoichiro Kusunoki,
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Chief of the Department of Radiobiology/Molecular Epidemiology, in his lecture titled “Mechanistic

Dr. Kotaro Ozasa, Chief of Department of Epidemiology,
giving a lecture during the third public lecture program

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RERF News
Study of Health Effects of Radiation,” briefed theaudience on research into the mechanisms of radiation effects on health and the significance of suchmechanisms, as well as the changes to immune
function brought about by radiation exposure.
Thereafter, a question-and-answer session washeld on the basis of audience questions collected
after each of the lectures. Not all of the many questions could be responded to in the time available,
and thus several audience members remained in thehall eagerly asking questions even after the conclusion of the event.

Biosample Center Newly Established at RERF
RERF’s Biosample Center, newly establishedand officially incorporated into the foundation’sorganizational structure on April 1, 2013, aims at
integrated management in a systematic and accessible manner of RERF’s blood, urine, and otherbiosamples obtained from A-bomb survivors.
About 980,000 biosamples currently in the custody of RERF were previously cryopreserved andmanaged at individual research departments. Now,
RERF will keep all biosamples together undercentralized management at the Biosample Center.
The Center will be able to respond to requests fordata from outside research institutions in the future
by forming databases of such individual epidemiological data as age, sex, radiation dose, exposure
conditions at the time of bombings, and subsequent
incidence information, linking that information to
the aforementioned biosamples, and then anonymizing the data.
Center facilities were established in both
Hiroshima and Nagasaki, with Chief Scientist Dr.
Kazunori Kodama assuming the post of Biosample
Center Director and taking charge of both facilities.
The facilities have seven staff (a research scientist,

five technical staff, including two full-time members, and an administrative worker) in Hiroshima
and eight staff (a vice director, a research scientist,
five technical staff, and an administrative worker)
in Nagasaki. In fiscal 2013, RERF will proceedwith organization of the biosamples and maintenance of databases with a view to initiating fullscale operations of the Center in fiscal 2014.

Dr. Toshiteru Okubo (right), Chairman, and Dr. Kazunori
Kodama, Chief Scientist and Director of the Biosample
Center, affixing the Center nameplate

HICARE Dispatches RERF Chairman and Others to Radiation Exposure
Medical Care Seminar in Korea
On February 19, for the first time, the Hiroshima
International Council for Health Care of the Radiation-exposed (HICARE) convened the “Radiation
Exposure Medical Care Seminar” in Korea. Amonga total of four participants dispatched by HICARE
from Japan were two RERF representatives: Dr.
Toshiteru Okubo, RERF Chairman and HICARE
President, and Dr. Kazunori Kodama, RERF Chief
Scientist and HICARE Executive Secretary. Heldin Seoul, the seminar was designed for physicians,
nurses and other medical personnel who engage
in providing health care for A-bomb survivors in
Korea.
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Chairman Toshiteru Okubo (center) and Chief Scientist
Kazunori Kodama (second from left) at the seminar in Seoul

RERF Update Volume 24, Issue 1, 2013

update 6

RERF NewsHICARE has organized similar seminars in the
U.S. and Brazil, but this is the first seminar staged
jointly overseas with the Nagasaki Association for
Hibakusha’s Medical Care (NASHIM), which has
experience hosting seminars and training sessions
for Korean physicians and others.
The other two participants were Dr. Koichi
Tanigawa, Professor in the Department of Emergency and Critical Care Medicine at the Hiroshima
University Graduate School of Biomedical Sciences and HICARE Executive Secretary, and Dr.
Yasushi Miyazaki, Professor at the Nagasaki University Graduate School of Biomedical Sciences
and NASHIM Operating Committee member,
both of whom presented lectures at the seminar.
They spoke about the latest findings from healtheffects studies of A-bomb survivors in Hiroshima
and Nagasaki, and discussed responses to the
Fukushima Dai-ichi nuclear power plant accident.
Approximately 3,000 A-bomb survivors residein Korea. However, 67 years have passed since theatomic bombings, and these survivors are aging.
One goal of the seminar was to foster an environment that ensures appropriate medical care for
A-bomb survivors on a consistent basis. Anothergoal was to respond to the heightened consciousness in Korea about health effects from radiation
against the backdrop of the nuclear accident inFukushima. To accomplish these goals, HICARE
and NASHIM approached the Korea Institute ofRadiological Medical Sciences (a national radiological research institute) and the Korean Red
Cross for help in organizing the seminar. The four
HICARE representatives visited these institutes
before and after the seminar to exchange views
about the possibility of enhanced collaboration andto establish collaborative systems such as for theacceptance of trainees from Korea.
As part of the national government’s support
operations for A-bomb survivors living outside
Japan, Nagasaki Prefecture and Nagasaki City
began dispatching a medical team to Korea to provide consultation twice a year, starting in 2004. Dr.
Masazumi Akahoshi, former Chief of the Department of Clinical Studies in Nagasaki, often participated in the medical team on behalf of RERF (referto a separate article by Dr. Akahoshi regarding thisproject in RERF Update Vol. 20, Issue 2, 2009).

Dr. Warren Muir of NAS Retires—New Executive Director of
RERF-support Division Appointed
Evan B. Douple, former Associate Chief of Research
Roy E. Shore, Vice Chairman
Scientific support for RERF has been provided
after 12 years in that position.
by the National Academy of Sciences (NAS) and
Dr. Muir was recently described by NAS Presithe National Research Council (NRC) component
dent Ralph Cicerone as “a creative and energeticof the National Academies since the establishment of the Atomic Bomb Casualty Commission (ABCC) following the request signed byPresident Truman 67 years ago. That supportand involvement has been a key element inproviding independent scientific leadershipand guidance. The office at NAS responsible
for recruiting U.S. scientists to work at RERF
or to serve as advisors to RERF resided initially in the Institute of Medicine’s Medical
Follow-up Agency, later in the NRC’s Board
on Radiation Effects Research (BRER), andcurrently in the Nuclear and Radiation Studies
Board (NRSB). The NRC’s Division on Earthand Life Studies (DELS) oversees Academy
work in the environmental, life, and chemical From right, Dr. Warren R. Muir, Dr. Kevin D. Crowley (NAS), Dr. Shelleysciences, including that of NRSB and previ- A. Hearne (RERF Councilor), Dr. Roy E. Shore, and Dr. Evan B.
ously BRER. The first Executive Director of Douple at the time of the June 2010 Board of Directors meeting in
DELS, Dr. Warren R. Muir, recently retired Nagasaki
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RERF News
leader who has been a strong advocate for the roleof science in the development of public policy.” He
has been a strong supporter of RERF and annuallyattended the RERF Scientific Advisory Committee
or Board of Councilors meetings. Warren championed RERF’s mission and sought to increase its
public visibility. He was particularly interested
in the humanitarian aspect of the RERF study
since he frequently pointed out that the scientificresults potentially could benefit the survivors
and all of humanity. That interest was probably
influenced by his personal “extracurricular” workfor peace in a project in Northern Ireland andanother in Cyprus—where he has devoted considerable energy and time leading two nonprofit
organizations that promote trust, understanding,and friendship between teenage leaders from thedivided communities in the two locations. Warren
retired from NAS to his home in New Hampshireand sends his best wishes for the future success of
RERF. We at RERF will miss him.
However, we are glad for continued strong
support under new leadership. After a nationwide
search, Dr. Gregory H. Symmes was appointed as
Warren’s successor early in 2013. He was viewed
as a popular choice by many of Dr. Symmes’ NAS
colleagues, who were familiar with Greg’s strong

update 7
work ethic, pleasantand soft-spoken style,shrewd judgment, andbroad scientific experience. He received his
BA summa cum laude ingeology from Amherst
College and his PhD
in geology from Johns
Hopkins University.
Greg first joined the
NRC in 1995 and has Gregory H. Symmes, PhD
directed NRC programs
and studies on a wide range of science and technology policy issues. He had risen to the positionof Deputy Executive Director of DELS when hewas selected to be Warren’s successor. Dr. Symmes
especially appreciated his first visit to RERF toattend the Scientific Advisory Committee meetingin March of this year where he was able to receive
an overview of RERF’s studies and an update of
the most recent findings. He is looking forward
to providing assistance to RERF through DELS’
oversight of the NRSB and its Director, Dr. Kevin
Crowley, and to making himself available should
special RERF needs arise.

Students from the U.S. BCA and Dr. Charles J. Camarda of NASA Visit RERF
On November 20, two teachers and eight students from Bergen County Academies (BCA), ahigh school located in the U.S. state of New Jersey,
visited the Hiroshima Laboratory, led by teachers
from the Hiroshima Prefectural Kokutaiji SeniorHigh School, as part of the “Super Science HighSchools” project of the Ministry of Education,
Culture, Sports, Science and Technology (MEXT).
The group was accompanied by Dr. Charles J.
Camarda, of the U.S. National Aeronautics andSpace Administration (NASA), who was visiting
Hiroshima. After receiving briefings on RERF
and RERF’s recent research achievements from
Mr. Takanobu Teramoto, RERF Executive Director, and Dr. Roy E. Shore, RERF Vice Chairman,
respectively, the visitors listened to an explanation
by Dr. Yoichiro Kusunoki, Chief of the Departmentof Radiobiology/Molecular Epidemiology, aboutmechanistic research into radiation-associated disease development and also watched a demonstra-

Return to Table of Contentstion of a cell sorter (laboratory equipment used for
instant analysis of blood cell properties and DNA
statuses at the cellular level, and for high-speed
extraction of targeted cells).

BCA students watching cell sorter demonstration by Dr.
Yoichiro Kusunoki (far left)

RERF Update Volume 24, Issue 1, 2013

update 8

RERF NewsU.S. Journalism Students Visit RERF to Learn about Radiation for
Reporting on Fukushima
On March 13, two journalism students from
Indiana University (IU), located in Bloomington,
Indiana, visited the Hiroshima Laboratory. Yao
Xiao and Megan Jula belonged to a student groupfrom an IU international reporting class that had
traveled to Japan to learn about the atomic bombings of Hiroshima and Nagasaki and how RERF’s
research has been utilized in Fukushima.
Yao and Megan interviewed Drs. Eric Grant andHiromi Sugiyama of the Epidemiology Department about RERF’s findings and were provided
with an abbreviated facility tour. In Hiroshima, inthe days before their RERF visit, the two interviewed Mr. Steven Leeper, then Chairperson of
the Board of Directors of the Hiroshima Peace
Culture Foundation and former member of RERF’s
Hiroshima Local Liaison Council, and toured thePeace Memorial Museum as well as met withseveral A-bomb survivors. In Tokyo, at the startof their trip, their itinerary included meeting with
Fukushima refugees.
After returning to Indiana, both wrote to RERF
about their experience, emphasizing how muchthey enjoyed Japan and the importance of the infor-

mation obtained at RERF to the writing of theirstories. RERF strives to accommodate requests
for cooperation in educational activities. We wish
Yao and Megan the best with their projects andlook forward to seeing how their RERF experienceplays out in their future careers. We hope their visit
inspires others to contact RERF for information
related to radiation’s health effects.

Students, at left, listening to explanation about radiation's
health effects

Staff NewsAs reported in Staff News in the last issue (Vol.
23, Issue 2, 2012), Evan B. Douple, Associate
Chief of Research, and Nori Nakamura, Chief
Scientist, both retired as of December 31, 2012.
Dr. Douple, who served at RERF for five years as
a staff member of the National Academy of Sciences (NAS), returned to Washington, D.C., where
he recently was awarded at a retirement dinner
for his 20 years of work at NAS. Dr. Nakamura
was reappointed as Consultant to the Departmentof Genetics effective January 1 of this year. Yuko
Hirai, Chief of the Cytogenetics Laboratory,
Department of Genetics, and Kazue Imai, Associate Senior Scientist, Department of Radiobiology/
Molecular Epidemiology (RME), retired under the
mandatory age limit as of December 31. Dr. Hirai
was reappointed as Adjunct Specialist (researchscientist) effective January 1, in order to continue
research at the Cytogenetics Laboratory. Although
Dr. Imai returned to Tokyo, she was appointed as
Consultant to the RME Department as of January
1. Research Scientist Eiji Katsurada, Departmentof Clinical Studies (Hiroshima), resigned upon
Return to Table of Contents

term expiration as of March 31, and Masazumi
Akahoshi, Chief, Department of Clinical Stud-ies(Nagasaki), resigned effective March 31. Dr.
Akahoshi assumed the position of Deputy Director at Keiju Hospital of the healthcare association
Wakokai as of April 1, and was also reappointed as
Consultant to the RERF Department of ClinicalStudies effective May 1.
On the other hand, four new research scientists
were hired at RERF. Young Min Kim joined theDepartment of Statistics as a research scientist
as of February 12. Daisuke Haruta joined theDepartment of Clinical Studies (Nagasaki) as a
research scientist, and Masayuki Hidaka andYiqun Hu joined the Departments of Genetics andRME, respectively, as postdoctoral scientists effective April 1.
Kazunori Kodama, Chief Scientist, was concurrently appointed on April 1 as Director of the
Biosample Center, newly established as of thesame date (see related article on page 5). Tomonori
Hayashi, Assistant Chief of the RME Department,
and Misa Imaizumi, Chief of the Divisions of
RERF Update Volume 24, Issue 1, 2013

RERF News
Radiology and Clinical Laboratories (Nagasaki),were concurrently appointed as research scientistsof the Center on April 1.
In April every year, RERF presents awards toemployees for their long-term service. This year,
19 employees were awarded in Hiroshima and 10
in Nagasaki. Among them, Eiji Nakashima, Assistant Chief, Statistics Department, and Michiko
Yamada, Chief, Division of Health Examinations,
Department of Clinical Studies (Hiroshima), wereawarded for 30 years of service. Asao Noda, Assistant Chief, Genetics Department, was awarded forhis 10 years of service.
The abovementioned four new research scientists introduce themselves in the following section:
Young Min Kim, PhD
I started working for the
Department of Statistics as a
research scientist on February 12, 2013. I was born inSeoul, the Republic of Korea.
I studied statistics at Yonsei
University for bachelor’s andmaster’s degrees and obtained
a PhD last year at Iowa State
Young Min Kim
University in the USA. My
dissertation topic was nonparametric methods suchas bootstrap and empirical likelihood methods
for dependent data. I also studied kernel-based
nonparametric estimation and regression methods.
Before I joined RERF, I worked for the Departmentof Biostatistics, University at Buffalo (UB), State
University of New York as a post-doctoral associate. I have developed statistical methodologies for
Exact Tests using nonparametric Bayesian methods
and quantile regression applied to analysis of biomarker data.
Dr. Randolph Carter, a former research scientistof and currently a consultant to the RERF Statistics
Department, as well as a professor at the Department of Biostatistics, UB, introduced me to RERF,
and Dr. Harry Cullings, the Statistics Department
Chief, visited UB and told students and me in moredetail about RERF’s work. I then applied for the
position here. There were several reasons I wasinterested in RERF: 1) I had been interested inradiation effects and nuclear issues since I was afreshman at Yonsei University. However, I could
not be involved in those topics when I was studying
statistics. RERF will give me a chance to now doresearch related to these fields. 2) I had focused on
the development of theoretical statistical methodologies, not on statistical application, before I joined
RERF. Since RERF is one of the biggest suchinstitutions in the world and has a lot of data, I canwork with such real data and contribute to RERF
research with my background in various statistical
Return to Table of Contents

update 9methodologies. 3) RERF is in Japan, which is close
to my home of Korea. That means my parents are
relatively close. 4) In addition, I am interested inlearning new cultures, in particular, Japanese culture, because I am a fan of Japanese manga, books,
and TV dramas. Thirteen years ago when I was auniversity student, I thought that someday I would
learn Japanese. And now, this appears to be thetime, finally, to do so.
I am honored to have the opportunity to carry on
the research mission of RERF as a statistician anddevelop statistical methodologies related to RERF
projects. I would like to get to know the people at
RERF as soon as possible, and I look forward tolistening to everyone’s advice and guidance regarding my research and life in Hiroshima, Japan. I
appreciate your support in advance.
Daisuke Haruta, MD, PhD
My name is Daisuke Haruta,
and I joined the Department ofClinical Studies at RERF in
Nagasaki as a research scientist on April 1, 2013. After
graduating from Oita University School of Medicine in
2002, I worked at the Department of Cardiovascular InterDaisuke Haruta
nal Medicine (formerly the
3rd Internal Medicine Department) of Nagasaki
University. I then worked as a cardiovascular specialist at the Nagasaki Atomic-bomb Survivors
Hospital, Nagasaki Neurological Medical Center,
Usa-Takada Hospital, and other Nagasaki University-affiliated hospitals. In 2007, I started studying as a graduate student at Nagasaki University
as I continued to work. While in graduate school
and working as an internist, I conducted an epidemiological study of arrhythmia-related symptoms(Brugada syndrome and early repolarization syndrome) for four years as a visiting research fellow
at RERF. For this study, I spent over a year reading
50 years’ worth of ECG recordings of about 6,000
A-bomb survivors. I can still recall those days
being impressed by the long-term participation of
A-bomb survivors in the health examination program and the tremendous efforts made by RERF
staff to accumulate data. Each of the medical charts
I reviewed contained the life stories of A-bomb survivors. During those four years, I was able to experience the hardship of conducting research and thejoy of publishing a paper in a journal. These experiences were invaluable to me. I would like to takethis opportunity to express my sincere appreciation
again to Dr. Masazumi Akahoshi, former Chief ofthe Department of Clinical Studies in Nagasaki,
and other RERF staff members for their support
and cooperation.
RERF Update Volume 24, Issue 1, 2013

RERF NewsAt just about the same time that I completed
graduate school, the Great East Japan Earthquake
struck. Since the earthquake, much attention has
been focused on the Fukushima Dai-ichi nuclear
power plant accident and the health effects fromradioactive substances released as a result of theaccident. This prompted me to think that I might
be able to make a contribution to society different from my usual role as a physician engaging
in medical treatment in a clinical setting. For thisreason, I feel highly motivated to continue researchat RERF, a long-standing research organization
where I feel privileged to work as a research scientist. Being a novice in this field, my abilities arelimited; however, I am determined to make utmost
efforts to contribute to the further development of
RERF research. I look to all of you for your guidance and support.
Masayuki Hidaka, PhD
Greetings to the staff of
RERF. My name is Masayuki
Hidaka, and I joined the Laboratory of Cytogenetics in the
Department of Genetics on
April 1 this year.
I completed my doctoral
program at the Graduate
School of Frontier Sciences,
Masayuki Hidaka
the University of Tokyo, in
March 2010. In the doctoral program, I investigated DNA damage responses, such as DNA repair,
apoptosis, and cell cycle, using a radiation-sensitive mutant RIC1 strain of Japanese killifish, aswell as ATM (-/-) or p53 (-/-) killifish. This became
the focus of my PhD research. After completingthe doctoral program, I conducted research on new
virus-based cancer therapies at the Department of
Neurosurgery, the University of Tokyo Hospital. I
also examined the physical and chemical propertiesof pharmaceutical drugs and their effects on the
immune complement system at the National Institute of Health Sciences.
After obtaining my PhD, I moved away fromradiation research. However, the Fukushima
nuclear power plant accident in March 2011 mademe want to contribute to society through researchin the field of radiobiology. In thinking of possible
ways to have an opportunity to do this, I came up
with the idea of being certified as a senior radiation
protection supervisor. I passed the examination in
2012. When I informed Prof. Hiroshi Mitani, mymentor at the graduate school, of my new qualification, he kindly suggested to me that I apply for a
research position at RERF. Guided by fate, I joined
RERF.
The first scientific meeting I attended after I
started engaging in research was the annual meetReturn to Table of Contents

update 10
ing of the Japan Radiation Research Society, heldin Hiroshima in 2005. I probably have a predestined affinity to Hiroshima. Every day since I began
living in Hiroshima, I have felt thankful to the local
residents, who have been very hospitable and kindto me. The RERF staff have also been kind to me,
and thanks to their support, I have been able to
make a promising start. I intend to make efforts todeepen my understanding of radiation effects, firstby having a deep understanding of the significanceof my studies, and then by making steady progress,
step by step, to convey the outcome of the studies
to society, with the aim of contributing to “global
happiness.” I look to all of you for your guidanceand support.
Yiqun Hu, PhD
I am from Hubei provinceof the People’s Republic ofChina. The name of the province means “north of the lake,”referring to its position northof Lake Dongting, a large
lake located in neighboring
Hunan province. The climate
in Hubei is similar to that in
Yiqun Hu
Hiroshima, with four distinct
seasons. Summers are hot and humid, with punishing temperatures of 40°C or above famously associated with Wuhan, the provincial capital. The cityof Wuhan feels like a furnace in the summer.
After graduating from my university in China
with a bachelor’s degree in dentistry, I came to
Japan in 2007 to start my study abroad. It has been
almost five-and-a-half years since I first arrived in
Hiroshima, and I still remember that I had many
troubles in my studies and daily life my first year
in Hiroshima. But all of the Japanese people I met
were so kind to me. There was a volunteer who
taught me Japanese every week for free. I learned
about Japanese language and culture from her. The
most wonderful thing was that I met a very lovely
Japanese couple, who invited me to their home andfed me Japanese home cooking. Sometimes wewent out together to see the sights of Hiroshima.
I will cherish those memories in my heart forever.
Since Hiroshima is the first city that I lived in after
leaving Hubei, I consider it my second home.
After one year as a research student at Hiroshima
University, I started my PhD course under the advisors Prof. Katsuyuki Kozai (Pediatric Dentistry)
and Prof. Motoyuki Sugai (Oral Bacteriology), finishing the program in 2012. Since the work of my
PhD program focused on application of bacterialcell wall hydrolase for prevention of disease, I have
had for some time an interest in the field of molecular epidemiology. Therefore, I wanted to continue
my research in Japan even after graduation, espeRERF Update Volume 24, Issue 1, 2013

update 11

RERF News
cially in the field of epidemiology. Thanks to thehelp I received from Dr. Tomonori Hayashi, Assistant Chief, Department of Radiobiology/Molecular
Epidemiology (RME), I now have the opportunity
to continue my research as I had hoped.
I am very grateful and fortunate to be accepted
as a postdoctoral scientist at this prestigious institute of RERF. RERF has long enjoyed a good reputation in epidemiology. Thus, it will be exciting forme to do research with RERF’s renowned scientists. It is also my great honor to have the opportunity to learn many research ideas from them. I
just recently joined the Immunology Laboratory
in the RME Department on April 1. It will taketime before I am able to accomplish my mission ofcontributing to RERF’s future. In closing, I would
like to thank all of RERF’s staff and scientists, whohave accepted me warmly!

Visiting Student Researcher
Ms. Seung Hyun Hong, Research Scientist at the
National Cancer Center, Korea, underwent training
at the Departments of Radiobiology/Molecular
Epidemiology (RME) and Genetics for a period of
about two months, from January 7 to February 22,
2013. The following is her self-introduction andremarks about her training at RERF.
Seung Hyun HongI am a research scientist at the Cancer Genomics
Branch, National Cancer Center in Goyang, Korea.
Korea is a wonderful country with four different
seasons, each of them beautiful with vastly different scenery. There are very many wonderful placesin Korea, among them Jeju Island, which is registered as a UNESCO World Heritage Site.
I studied molecular biology at university. I also
finished my master’s degree in life and pharmaceutical sciences in 2011 and then joined our laboratory at the National Cancer Center. I studied about
the effects of radiation exposure and DNA damage
on carcinogenesis and immune function. I was recommended to participate in the scientific exchange
program at RERF by Dr. Joo Young Kim, Directorof the Radiation Therapy Center of the National
Cancer Center. I would like to thank RERF for giving me an opportunity to participate in this training.
During my two-month stay, I trained in various
experiments such as the effects of radiation exposure on immune function, HLA (human leukocyte

Return to Table of Contents

antigen) genotyping and FISH (fluorescence in situ
hybridization) assay at RME and the Departmentof Genetics. It was a valuable experience for me to
study and work at RERF, and I feel that the experience will play a very important role in my futurestudies.
I am very grateful for the chance I was given
here at RERF and would like to express my appreciation to the research scientists and administrative staff who have helped me during my stay in
Hiroshima, especially Dr. Tomonori Hayashi,
Assistant Chief of RME, who served as my supervisor.

Ms. Seung Hyun Hong (center) with Dr. Tomonori Hayashi(far right), Assistant Chief of RME, and Ms. Misae Sora,
Assistant Chief of Technicians, in front of the Immunology
Laboratory’s flow cytometer

RERF Update Volume 24, Issue 1, 2013

update 12

RERF NewsAward Received by RERF Scientist
Upon Receiving the Incentive Award for Young Researchers at the 24th Meetingof the Japan Geriatrics Society Chugoku-district Branch
Ikuno Takahashi, Research Scientist
Department of Clinical Studies, Hiroshima
At the 24th meeting of the Japan Geriatrics Society Chugoku-district Branch, held in
Hiroshima on November 24, 2012, I was presented
with the incentive award for young researchers.
It has already been suggested that high levelsof height loss compared to an individual’s heightin youth are associated with increased risk for
cardiovascular disease mortality, but the mechanisms behind the effects of height loss on cardiac
blood vessels are still unknown. Meanwhile, studies conducted by other research institutes recently
reported that changing patterns of blood flow
(pulse wave) in longitudinal blood vessels (large
arteries) in the trunk of the body strained the heart
and were associated with liability to cardiovasculardisease. Consequently, we reviewed the association
between the augmentation index, which measurespulse wave changes, and height loss based on the
RERF’s Adult Health Study (AHS). Our researchsuggested the possibility that height loss mightcause pulse wave changes. Based on the relevant
results, my presentation, “Review of effects ofheight loss on the cardiovascular system,” wasawarded at the aforementioned meeting.
Age-related changes in the physique are inevitable. In cases where people are prone to lifethreatening disease (cardiovascular disease) due tochanges in the physique, however, methods of preventing such disease represent an important issue.
To solve this problem, it is necessary to determine
the mechanisms behind the effects of change inthe physique upon the cardiovascular system.
However, there is a tendency to deal separately
with multiple diseases observed in one person: forexample, spinal deformity/fracture causing heightloss is categorized into the field of orthopedics,
and cardiovascular disease into the field of internal
medicine. For the purpose of deepening understanding and discovering new aspects of the mechanisms behind disease, it will become increasingly
necessary to pay attention to the big picture.

Return to Table of Contents

Dr. Ikuno Takahashi, Research Scientist, with her award

The AHS has been utilized in the study of various aspects of abnormalities in different organs to
examine the effects of radiation exposure on
human health. Without the understanding andcooperation of the AHS participants, it would
have been impossible to implement the globallyunique AHS study methods. As demonstrated by
the research described above, it might be said thatAHS is an important study not only for assessment of radiation effects but also for elucidation of
unknown mechanisms behind disease. The study
I presented at the Japan Geriatrics Society would
not have been possible without AHS, and I believethat the branch society appreciated this point,
leading to their presentation of the award to me. I
would like to express my heartfelt appreciation forsupport from the Departments of Clinical Studies
in Hiroshima and Nagasaki, the Department ofInformation Technology, and the many others who
contributed, in addition to cooperation of the AHS
participants. I hope to make further efforts to play arole in the distribution of information from RERF.

RERF Update Volume 24, Issue 1, 2013

RERF News / Conference and Workshop Reports

update 13

RERF Receives Health, Labour and Welfare Minister’sCertificate of Appreciation
RERF recently received a certificate of appreciation from the Health, Labour and Welfare
Minister for its contributions to the Ministry of
Health, Labour and Welfare (MHLW) Health Service Bureau’s projects related to the March 2011
Great East Japan Earthquake. On April 22, 2013,
Mr. Hisayuki Dehara, Chief, Atomic Bomb Survivors Support Division, Health and Welfare Affairs
Bureau, Hiroshima Prefecture visited RERF andpresented the certificate on behalf of the national
government to Dr. Toshiteru Okubo, RERF Chairman. The certificate, dated March 11, 2013, thesecond anniversary of the disaster, was awarded to
1,458 organizations in recognition of their cooperation in disaster victim support activities managed by MHLW’s Health Policy Bureau, HealthService Bureau, Pharmaceutical and Food Safety
Bureau, and Labour Standards Bureau, among others. Information about RERF’s support activities
is available in the second issue of RERF Update2011. An updated report of our support activities isalso available on the RERF website at http://www.
rerf.jp/fukushimaRERF.pdf.

Chairman Toshiteru Okubo holding the Health, Labour andWelfare Minister’s certificate of appreciation

RERF International Workshop: Heavy Structural Shielding
Harry M. Cullings, Chief
Department of Statistics
On February 4 and 5, 2013, an international
workshop was held at RERF on radiation dose
calculation for survivors who had heavy structural
shielding. Heavy structural shielding refers to concrete buildings or underground air-raid shelters.
Nearly all of the air-raid shelters were located in
Nagasaki and consisted of tunnels dug into the sideof a hill, or other, similar underground spaces. The
dosimetry systems DS86 and DS02 do not contain
modules for calculating the structural shielding ofsurvivors in such situations, and those survivors
have therefore been considered to have unknown
doses, which represent missing values for dosimetric variables in RERF analyses. (Regarding
the more general issue of unknown doses, see theFacts and Figures article in this issue of Update on
page 30.) The calculation of shielding for heavy orunderground structures involves special problems
that do not occur with light wooden structures suchas houses, for which the shielding is calculated
by DS86 and DS02. In light of this situation, theRERF Dosimetry Committee decided to hold aworkshop to discuss these problems and the feasibility of calculating doses for such survivors.
Return to Table of Contents

Opening remarks were given by Dr. Kazunori
Kodama of RERF, and Dr. Stephen D. Egbert of
Science Applications International Corporation(SAIC) provided a key lecture for the workshop.
Dr. Satoru Endo of Hiroshima University and
Dr. Tetsuji Imanaka of the Kyoto University
Reactor Research Center served as discussants.
Presentations were also made by a number of
RERF researchers and staff, including Mr. Tadaaki
Watanabe, Mr. Tomoaki Yamashita, Mr. Takashi
Oda, Mr. Hiroshi Fuchi, and Dr. Harry M. Cullings.
The workshop concluded with detailed discussions and a hands-on demonstration of the models
and tools used at RERF in the 1960s to produce“Globe” (spherical coordinates) data on the shielding of survivors in concrete buildings.
Mr. Watanabe reviewed the categories of survivors with unknown doses, Mr. Oda reviewed
detailed data on concrete buildings, and Mr. Fuchi
reviewed detailed data on air-raid shelters. Of
7,070 survivors in the Life Span Study (LSS) withunknown dose, an estimated 3,729 were in either
concrete buildings (2,114) or air-raid shelters(1,615). There were at the time 24 concrete buildRERF Update Volume 24, Issue 1, 2013

update 14

Conference and Workshop Reports
ings in Hiroshima and 37 in Nagasaki, but manybuildings contained only a few survivors, whereasa few contained many survivors. In regard to feasibility of dose calculation, almost all of the concretebuildings in Hiroshima have floor plans available,
but very few of the survivors in those buildings
have shielding histories that depict their location
within the buildings: 979 of 1,272 survivors inconcrete buildings in Hiroshima were in buildings
with floor plans, but only 218 of those 979 haveshielding histories. In Nagasaki, a larger fractionof survivors have shielding histories but far fewerof the concrete buildings have floor plans: 255 of
842 survivors were in buildings with floor plans,
and 166 of those 255 have shielding histories. In
the case of air-raid shelters, detailed floor plans andarchitectural drawings may not be necessary fordose calculation, but few survivors have shielding
histories depicting their location within the shelter:
1,488 of the 1,615 survivors in air-raid shelters
were in Nagasaki, and only 247 of those 1,488 haveshielding histories. The table indicated below gives
details for individual buildings in terms of the existence of floor plans and the numbers of survivors
with and without shielding histories.
Doses in concrete structures vary greatly
depending on the exact position of survivors within
the structure for which the doses are calculated. Inorder to calculate doses to survivors in a heavyshielding structure, the dosimetry system would
need to calculate “shielded fluences”: numbers ofneutrons and gamma rays in categories of energy

Table. Details of occupants in concrete buildings
Bldg No.

Hiroshima

NagasakiFloor plan*

SH**

No SH

Floor plan

SH

No SH

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
“Others”

1
1
1
1
1
1
1
1
1
0
1
1
1
1
1
0
1
0
0
1
1
1
1
0

3
2
3
7
1
1
25
33
50
2
5
2
13
4
0
0
6
0
2
1
49
1
0
0

0
1
5
10
1
1
21
16
41
5
15
2
147
9
4
2
87
10
33
86
207
97
23
118

0

8

113

0
1
0
1
0
1
1
0
1
1
0
1
0
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
0
1
1
1
1
0
0
0
0
0

38
13
1
10
2
6
2
2
4
2
2
2
2
4
6
1
50
39
7
1
74
19
6
11
4
33
1
26
45
4
7
6
3
1
2
6
11
2

6
1
0
3
0
0
1
1
1
0
1
3
0
2
3
0
7
15
0
0
61
22
4
6
1
15
0
5
20
3
0
1
0
4
20
36
45
100

Total

19

218

1,054

13

455

387

*1 = floor plan available, 0 = no floor plan; **Shielding History (gives location within building)
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RERF Update Volume 24, Issue 1, 2013

Conference and Workshop Reports

update 15

imaginary neutrons or gamma rays through theshielding. Because neutrons can be captured or
scattered in interactions that produce gamma rays,
neutron scattering may give rise to new gamma
rays according to certain probabilities. Monte
Carlo is “an approximate solution to an exact problem”: it can handle a very detailed model of thebuilding, but very few histories end up delivering
dose at the location of interest, and it is difficult
to obtain enough such histories at any location, letalone to map out the dose environment in the entire
building. The discrete-ordinates approach works bypartitioning the building into imaginary cells that
constitute a “spatial mesh” and calculating differential flows of neutrons and gamma rays throughthe mesh. It is “an exact solution to an approximate
problem”: it provides solutions in every location
defined by the center of a cell in the spatial mesh,but it is difficult to make the mesh fine enough toinclude sufficient detail of the building’s structure
and it is also difficult to avoid computational artifacts such as “ray effects.” Dr. Egbert reviewed
software packages of each method and also hybrid
approaches that combine them.
Dr. Cullings reviewed several concerns relating
to the statistical properties of dose estimates thatappear to be possible for survivors in heavy shielding, particularly in concrete buildings, assumingthat the computational problems can be solved,i.e., assuming that sufficient funding is available
for acceptably precise estimates at known locations within a building. Many of the concretebuildings were at distances from the bombs where
the unshielded dose was well above lethal levels,
such that shielded doses inside the buildings could
span a large range from sublethal to supralethallevels. For example, the doses inside the Chinzei
School calculated by Rhoades et al.1 ranged from
0.2 Gy or less at positions deep in the first floor
to well above 30 Gy near the windows on the second floor, and the dose gradients as a function oflocation within the building are correspondingly
steep. As a consequence, the factof survival contains information
about the survivor’s likely position within the building and thecorresponding dose: the morelethal the dose in a given location, the less likely it is that aperson who survived was in thatlocation. For survivors who lackshielding histories to document
their position (location within
the building), it may be difficult
or impossible to obtain a reliably
unbiased estimate of dose—for
example, a simple spatial average
RERF International Workshop: Heavy Structural Shielding held at Hiroshima RERF over a building containing lethal

and direction, at various locations in the structure.
There are two main problems, essentially mattersof practicality, in calculating shielded fluences
within concrete buildings. One problem is thatheavy shielding requires a more difficult calculation: because so few of the neutrons and gamma
rays impinging on the building pass through tocreate dose in the more heavily shielded interior
locations of interest, it may require very large
amounts of computer time, accurate geometries,and sophisticated biasing (putting more effort on
those portions of the incident fluences that lead tothe majority of the shielded fluences in the locations of interest) to do calculations with acceptable accuracy and precision. The other problem
is that, unlike the Japanese houses considered by
the dosimetry systems, each concrete building andeach air-raid shelter is unique, which means it isnecessary to build a detailed computational modeland do a suite of calculations for each building or
shelter. Furthermore, because the shielded fluences
in a heavy structure depend so acutely on the exact
survivor location within the structure, additional
problems, discussed below, arise in calculatingdose estimates for survivors.
Dr. Egbert gave an extensive review of the kindsof computational programs and related softwarethat are available for such calculations. He began
by illustrating the dosimetry method used in thecurrent system and then reviewing two important
papers from 1992 in which doses were calculated
for the occupants of two concrete school buildingsin Nagasaki.1,2 These papers used methods much
like those that would be used in a contemporary
calculation and illustrated a number of importantprinciples that would apply directly to the problems under consideration by RERF.
There are two basic computational approaches
to the shielding calculation: Monte Carlo and discrete ordinates. Monte Carlo works by creating“particle histories” of neutrons and gamma rays,
using rules of probability to propagate individual,

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RERF Update Volume 24, Issue 1, 2013

Conference and Workshop Reports
or supralethal doses in some areas would clearlybe a biased overestimate. Even for survivors withshielding histories, the positional uncertainty may
result in substantial dose uncertainty. In the case of
the doses calculated by Rhoades et al.,1 who had
extremely good position information, the estimatedpositional uncertainty was between 30 and 90 cm
in each of two horizontal directions, and the corresponding dose uncertainty was between about
3% and 56%, although almost all estimates had
uncertainty of less than 30%.
In some sense a concrete building is a microcosm of the entire city, given the range of doses
possible in the building and the dose uncertainty
due to positional uncertainty, and there would be aneed for a method to account for that dose uncertainty as is currently available for other survivors
with “known” doses. There are few if any buildingsthat have enough surviving occupants with shielding histories to allow the dose estimates of thesurvivors in a building to serve as a useful estimateof the frequency distribution of doses among all
possible survivors in that building. Furthermore,such estimates would be clouded by the positional
uncertainty of the survivors with shielding histories, and the need to assume that the survivors withshielding histories would have the same spatial
distribution as the full complement of all survivors
from a building in which the occupants, including
those who did not survive, were evenly distributed
throughout all occupiable parts of the building.
As these are likely to be untenable conditions andassumptions, one would need to consider somethingsuch as a Bayesian approach for the survivors without shielding histories. Both that approach and themethod of accounting for dose uncertainty among
those with shielding histories would have to relyon additional information such as the median lethal
dose estimated by Levin et al.,2 with the attendantconcerns about the accuracy of that estimate and the
caveat that it applies only to survivors without any
concomitant injury from heat or blast trauma.
Mr. Watanabe and Mr. Oda provided a demonstration of the spherical-coordinates projector andrelated tools that were used in the 1960s, with scalemodels of the buildings and shelters, to collect“Globe” data on the shielding in various directions for survivors in heavy shielding. Those data
were used in the tentative dosimetry system T65D
to calculate doses, although they were considered“rough estimates” by Dr. J. S. Cheka of Oak Ridge
National Laboratory in the U.S.,3 who was a leading dosimetry physicist associated with the effort,
and were considered not to be reliably accurate by
Mr. Seymour Jablon.4 The ensuing discussion clarified that, unfortunately, there is no apparent way to
use the Globe data for survivors in concrete buildings, because each such building is unique. ThereReturn to Table of Contents

update 16
fore, we cannot do something analogous to what
was done in DS86 and DS02 in using Globe data
for survivors who were outside but near wooden
houses. To devise a similar method for concretebuildings, we would calculate the doses for various
positions in a model concrete building and then use
the Globe data for those positions and for survivorsin actual concrete buildings to relate the cases of
the actual survivors to positions in the model building. However, we cannot make a model concretebuilding that capably represents all of the various
buildings of interest.
A further general discussion on feasibility ofdose calculation was held. Dr. Egbert pointed outthat calculations would require detailed structural
data for a building, including the thickness of walls
and floor slabs, the dimensions and locations of
windows, the details of any other massive structures such as pillars and beams, and the elemental
compositions of all the related materials. It appears
that work on the heavy shielding problem may continue with performance of calculations for someexample buildings to evaluate feasibility.
I would like to thank the participants of the workshop, especially Dr. Egbert, and Dr. Douglas E.
Peplow of Oak Ridge National Laboratory for granting permission for Dr. Egbert to use his instructional materials on shielding calculation, the members of the RERF Master File Section who prepareddetailed materials and excellent illustrations of theavailable data, and the members of the Departments of Statistics and Epidemiology, as well asothers at RERF who supported the workshop. Dr.
George D. Kerr, an important investigator in thisarea, was unfortunately not able to attend the workshop, but we would like to recognize his contributions to work on this problem over the years, starting with work he did with Globe data and T65D.

References
1. Rhoades WA, Childs RL, Ingersoll DT. Radiation exposure inside reinforced concrete buildings at Nagasaki. Health Phys. 63: 510-21; 1992.
2. Levin SG, Young RW, Stohler RL. Estimationof median human lethal radiation dose computed from data on occupants of reinforced
concrete structures in Nagasaki, Japan. HealthPhys. 63: 522-31; 1992.
3. ABCC Interoffice Memorandum dated 22
September 1970, from Mr. M. Usagawa of theStatistics Department to Mr. Yoshida, re revision of CD#575: code for globe operation for
subjects exposed inside concrete building onclass of estimating dose.
4. Jablon S. ABCC Technical Report No. 23-71:
Atomic bomb radiation dose estimation at
ABCC. Atomic Bomb Casualty Commission,
Hiroshima and Nagasaki, Japan, 1971.
RERF Update Volume 24, Issue 1, 2013

Conference and Workshop Reports

update 17

RERF Hosts International Workshop on Radiation andCardiovascular Disease
Waka Ohishi, Acting Chief
Department of Clinical Studies, Hiroshima
The RERF Department of Clinical Studies,with the help of the Cardiovascular Disease (CVD)
Working Group, hosted a two-day international
workshop titled “Radiation and Cardiovascular
Disease” on February 5 and 6, 2013, in the auditorium of the Hiroshima RERF.
Recent results of the Life Span Study (LSS)
have showed that increased mortality risk fromheart disease and stroke is associated with radiation dose. Looking at the risk by subtype showedno significant association with ischemic heartdisease, cerebral infarction, cerebral hemorrhage,or subarachnoid hemorrhage, whereas significant
associations between radiation dose and hypertensive heart disease, rheumatic heart disease, andheart failure were observed. In addition, increased
risk of myocardial infarction has been observedin the Adult Health Study (AHS), for example,
among female survivors exposed to over 2 Gy atless than 40 years of age. Although no consistent
trend has been observed with regard to stroke,
recent reports indicate that the risk of hemorrhagic
stroke increases with radiation dose in both males
and females.
Based on this background, experts in relevant fields in Japan and abroad, along with RERF
research scientists, made presentations at the workshop to discuss the following questions: What is
consistent or inconsistent in the study results forradiation-associated CVD? What mechanisms areimportant for radiation-associated CVD at highand low-dose exposures? What are the measurable
indicators for evaluation of radiation-associated
CVD? Which statistical methods are useful forevaluating radiation-associated CVD risk?
On the first day of the workshop, Dr. Fred
A. Mettler, Jr. (Clinical and Emeritus Professor,
Department of Radiology, University of New
Mexico) offered a broad-based review of findings
and problems pertaining to radiation risk and cardiovascular disease. He spoke from the viewpointof general concepts and studies of radiation therapy, radiation workers, A-bomb survivors, and animal experiments. Subsequently, Dr. Kotaro Ozasa(Chief, RERF Department of Epidemiology) gave
a lecture titled “Epidemiological Studies of Cardiovascular Disease in the LSS”; Dr. Peter Jacob(Acting Director, Institute of Radiation Protection,
Helmholtz Zentrum München) presented “Radiation Dose Responses of LSS Cardiovascular Disease Mortality”; and Dr. Nobuhiko Ban (Professor,
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Tokyo Healthcare University) offered “Considerations for Dose Response of Radiation-related Cardiovascular Disease.” The session sparked active
discussion about the importance of dose-response
evaluation by subtype and period, and about how
to assess dose response by taking risk factors into
consideration.
During the afternoon session, Dr. Steven E.
Lipshultz (Professor, Leonard M. Miller Schoolof Medicine, University of Miami) delivered alecture titled “Cardiomyopathy Following Radiation Exposure in the Childhood Cancer Survivor
Cohort.” He explained study results (including hisown) based on vast amounts of data from long-term
follow-up of a childhood cancer survivor cohort(considering, for example, heart disease risk by
subtype and the effects on growth hormones by
cranial irradiation). Dr. Ikuno Takahashi (Research
Scientist, RERF Department of Clinical Studies)then presented “Overview of Studies on Cardiovascular Disease in the AHS” and Dr. Fiona Stewart(Associate Professor, Netherlands Cancer Institute)considered “Biological Mechanisms of Radiationinduced Cardiovascular Disease.” Discussion during this session focused on different biologicalmechanisms of radiation-induced cardiovasculardiseases for high-dose exposure as opposed to lowdose exposure, whole body exposure as opposed
to local/cranial exposure, and various cardiovascular disease subtypes. Participants emphasizedthat more appropriate markers (examinations andbiomarkers) need to be selected, taking the aforementioned biological mechanisms into consideration, in order to correctly assess radiation-induced
cardiovascular disease risk.
On the second day, following a lecture by
Dr. Toru Nabika (Professor, Shimane University
School of Medicine) on “Genetic Analysis of
Stroke-prone Spontaneously Hypertensive Rats(SHRSP)—a Genetic Model Rat of Stroke,” Dr.
Norio Takahashi (Consultant, RERF Vice Chairman’s Office) presented “Animal Study for Radiation and Cardiovascular Disease in RERF.” Dr. N.
Takahashi’s study uses SHRSP hypertensive rats
at RERF and is conducted in collaboration with
Dr. Yasuharu Niwa (Associate Senior Scientist,
RERF Department of Radiobiology/Molecular
Epidemiology). A significant finding from thestudy indicated that a correlation was observed
between radiation exposure (1–4 Gy) and cardiovascular disease development based on the SHRSPRERF Update Volume 24, Issue 1, 2013

Conference and Workshop Reports
rat model, with characteristic histopathology in thebrain, heart, and other organs of the irradiated rats.
This result served to focus attention on the importance of research at lower dose ranges.
The concluding session was an overall discussion debating future directions for RERF’s cardiovascular disease studies. The two-day discussions
were summarized by Drs. Kazunori Kodama,
Kotaro Ozasa, Masazumi Akahoshi, and Roy E.
Shore. The speakers, chairpersons, and others are
now preparing a meeting report, which will be submitted to an international journal.
The workshop was held with the support of theInternational Exchange Program Fund from theJapanese Ministry of Health, Labour and Welfare,and organized through cooperation with many of
RERF’s staff members, not only from the Department of Clinical Studies but also from otherresearch departments and the Secretariat. I would

update 18
like to take this opportunity to express my sincere
appreciation for the support and cooperation thatmade this workshop possible.

International Workshop on Radiation and Cardiovascular
Disease held at Hiroshima RERF

Second International Academic Conference on Radiation Health
Risk Management in Fukushima
The second International Academic Conference on Radiation Health Risk Management inFukushima was held in the city of Fukushima overa period of three days, February 25–27, 2013. The
conference was hosted by Fukushima Medical
University, with cooperation from the Fukushima
prefectural government and the Radiation Protection/Risk Management Group, Subcommittee ofClinical Medicine, Science Council of Japan. The
conference objectives were to invite specialists
both inside and outside of Japan to report on topics
related to radiation’s health risks, including information on efforts taking place in Fukushima andresults of related studies conducted throughout theworld, and to foster scientific discussion about such
issues. The conference was attended by about 460
specialists from nine nations, including the USA,
Russia, Germany, and Japan, and from internationalorganizations and universities, including the World
Health Organization (WHO), United Nations Scientific Committee on the Effects of Atomic Radiation(UNSCEAR), International Atomic Energy Agency(IAEA), International Commission on RadiologicalProtection (ICRP), Fukushima Medical University,
Hiroshima University, and Nagasaki University.
On the first day of the conference, four sessions
were held. In Session 1, “Initial Medical Responseto the Fukushima Nuclear Accident,” Dr. Koichi
Tanigawa, Professor at Hiroshima University,
delivered a report on radiation emergency medical issues. In Session 2, “Current Actions of the
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Fukushima Health Management Survey,” representatives of Fukushima Medical University reported
a portion of data analysis results obtained throughfour in-depth examinations/surveys (thyroid
screening, health examinations, survey of pregnant
women and nursing mothers, and survey of mental
care and lifestyles). In Session 3, “Coordination
and Cooperation with Domestic Members (1),” Dr.
Kazunori Kodama, RERF Chief Scientist, madea presentation titled “Support for Fukushima Provided by the Radiation Effects Research Foundation.” In Session 4, “Coordination and Cooperation
with Domestic Members (2),” Dr. Toshiteru Okubo,
RERF Chairman, served as one of the co-chairs.
On the second day of the conference, in Sessions
5–8, presentations were made regarding actions in
response to the earthquake in Fukushima by international organizations, and the experience gained
from the Chernobyl nucler power plant accident
by researchers from abroad, followed by a comprehensive discussion of the conference proceedings.
On the last day, Dr. Shigenobu Nagataki, Professor Emeritus at Nagasaki University (and former
RERF Chairman), delivered a keynote lecture on
the theme “Mission and Responsibility of the Scientific Society in Japan after the Fukushima Accident.” Session 9, “Radiation Health Risk Management,” was followed by the summary discussion
titled “Implications of the Fukushima Accident and
Suggestions for Future Actions,” concluding thethree-day conference.
RERF Update Volume 24, Issue 1, 2013

Conference and Workshop Reports

update 19

Interdisciplinary Education Intensive Course: A Special Training
Program for Recovery from Nuclear Accidents
Ritsu Sakata, Associate Senior Scientist
Department of Epidemiology, Hiroshima
their understanding in fields outside of their areas
A two-day interdisciplinary education intensiveof expertise and also to foster questions and discuscourse, “Radiation biology and medicine overlooksions among participants.
ing the moment of radiation exposure throughout
Despite the unfortunate rain, the course began
the lifetime,” a special human resource training
successfully, with the opening address by Dr.
program for recovery from nuclear accidents, wasToshiteru Okubo, RERF Chairman. On the first
held on March 18 and 19 at the RERF Hiroshima
day in Session 1, “Methods and results of epideLaboratory. This program is supported by the Minmiological studies of atomic bomb survivors,” Dr.
istry of Education, Culture, Sports, Science andKotaro Ozasa, Chief, Department of EpidemiolTechnology and comprises a series of intensive
ogy, lectured on the history of the RERF studies
courses held as part of a larger recovery project iniof A-bomb survivors, including the Life Spantiated in FY2012. It is intended to train specialists
Study (LSS), and their results. Dr. Ritsu Sakata
who have an extensive and deep understanding ofthen provided an explanation of technical terms
the causal relationship between radiation damage
used in Dr. Ozasa’s talk, to facilitate participants’and health effects and can contribute to society.
understanding of the lectures that followed. Dr.
The program covers the following four subcategoHiromi Sugiyama, Acting Chief, Tumor and Tisries in the fields of radiobiology and medicine: 1)
sue Registry Office, Department of Epidemiology,
radiation protection and radiation emergency mediand Dr. Eric Grant, Assistant Chief, Department
cal care, 2) epidemiology and cancer therapy, 3)
of Epidemiology, talked about studies of in utero
individual responses, and 4) molecular responses.
survivors and children of A-bomb survivors,
Six universities, including Kyoto University, as
respectively. Session 2, “Epidemiological researchwell as the Institute for Environmental Sciences
methods enabling such studies,” on the morningand three other research institutes participate in thisof the second day comprised three lectures: “Introprogram, and RERF was responsible for providing
duction to epidemiology” by Dr. Ozasa, “Riskan intensive course on epidemiology in the subcatassessment” by Dr. Sakata, and “Factors that could
egory of epidemiology and cancer therapy. Those
distort the true picture” by Dr. Atsuko Sadakane,
who enroll in the program can choose intensive
Associate Senior Scientist, Department of Epidecourses and international symposiums they wish
miology. The intent of these three lectures was toto participate in from the list of courses and symfamiliarize the participants with epidemiology, theposiums on the program’s webpage. These courses
field that forms the basis for the technical terms
and symposiums are intended mainly for students,
introduced in Session 1. Because these two sesgraduate students, and young researchers.
sions, presented in a day and a half, covered about
Although the courses require no admission
one-third of the contents generally provided in afees, and travel and lodging expenses are paid
six-month course, the participants may not havefrom the program’s fund, in designing the course
fully understood what was being explained. In Sesschedule, we had no idea about the type or number
sion 3, “Interface between animal experiments andof participants who would register, due to the nonepidemiological studies,” on the afternoon of theaccredited nature of the course. In early March,when we learned that there
would be 13 participants
with varied backgrounds,
from university sophomores to first year doctoral
students, with backgrounds
in engineering, science,and medical science, wewavered about the focusof the course. Also, threescientists who had registered as program lecturers
would participate in the
RERF course to deepen
Participants of the interdisciplinary education intensive course held at Hiroshima RERF
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RERF Update Volume 24, Issue 1, 2013

Conference and Workshop Reports
second day, Dr. Nori Nakamura, Consultant, RERF
Department of Genetics, lectured on the challenges
involved in this interface. The topic of biodosimetry was covered by Dr. Satoshi Tashiro, Professor,
Hiroshima University, Dr. Yoshiaki Kodama, Chief,
RERF Department of Genetics, and Dr. Yuko Hirai,
Adjunct Specialist (research scientist), RERF
Department of Genetics, in their lectures on methods based on dicentric chromosomes, chromosometranslocations, and electron spin resonance (ESR),
respectively. The topics in this session were probably the most familiar to the participants, but they
did not ask many questions, perhaps because of themental fatigue from the previous sessions over the
past one-and-a-half days. This somehow worriedus, but we found out later, to our relief, that they
had remained after the lectures, asking questions to
Dr. Nakamura and Dr. Hirai with intense interest.

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update 20
We also realized the difficulty of organizing
such an event. For example, although the Project
Secretariat had asked participants to bring theirlunch, half of them did not, due to the uniquecourse format provided by each of the institutes ofthe program, so they had to go down Hijiyama Hillin the rain for lunch. Also, some participants had
not made hotel reservations prior to their arrival.
Yet, the participants, who voluntarily registered in
the program, were highly motivated to learn anddid their best to understand the lectures despite
their fast pace, even managing to ask questions.
Twelve participants attended the reception heldon the evening of March 18, and actively communicated with each other and the lecturers. I was
impressed by their motivation and sincerely hopethat more students and researchers will specialize
in radiation research.

RERF Update Volume 24, Issue 1, 2013

update 21

Science Articles

Impact of Smoking on Mortality and Life
Expectancy in Japanese Smokers:
A Prospective Cohort Study*
Ritsu Sakata
Department of Epidemiology (Hiroshima), RERF
*This article is based on the following publication:
Sakata R, McGale P, Grant EJ, Ozasa K, Peto R, Darby SC. Impact of smoking on mortality
and life expectancy in Japanese smokers: A prospective cohort study. BMJ 2012; 345:e7093(doi: 10.1136/bmj.e7093)

Introduction
Previous studies have found that smoking
increased the risk of morbidity and mortality frommany diseases in the Japanese as in other populations. However, such studies revealed that themagnitude of risk in Japan was smaller than that inEurope and the U.S., but the reason for that result
is unclear. We examined the impact of smoking on
overall mortality and average life expectancy in theLife Span Study (LSS).
Explanation
1. Methods
Smoking information was obtained by way offour LSS mail surveys (in 1965, 1969, 1978, and1991) and three interview surveys (in 1963, 1965,
and 1968) with the Adult Health Study cohort, an
LSS subcohort. The average length of follow-up
after the first provision by subjects of information
on smoking status was 22.9 years. Age-adjusted
death rates by smoking category and by calendar
year of birth were calculated, resulting in the death
rate ratio of current smokers or former smokers when compared with never smokers. Wheresmoking status that had been previously reportedchanged at a later occasion, such cases were reclassified in accordance with the newly reported smoking status. We also conducted analysis including
radiation dose and lifestyle factors such as alcohol,
confirming that there was no substantial change inthe results.
2. Results of the study
A total of 67,973 subjects (27,311 men and
40,662 women) provided information on smoking
status in at least one of the aforementioned surveys
or interviews.
(1) Risk of smoking by calendar year of birthComparison of death rate by calendar year ofbirth revealed higher death rates for smokers
in all of the birth-year groups than for never
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smokers: death rate ratios of smokers to neversmokers were 1.24 for men born before 1890
and 1.92 for men born in 1930–1945, revealing higher death rate ratios for smokers bornin later decades than for those born earlier. A
similar trend was observed for women.
(2) Impact of age at initiation of smoking
Death rate ratios of smokers were 1.48 and2.21 for men born in 1920–1945 who did notstart smoking until at least the age of 30 andfor men who started smoking before the age of20, respectively. For women, death rate ratios
also increased with decrease in age at initiationof smoking.
(3) Reduction in life expectancy
Among men who smoked at age 35, 78%
survived to the age of 70. In contrast, 78% of
the never-smoker group survived to the age of
75. Similarly, among women who smoked atage 35, 88% survived to age 70, while the same
percentage of never-smoker women survived
to age 74. Consequently, it was found thatsmoking reduced life expectancy by about five
years for both men and women in this group of
smokers. Among men born in 1920–1945 whostarted smoking by 20 years of age and continued smoking, 72% survived to the age of 70
years, while the same percentage of men bornin the same period who never smoked survived
to the age of 78 years. For women, a similar
comparison revealed that 79% of the smokers survived to the age of 70, with the same
percentage of never smokers surviving until
the age of 80. The latter comparison foundthat life expectancy among such smokers was
reduced by eight years and 10 years for men
and women, respectively.
(4) Impact of smoking cessation
Those who stopped smoking by 35 years ofage could avoid almost all of the excess risk
RERF Update Volume 24, Issue 1, 2013

update 22

Science Articles
found in those who continued smoking. Even
those who stopped smoking by the age of 45
could avoid most of the excess risk.
Among those born before 1890, the mean ages atinitiation of smoking were 23 years and 36 years formen and women, respectively; among those bornin 1930–1945, however, the mean ages decreased
to 19.8 years and 24.3 years for men and women,
respectively. Among those born before 1890, theaverage numbers of cigarettes per day were 13 andseven for men and women, respectively; among
those born in 1930–1945, the numbers increased
to 24 and 13 for men and women, respectively. The
present study observed similar levels of reduction

in life expectancy as those observed in studies in
Europe and the U.S. among those born in 1920–
1945 who started smoking before 20 years of age.
The low risk observed in the past among Japanese
may have been affected by the presence of peopleof previous generations whose ages at initiationof smoking were relatively high and numbers ofcigarettes consumed were low. As is the case forEurope and the U.S., it is expected that Japanesepeople who started smoking in the early stagesof adulthood and continued smoking will face areduced life expectancy of about 10 years on average. However, most of such risk can be avoided if
smoking is halted by the age of 35.

Figure. Survival probability from the age of 35 years for Japanese menborn in 1920–1945 (comparison between non-smokers and smokers who started smoking by the age of 20)

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RERF Update Volume 24, Issue 1, 2013

update 23

Science Articles

Unrepairable DNA Double-strand Breaks That Are
Generated by Ionizing Radiation Determine theFate of Normal Human Cells*
Asao Noda
Department of Genetics, RERF
*This article is based on the following publication:
Noda A, Hirai Y, Hamasaki K, Mitani H, Nakamura N, Kodama Y. Unrepairable DNA doublestrand breaks that are generated by ionising radiation determine the fate of normal human cells.
J Cell Sci 2012; 125(22):5280–7 (doi: 10.1242/jcs.101006)

Study Findings
Our study confirmed that unrepairable chromosomal DNA double-strand breaks (DSBs) inducedby radiation exposure were retained in cell nuclei
over the long term as repair protein foci that arelarger than repairable damages, and cells containing these DSBs exhibited a tendency to undergo
premature senescence, with permanently arrested
cell division observed. The numbers of unrepairable DSBs increased with increasing radiation dose
(Figure 1) and built up in the cells with repeatedirradiation, indicating the possibility that measurement of such DSBs could be used to estimate
cumulative radiation dose received previously.

No. unrepairable foci/cell

4.5
4
3.5
3
2.5
2
1.5
1
0.5
0

0

5

10

15

X ray （Ｇｙ）

the genomenote) and might eventually induce tissue
malfunction leading to late radiation effects, we
attempted to detect such damages. By considering
the large repair protein foci retained in cell nuclei
as a ‘mark’ of unrepairable DSBs, we examined
the biological effects of radiation and analyzed themolecular mechanisms underlying such effects.
1. Purpose of study: Considering that unrepairable
genome damages remain in cells and tissues
previously irradiated, we aimed at inventing amethod to detect such damages.
2. Study method: Normal human cells (cultured
in the laboratory) and experimental mice were
irradiated and DSBs remaining in the genome(chromosomal DNA) in cell nuclei over the longterm were detected as large repair protein foci(Figure 2).
3. Results of the study: It has become clear that
unrepairable damages accumulate in cell nuclei
according to radiation dose. In the future, it isnecessary to analyze how such damages could
affect the long-term function of tissues andorgans and how the results of this study tie inwith what has been learned from the studies ofatomic bomb survivors conducted thus far.
note)

The entirety of genetic information contained in DNA

Figure 1. Formation of unrepairable DSBs according toradiation dose

Explanation
Among the long-term effects induced by ionizing radiation in biological organisms, unrepairable
DSBs represent the most significant of the chromosomal DNA damages from radiation exposure. It
was not fully understood, however, how the damages are generated and how they determine the fatesof cells. Based on the idea that unrepairable damages caused by radiation exposure are retained in
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Figure 2. Unrepairable DSB repair protein foci observed incell nucleus one month after irradiation with 6 Gy.
Mostly existing in pairs: at left: 53BP1 antibody
staining; at right: γH2AX antibody staining

RERF Update Volume 24, Issue 1, 2013

update 24

Science Articles

Translocations in Spleen Cells from Adult Mice
Irradiated as Fetuses Are Infrequent,
but Often Clonalnote) in Nature*
Yoshiaki Kodama
Department of Genetics, RERF
*This article is based on the following publication:
Nakano M, Kodama Y, Ohtaki K, Nakamura N. Translocations in spleen cells from adult mice
irradiated as fetuses are infrequent, but often clonal in nature. Radiat Res 2012; 178(6):600–3(doi: 10.1667/RR3074.1)

Study Findings
We previously reported on the basis of studiesof A-bomb survivors and mice that adults irradiatedas fetuses do not record chromosome aberrations(translocations) in blood cells unlike irradiatedadults. In the mouse studies, using a two-color
fluorescent in situ hybridization (FISH) method
to detect some of the translocations, the translocation frequencies occurring in all chromosomes
were calculated. However, there is the possibility
that such studies resulted in underestimated values. To overcome this problem, multi-color FISH
(mFISH), a method that can detect translocations
occurring in all chromosomes, was employedin this study. This re-examination showed thattranslocation frequency previously estimated on
the basis of the two-color FISH method correctly
represented the aberration frequency in all chromosomes. It also was indicated that among adult mice
irradiated as fetuses or neonates, radiation damage
was recorded in an extremely small population ofhematopoietic stem cells as chromosome aberrations, and their progenitors proliferated as clonalcells bearing those chromosome aberrations.
Explanation
Irradiated mouse fetuses or neonates showedvery few translocations when the mice were subsequently examined at 20 weeks of age. Reasons
include that the two-color FISH method, which candetect only some translocations, may not have beenable to correctly detect all chromosome aberrations
including those of a clonal nature. For this reason,
Dr. Mimako Nakano, Department of Genetics,
RERF, and others used mFISH technology, which
can detect translocations in all chromosomes, toverify the previous outcomes.
1. Purpose
The result by the two-color FISH method
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showed potential bias due to the method’s technical limitations (it can only detect some translocations). To look into these problems and to detect
all translocations, mFISH was used for analysis in
this study.
2. Methods
B6C3F1 fetal mice at 15.5 days (maternal age:
12 weeks old) and three- to four-day-old neonates
were exposed to 2 Gy of X rays. When the offspring or neonates reached 18–21 weeks of age,chromosome specimens were prepared from theirspleen T lymphocytes. For four and three mice irradiated as fetuses and neonates, respectively, as wellas one exposed mother of an irradiated fetus, themFISH analysis was conducted (Figure).

Figure. Translocation of chromosomes 1 and 12 detected by
mFISH: t(1q–;12q+). Aberrant chromosomes (arrow)are of different colors, indicating a transfer took place
between chromosomes 1 and 12 (translocation).

3. Results of the study
The present mFISH analysis of the same miceof the previous studies confirmed that translocation frequency in spleen cells was nearly zero,
the same as was indicated in the previous studies
when mice were irradiated as fetuses or neonates
RERF Update Volume 24, Issue 1, 2013

update 25

Science Articles
and analyzed for translocations. Furthermore,translocations that were previously suggested to beclonal were indeed confirmed to be clones in thepresent analysis. New clonal chromosome aberrations previously not detected were also identified.
At the same time, a number of translocations weredetected in the mother exposed to X rays, consistent with the result from the previous studies, but
no clonal chromosome aberrations were detected.
The above results suggest that while a majority ofhematopoietic stem cells in fetuses and neonates do
not record radiation effects, a very small proportion
not only record radiation-induced chromosome
aberrations in the same way as hematopoietic lymphocytes of adults but also proliferate as a small
number of surviving stem cells (detected as clonal
chromosome aberrations). Since the previous studies indicated no record of chromosome aberrations
in lymphocytes when fetuses were exposed to radi-

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ation, we began to wonder about the results of studies conducted in England and other countries in the
1950s indicating that childhood leukemia increased
with fetal exposure to diagnostic X rays (exposure
to about 10 mGy). The present study showed thatradiation effects were recorded in some of the fetal
hematopoietic stem cells and furthermore that suchcells clonally proliferated. Thus we now have someevidence in an animal model that chromosomal
alterations induced by radiation in utero may bepersistent enough to cause childhood leukemia.
note)

In chromosome studies, identical chromosome aberrations are sometimes detected in multiple cells. It isconsidered that a single stem cell with chromosome
aberrations proliferated within the organism to giverise to such cells, resulting in what are called clonal
chromosome aberrations.

RERF Update Volume 24, Issue 1, 2013

update 26

Science Articles

Association between Chronic Kidney Disease andCardiovascular Disease Risk Factors
in Atomic Bomb Survivors*
Nobuko Sera
Department of Clinical Studies (Nagasaki), RERF
*This article is based on the following publication:
Sera N, Hida A, Imaizumi M, Nakashima E, Akahoshi M. The association between chronic
kidney disease and cardiovascular disease risk factors in atomic bomb survivors. Radiat
Res 2013; 179(1):46‒52 (doi: 10.1667/RR2863.1)

Study Findings
We observed among the A-bomb survivors associations between chronic kidney disease (CKD)
and the cardiovascular disease (CVD) risk factorsof hypertension, diabetes mellitus (DM), hyperlipidemia, and metabolic syndrome (MetS). We
also observed an association between CKD andradiation dose. The most severe category of CKD(severe renal dysfunction) in particular was significantly associated with radiation dose.
Explanation
Still much debated is whether the mechanismof CVD development is the same for high-dose
exposure from cancer radiotherapy (50–60 Gy)
and exposure in the A-bomb survivors (1–4 Gy).
However, associations between A-bomb radiationdose and metabolic CVD risk factors including
hypertension, abnormal lipid profiles, fatty liver,and high inflammatory marker values have been
observed, suggesting the involvement of such factors in the increased CVD rates observed among
the A-bomb survivors.
In recent years, CKD has become known as arisk factor for CVD. CKD is a new disease concept first advocated by the U.S. National Kidney
Foundation in 2002. An association between renal
failure mortality and radiation dose was recently
reported in terms of kidney disease in the A-bomb
survivors. Until now, however, there were noreports and little was known about the association
between A-bomb radiation and CKD.
This study investigated among the Adult HealthStudy (AHS) participants in Nagasaki the associations between CKD and hypertension, DM, hyperlipidemia, and MetS, and between dose in air at thesurvivor’s shielded location and CKD as well as
renal dysfunction.

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1. Purpose of the study
To examine the associations between CKD and
the CVD risk factors of hypertension, DM, hyperlipidemia, and MetS, and the association between
radiation dose and CKD.
2. Materials and methods
We classified renal dysfunction in 1,040 AHS
participants in Nagasaki, who were examined in
2004–2007, as normal (121 persons; estimatedglomerular filtration rate [eGFR] ≥90 ml/min/1.73m2); mild (686 persons; eGFR 60–89 ml/min/1.73m2); moderate (217 persons; eGFR 30–59 ml/
min/1.73 m2); or severe (16 persons; eGFR <30 ml/
min/1.73 m2). We diagnosed subjects in the moderate and severe renal dysfunction groups as having
CKD (233 persons; eGFR ≤59 ml/min/1.73 m2)
based on accepted diagnostic standards.
After adjusting for age, gender, and smoking
and drinking habits, we investigated the associations between CKD and hypertension, DM, hyperlipidemia, and MetS. Among the 1,040 participants, we analyzed the associations between CKD/
renal dysfunction and radiation dose for 746 whoseA-bomb radiation doses were known.
3. Results of the study(1) Association between CKD and CVD risk factors
CKD was found to be associated with
the CVD risk factors of hypertension (oddsratio [OR] 1.57, 95% confidence interval [CI]1.12–2.20, P = 0.009), DM (OR 1.79, 95% CI
1.23–2.61, P = 0.002), hyperlipidemia (OR1.55, 95% CI 1.12–2.14, P = 0.008), and MetS
(OR 1.867, 95% CI 1.32–2.63, P < 0.001), withmild renal dysfunction in particular associatedwith hyperlipidemia and MetS (Table 1).
(2) Association between CKD and radiation dose
CKD was associated with radiation dose
(OR/Gy 1.29, 95% CI 1.01–1.63, P = 0.038),
and severe renal dysfunction was significantly
RERF Update Volume 24, Issue 1, 2013

update 27

Science Articles
associated with radiation dose (OR/Gy 3.19,
95% CI 1.63–6.25, P < 0.001) (Table 2).
Our study was the first to indicate associations
between radiation dose and CKD or severe renal
dysfunction in the A-bomb survivors. Moreover,the study revealed that CKD was associated with
the CVD risk factors of hypertension, DM, hyperlipidemia, and MetS.
The aforementioned findings suggest the pos-sibility that CKD is associated with the increased
CVD rates observed among the A-bomb survivors.
Care should be taken when interpreting the results,
however, since the study subjects were AHS participants in Nagasaki, and as a result, the numberof those with severe renal dysfunction, 16 persons, was small. For that reason, we are planninga larger future study involving both Nagasaki andHiroshima AHS participants.

Table 1. Odds ratio (95% confidence interval [CI]) of
cardiovascular disease (CVD) risk factors forchronic kidney disease
CVD risk factor

Odds ratio (95% CI)

PHypertension
Diabetes mellitus
Hyperlipidemia

1.57 (1.12–2.20)
1.79 (1.23–2.61)
1.55 (1.12–2.14)

0.009
0.002
0.008

Metabolic syndrome

1.86 (1.32–2.63)<0.001

P: Compared with combined normal and mild renal
dysfunction groups (n = 807). CKD (moderate-severe)groups (n = 233) were adjusted for age, gender, andsmoking and drinking habits.

Table 2. Odds ratio (95% confidence interval [CI]) of radiation dose for chronic kidneydisease (CKD)
Renal dysfunctionnNormal-mild
584
Moderate
149
Severe13
CKD (moderate+severe) 162

Not adjusted OR/Gy(95% CI)1
1.13 (0.90–1.44)
2.25 (1.36–3.78)
1.26 (1.01–1.57)

P

0.295
0.002
0.040*

Adjusted OR/Gy(95% CI)1
1.15 (0.89–1.48)
3.19 (1.63–6.25)
1.29 (1.01–1.63)

P

0.293
<0.0010.038**Compared with combined normal and mild renal dysfunction groups (n = 584). Adjusted
for age, gender, and smoking and drinking habits, hypertension, diabetes mellitus, hyperlipidemia, and metabolic syndrome. Radiation dose for CKD analyzed with ordinal logistic
regression model.

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RERF Update Volume 24, Issue 1, 2013

Human Interest Notes

update 28

A Farewell Note with Reflections on the Last Five Years
Evan B. Douple
Former Associate Chief of Research
It has been about six months since I retired fromRERF and, as I reflect back on my five years inJapan, I feel very fortunate to have had the professional opportunity to work at RERF and to live in
Hiroshima. That experience was far more enriching, meaningful, and enlightening to me than I had
ever imagined. It also helped to bring a form ofclosure to my career in radiation science.
In graduate school at Kansas University theprofessors included early findings of ABCC in theirlectures, my post-doctoral mentor at the Universityof Wisconsin—Dr. Kelly Clifton—became a director at RERF, and while serving as a professor in theDartmouth Medical School I would use the findings published in RERF papers in my lectures. I
would learn that over the years several Dartmouthaffiliated scientists supported RERF including suchinfluential scientists as Dr. James Neel, Dr. Gilbert
Beebe, Dr. James Crow, and Dr. Stuart Finch. It
was very gratifying, therefore, that after supporting
RERF through my responsibilities at the National
Academies, I would have the opportunity to contribute to RERF as Associate Chief of Research.
It was an exciting and interesting time to be at
RERF with some unique opportunities to try tohelp RERF face several interesting challenges. For
example, RERF transitioned to a public interest
incorporated foundation, explored how to improve
its public relations activities and more effectively
and proactively communicate its findings andenhance global visibility, as well as increased its
educational activities including the inauguration of aseries of public lectures. RERF scientists developed
guidelines for the use of its precious biosamples andestablishment of the Biosample Center. They alsobegan developing a long-range future plan for RERF
and sought advice and assistance in examining thefuture role of RERF’s basic science departments
in meeting RERF’s research goals. Workshops
were held that explored the potential for RERF
collaborative studies to incorporate state-of-the-art
technologies to examine a role for: (a) epigenetics
as a mechanism for radiation-induced effects; (b)stem cells as targets for damage that ultimately
leads to health effects; and (c) genomic sequencing
to resolve the issue of radiation risk for heritableeffects in humans. It was exciting to be involved in alarge external five-year grant from the U.S. National
Institute of Allergy and Infectious Diseases thatenabled RERF scientists to explore the role of radiReturn to Table of Contents

ation-induced immunosenescence in collaboration
with approximately 26 scientists from laboratories
in Japan and the U.S. And while it was professionally an especially interesting time to be living
in Japan when the Fukushima accident occurred,
the event posed a large number of challenges for
RERF scientists to communicate RERF’s results ina relevant manner to the exposed populations, thegeneral public, and local and national governments.
I already miss many things about RERF,
Hiroshima, and Japan, including the natural beauty,
culture, and people. In reflecting back on the last five
years, I am even more grateful for the many RERF
nakama (colleagues and friends) who helped support
me and made my experience at RERF so special.
My fondest memories are of the “team” effort, thehard work of many loyal employees, and the spiritof dedication of the RERF leadership, scientists,and support staff. I will never forget the words ofappreciation expressed by Mr. Hisashi Onishi as therepresentative of the Long Service Award recipientsat the first RERF Long Service Award ceremony that
I attended in 2008: “It would be self-indulgent of us
to sentimentally dwell on RERF’s past achievements
and memories, for RERF faces many challenges toovercome in the future”; and “We pay our sincere
respects to the major achievements reached by ourmany predecessors and to their dedicated work, andat the same time, we will continue to do our utmost
to secure RERF’s future. . .” I too hope to continue tohelp support RERF, and since I hope our paths willcontinue to cross, somehow “farewell” sounds better
than “goodbye.”Ganbatte kudasai!

Dr. Evan B. Douple in his office at RERF

RERF Update Volume 24, Issue 1, 2013

update 29

Human Interest Notes

Reflections on My Retirement
Kazue Imai, Former Associate Senior Scientist
Department of Radiobiology/Molecular Epidemiology
I have special feelings about Hiroshima. I waslives before the atomic bombing. Before I cameborn on August 6, 1952, in Tokyo. By a curious
to live in Hiroshima, I learned about the city
coincidence, this is also the anniversary of theindirectly, through written documents and video
atomic bombing of Hiroshima. Perhaps because ofimages. But actually living in Hiroshima enabled
this, my mother developed a strong interest in theme to understand more closely the grief of A-bombatomic bombings. She read books on the bombings
survivors who lost their family members, friends,
and in 1968 took my younger brother and me toand other close associates through the atomic
the first A-bomb exhibition, which was held in thebombing, and who still suffer from radiation effects
Matsuzakaya Department Store in Ginza, Tokyo.
and fear them. I believe that this is the most signifiI was shocked by the exhibition and horrified bycant experience I gained by working for RERF.
the cruelty of the atomic bombings. Despite my
In terms of my life as a researcher, I moved
mother’s intention, this experience had the effectfrom the Saitama Prefectural Cancer Center toof making me keep my distance from Hiroshima
RERF together with Dr. Hidetaka Eguchi in Julyand Nagasaki. So when I received an offer to moveof 2001. We were recruited by RERF when Dr. Kei
from the Saitama Prefectural Cancer Center to the
Nakachi, also from the Saitama Center, assumed
Radiation Effects Research Foundation (RERF) in
the position of Chief of RERF’s Department ofHiroshima, I was hesitant about it, even though I
Epidemiology. I was assigned to the Department of
was already in my late forties. However, I considEpidemiology in my first year with RERF. Because
ered the offer to be an opportunity, and I found theI was poor in English, I was very nervous, as there
courage to move to Hiroshima.
were a number of foreign research scientists workIf you walk around Hiroshima, you will see
ing at the Departments of Epidemiology and Statiscenotaphs and memorial monuments for A-bomb
tics. Contrary to my apprehensions, however, I was
victims everywhere in the city. In temples, you see
warmly welcomed and encountered no problems
that almost every sotoba (a tall, narrow wooden
whatsoever.
tablet set up behind a grave for the repose of
In the second year, I was transferred to thethe dead) is inscribed with the date August 6,
Department of Radiobiology/Molecular Epide1945. People I have become acquainted with inmiology (RME) together with Drs. Nakachi andHiroshima, including taxi drivers, with almost
Eguchi. The Immunology Laboratory was studying
no exception, had an A-bomb survivor in theirimmune-related biomarkers in relation to radiation
family or among their relatives. Every year with
exposure, using blood samples donated by A-bomb
the approach of August 6, the anniversary of thesurvivors to elucidate the mechanisms that made
Hiroshima atomic bombing, many people comeit possible for health effects from radiation to perto Hiroshima from other parts of Japan, as well assist for more than 60 years. When I was with thefrom abroad, during the heat of the Hiroshima sumSaitama Prefectural Cancer Center, I was engaged
mer. While the city center is packed
with visitors, in the part of Hiroshima
where I lived, I could hear my neighbors chanting Buddhist sutras, granting a feeling of somber tension to theatmosphere.
Because Hiroshima is located along
the Seto Inland Sea, the city is blessedwith a temperate climate and natural
beauty. Tasty fish and fruit are readily available. Hence, Hiroshima is avery easy city to live in, with a touchof urban style. While I was living in
Hiroshima, breathing the air, I could
imagine how actively people in thiscity must have gone about their own
Dr. Kazue Imai (center) in meeting with her colleagues
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RERF Update Volume 24, Issue 1, 2013

Facts and Figuresin a study of individual variation in carcinogenic risk. We considered lifestyles and measured
metabolism- and immune-related biomarkers andgene polymorphisms, using molecular epidemiological methods based on biological samples (suchas blood) to study their associations with cancer
development. For this reason, I had no trouble
adapting to the research focus at RERF’s RME. I
believe that I was able to contribute to immunogenome and immunosenescence research projects, for

update 30
example, in cohort selection and preliminary analysis, through my experience in the area of molecularepidemiology of cancer.
I consider myself very lucky to have had theopportunity to participate in the RME studies. I
was able to conduct useful research right up to the
day of my retirement. I owe this accomplishment to
my colleagues at RME as well as my other RERF
coworkers. In conclusion, I would like to express
my sincere appreciation to everyone at RERF.

LSS Survivors with Unknown Doses
Harry M. Cullings, Chief
Department of Statistics
Among the members of the Life Span Study(LSS), 7,070 of 93,741 survivors who were in
Hiroshima or Nagasaki at the times of the bombings, or 7.5%, do not have doses calculated by
the 2002 dosimetry system DS02—we commonlyrefer to such individuals as having “unknown
doses.” All of these survivors have known distances
and therefore the unshielded doses in air at theirdistances are known—it is their shielding that is
unknown. A survivor’s dose can almost always be
estimated with an estimate of average shieldingor similar method. In fact, some large groups ofsurvivors who lack detailed shielding data, such as
those who were inside Japanese wooden houses,
have dose estimates that are calculated by using
population-average shielding factors derived fromsurvivors who do have the detailed shielding data.
However, the quality of the estimate that can beobtained by such methods depends on the type ofshielding and the available data, and even the best
feasible estimate may not be acceptable for use in
RERF studies. There are various reasons why an
acceptable estimate of an average shielding factor
might not be available. If the dosimetry systemcannot calculate doses for a given type of structure,
an accurate estimate of the shielding for survivors
in a structure of that type cannot be made, even if
detailed information about the structure is available. On the other hand, for a group of survivors
who lack detailed shielding data, it may be thatgenerically acceptable estimates of shielding factors are available from the dosimetry system forthe shielding categories of at least some of thesurvivors in the group, but a statistically unbiased
average shielding factor for the group cannot be
reliably constructed.
The decisions whether or not to calculate doses
Return to Table of Contents

in particular situations have always been made ina systematic way as part of the implementation ofeach new dosimetry system. They have changed
somewhat with the systems: most notably, theimplementation of dosimetry system DS86, established in 1986, involved more rigorous criteria thanwere used for T65D, the tentative dosimetry system
initiated in 1965. Whereas the implementation of
T65D used ad hoc estimates of shielding in somecases, DS86 relied exclusively on shielding that
could be calculated systematically using its models of buildings, terrain, and other factors, alongwith its Monte Carlo methods, and the most recent
dosimetry system DS02 continued in the samevein.
Here, then, is a breakdown of the classificationof survivors with unknown doses in the current
implementation of DS02:• A total of 3,729 of the survivors with unknown
doses were in concrete buildings or underground air-raid shelters. Some of the physicaland statistical issues affecting the decision not
to calculate those doses are discussed in areport of an RERF workshop on heavy structural shielding in this issue of Update (seepage 13).
• A related category of unknown doses, comprising 2,515 survivors, is for those withwell-described but complex or unusual shielding that was not practical to model for calculation by DS86 or DS02. This category
includes survivors who were inside of astreetcar, on a boat, behind a large tree, and soon.
• Another category, 415 survivors, includes
those who were outside but lack detailed dataon their shielding by nearby structures, if
RERF Update Volume 24, Issue 1, 2013

RERF’s Views on Residual Radiation
any—such survivors do not receive dose estimates if they were at distances less than 2,000
m. This category also includes survivors who
indicated they had been “in the open,” i.e., notnear any building or terrain that would haveprovided shielding, but who did not have any
thermal injury to exposed skin (“flash burns”),
as a lack of this type of injury was considered
to be implausible at distances <2 km if theperson had been completely in the open. (Atgreater distances, overall population-average
shielding factors, based on information fromsurvivors with detailed shielding data who
were outside buildings or in the open, areused.)• Another 205 survivors with unknown doses
were located in factory buildings that could
not be modeled by DS86 and DS02 due tolimited resources affecting the number ofbuilding models that could be made orunavailability of the details of building construction.
• Finally, there were 206 survivors with noshielding information whatsoever, and these

update 31
survivors do not receive calculated doses ifthey were at distances where the unshielded
dose in air exceeds 10 mGy. (At greater distances, overall population-average shielding
factors, including detailed shielding data forboth those who were inside and those who
were outside buildings, are used.)
These implementation decisions are subject toreview by the RERF Dosimetry Committee andcould change in the future with advances in thephysics and statistics of the dosimetry. Additional
details appear in the reports of dosimetry systems
DS86 and DS02, which are available on the RERF
website (www.rerf.jp), in Cullings et al., Radiation Research 166(1): 219–54, 2006, and in Ozasa
et al., American Journal of Epidemiology 177(6):569–73, 2013. The author would particularly liketo acknowledge the extensive work that was doneat RERF by Dr. George D. Kerr and Dr. Dale L.
Preston, along with many others such as Dr. Shoichiro Fujita and Ms. Sachiyo Funamoto, in theimplementations of DS86 and DS02.

RERF’s Views on Residual Radiation
The article titled “RERF’s Views on Residual
Radiation” was posted on the RERF website on
December 8, 2012.
Based on the results of analyses of radiation
doses from the atomic bombings that have been
conducted by the Radiation Effects Research
Foundation (RERF) and many other researchers
in this field, RERF has consistently explained thatthe involvement of residual radiation is not as significant as the effects from initial radiation (direct
radiation). Nevertheless, criticism and doubts continue to arise that RERF has not given due consideration to data on residual radiation. The relevant
website article maintains that such criticism anddoubts are based on misunderstandings and aims toprovide the public with accurate information about
the issue of residual radiation.
Since the media’s first coverage of the YamadaJones Report (Oak Ridge National Laboratory
Report, ORNL-TM-4017, 1972) in 2011, theReturn to Table of Contents“black rain” issue has again attracted the public’s attention. As a result, the matter has been
picked up by numerous media outlets, leading tosome reports that are not entirely accurate. As an
extreme example, one television program impliedthat RERF’s risk data were useless because theradiation doses used in our radiation risk analysis
work did not include doses from residual radiation. We are concerned that, if the present situation
continues, RERF’s research results, which provide
the scientific basis for radiation risk assessment
and radiation protection standards throughout theworld, may be grossly misunderstood, leading to
unnecessary worries among the public, including
A-bomb survivors. We are therefore informing ourreaders in this latest Update about the website article (http://www.rerf.jp/news/pdf/residualrad_ps_e.
pdf) in the hopes of explaining RERF’s views andproviding information on this important issue.

RERF Update Volume 24, Issue 1, 2013

update 32

Research Protocol and Recent Publications

Research Protocol Approved in
May 2012–April 2013

Recent Publications

RP 2-12 A Study of Circulatory Diseases
Using Animal Models Irradiated with Lower
Doses (Addendum to RP 1-11)
Takahashi N, Niwa Y, Murakami H, Ohishi W,
Misumi M, Hsu WL, Hayashi T, Kokubo T, Inaba T,
Nagamachi A, Oghiso Y, Tanaka S, Kusunoki Y
The Life Span Study (LSS) data indicate that
there are radiation-associated risks for hypertensive heart disease and stroke, and the Adult HealthStudy (AHS) data suggest there are radiation-associated risks for hypertension. We hypothesize thatradiation may result in a higher risk for circulatory
diseases (CD), and we started a study using strokeprone spontaneous hypertensive rats (SHRSP) as a
CD animal model. In the study of RP 1-11, radiation doses from a brief single exposure were given
to the rats (1, 2, and 4 Gy, with non-exposed [0 Gy]
rats used as controls). The results suggested that thelife span of irradiated rats decreased with statisticalsignificance compared to the control rats. We also
evaluated radiation effects for morphological andpathological phenotypes in collaboration with theInstitute for Environmental Sciences. The results
showed that the phenotypic changes observed in
the organs (brain, heart, and kidney) of irradiatedrats were more severe than those observed in theorgans of control rats. Thus, our results suggest thata separate study in which rats are irradiated withless than 1 Gy may be an opportunity for providing us with additional interesting data. The purposeof this addendum RP using SHRSP rats is that wewill evaluate radiation effects on CD focusing onlower-dose radiation exposure (<1 Gy) in rats byexamining morphological and pathological phenotypes and measuring the same blood biomarkers as
used in the original RP. In addition to the above, weplan to examine the effects of lower-dose radiation
exposure on the life span of SHRSP rats.
The second purpose of this addendum is to evaluate acceleration of the development of hypertension in spontaneous hypertensive rats (SHR) afterradiation exposure (0 Gy to 4 Gy). In the previous
study using SHRSP rats, we could not measure
blood pressure after SHRSP rats showed the first
stroke symptoms, since we were concerned thatthe measurement of blood pressure might cause
the next stroke symptoms in the rats. We will also
conduct the same examinations in the SHR rats asin the SHRSP study. The SHR rat study will beable to provide more information on the association between radiation exposure and developmentof CD.

Asakawa J, Kodaira M, Cullings HM, Katayama H,
Nakamura N: The genetic risk in mice fromradiation: An estimate of the mutation induction
rate per genome. Radiat Res 2013 (March);
179(3):293-303. (RERF Report 9-12)

Return to Table of Contents(Japanese): the original article is in Japanese.

Asia Pacific Cohort Studies Collaboration (RERF:
Nakachi K): Diabetes, body mass index and theexcess risk of coronary heart disease, ischemic
and hemorrhagic stroke in the Asia Pacific
Cohort Studies Collaboration. Prevent Med 2012
(January); 54(1):38-41.
Boffetta P, Hazelton WD, Chen Y, Sinha R, Inoue
M, Gao YT, Koh WP, Shu XO, Grant EJ, Tsuji I,
Nishino Y, You SL, Yoo KY, Yuan JM, Kim J,
Tsugane S, Yang G, Wang R, Xiang YB, Ozasa
K, Nagai M, Kakizaki M, Chen CJ, Park SK,
Shin A, Ahsan H, Qu CX, Lee JE, Thornquist M,
Rolland B, Feng Z, Zheng W, Potter JD: Body
mass, tobacco smoking, alcohol drinking andrisk of cancer of the small intestine—a pooled
analysis of over 500,000 subjects in the Asia
Cohort Consortium. Ann Oncol 2011 (December); 23:1894-8. doi: 10.1093/annonc/mdr562[Epub]
Hamasaki K: Radiation effects on the human body.
Sangyo Hoken 21 [Occup Health 21] 2013 (January); 18(3):5-7. (Japanese)
Hamatani K, Mukai M, Takahashi K, Hayashi Y,
Nakachi K, Kusunoki Y: Rearranged anaplastic
lymphoma kinase (ALK) gene in adult-onset papillary thyroid cancer amongst atomic bomb survivors. Thyroid 2012 (November); 22(11):11539. (RERF Report 15-11)
Hayashi T, Morishita Y, Khattree R, Misumi M,
Sasaki K, Hayashi I, Yoshida K, Kajimura J,
Kyoizumi S, Imai K, Kusunoki Y, Nakachi K:
Evaluation of systemic markers of inflammation
in atomic-bomb survivors with special reference
to radiation and age effects. FASEB J 2012
(November); 26(11):4765-73. (RERF Report
10-12)
Hsu WL, Preston DL, Soda M, Sugiyama H,
Funamoto S, Kodama K, Kimura A, Kamada N,
Dohy H, Tomonaga M, Iwanaga M, Miyazaki Y,
Cullings HM, Suyama A, Ozasa K, Shore RE,
Mabuchi K: The incidence of leukemia, lymphoma and multiple myeloma among atomic
bomb survivors: 1950-2001. Radiat Res 2013
RERF Update Volume 24, Issue 1, 2013

Recent Publications(March); 179(3):361-82.
Imaizumi M: Radiation and thyroid diseases—
Knowledge of atomic-bomb survivors. Saishin
Igaku [Mod Med] Extra Issue 2012 (October);
235-41. (Japanese)
Imaizumi M: Radiation effects on the thyroid:
What has been learned from the atomic bombradiation and Chernobyl accident. Proceedingsof the FY2011 Radiation Epidemiology Research
Meeting. Tokyo: Radiation Effects Association;
2012, pp 6-8. (Japanese)
Imaizumi M, Yamashita S: Radiation exposure andthyroid function disorder. Curr Ther 2013
(January); 31(1):92. (Japanese)
Kodama K: Epidemiological studies on cardiovascular disease in Hiroshima and Nagasaki, NIHON-SAN Study, and training of young cardiovascular epidemiologists by conducting teaching
seminar. Nihon Junkankibyo Yobogakkaishi [Jpn
J Cardiovasc Dis Prev] 2013 (January); 48(1):4250. (Japanese)
Kodama K: Radiation health effects: radiation andcancer risk in atomic bomb survivors. Medical
Science Digest 2012 (November); 38(13):20-3.
(Japanese)
Kondo H, Soda M, Mine M, Yokota K: Comparison
by bombing status and changes of cancer incidence among the A-bomb survivors in Nagasaki
City (1970-2007). Nagasaki Igakkai Zasshi[Nagasaki Med J] 2012 (September); 87(Special
issue):191-4. (Proceedings of the 53rd Late
A-bomb Effects Research Meeting, 2012) (Japanese)
Kusunoki Y, Yoshida K, Kubo Y, Yamaoka M,
Kajimura J, Hayashi T, Nakashima E, Ohishi W,
Fujiwara S, Hakoda M, Akahoshi M: Effects ofatomic-bomb radiation on human immune
responses. Report 26: Dose-dependent increases
in percentages of both Th1 and Th2 cells in the
peripheral blood lymphocyte population.
Nagasaki Igakkai Zasshi [Nagasaki Med J] 2012
(September); 87(Special issue):265-8. (Proceedings of the 53rd Late A-bomb Effects Research
Meeting, 2012) (Japanese)
Lin Y, Fu R, Grant E, Chen Y, Lee JE, Gupta PC,
Ramadas K, Inoue M, Tsugane S, Gao YT,
Tamakoshi A, Shu XO, Ozasa K, Tsuji I,
Kakizaki M, Tanaka H, Chen CJ, Yoo KY, Ahn
YO, Ahsan H, Pednekar MS, Sauvaget C,
Sasazuki S, Yang G, Xiang YB, Ohishi W,
Return to Table of Contents

update 33
Watanabe T, Nishino Y, Matsuo K, You SL, ParkSK, Kim DH, Parvez F, Rolland B, McLerran D,
Sinha R, Boffetta P, Zheng W, Thornquist M,
Feng Z, Kang D, Potter JD: Association of bodymass index and risk of death from pancreas cancer in Asians: findings from the Asia Cohort
Consortium. Eur J Cancer Prevent 2012 (October
10):1-7. doi: 10.1097/CEJ.0b013e3283592cef[Epub ahead of print]
Nakamura N: How to tell the public about issues
that are under debate. Kankyo to Kenko [Environ
Health] 2013 (March); 26(1):38-42. (Japanese)
Nakamura N, Nakano M, Hamasaki K, Ohtaki K,
Sakata R, Sugiyama H, Noda A, Kodama Y: Is ittrue that radiation-associated risks are higher following irradiation of fetuses as compared withchildren? Hoshasen Seibutsu Kenkyu [Radiat
Biol Res Commun] 2012 (September);47(3):272-86. (Japanese)
Nakano M, Kodama Y, Ohtaki K, Nakamura N:
Translocations in spleen cells from adult mice
irradiated as fetuses are infrequent, but oftenclonal in nature. Radiat Res 2012 (December);178(6):600-3. (RERF Report 7-12)
Noda A, Hirai Y, Hamasaki K, Mitani H, Nakamura
N, Kodama Y: Unrepairable DNA double-strand
breaks that are generated by ionising radiation
determine the fate of normal human cells. J Cell
Sci 2012 (November); 125(22):5280-7. (RERF
Report 10-11)
Ozasa K: Association between radiation exposureand non-cancer disease death in the atomicbomb survivors. Hoshasen Bogo Bunkakaishi[Jpn Soc Radiol Technol] 2012 (October); No.
35:27-30. (Japanese)
Ozasa K: Health effects of atomic-bomb radiation. Nippon Eiseigaku Zasshi [Jpn J Hyg] 2013
(March); 68(Supplement):S78-9. (Abstracts of
the 83rd Annual Meeting of the Japan Societyfor Hygiene, Kanazawa, 24-26 March 2013)(Japanese)
Ozasa K: Late health effects of radiation among
the atomic-bomb survivors. Nagasaki Igakkai
Zasshi [Nagasaki Med J] 2012 (September);87(Special issue):157-60. (Proceedings of the
53rd Late A-bomb Effects Research Meeting,2012) (Japanese)
Ozasa K: Radiation effects at low-dose levels andeffects of age at bombing among the atomicbomb survivors. Proceedings of the FY2011
RERF Update Volume 24, Issue 1, 2013

Recent Publications
Radiation Epidemiology Research Meeting.
Tokyo: Radiation Effects Association; 2012, pp
4-5. (Japanese)
Ozasa K, Grant EJ, Cullings HM, Shore RE:
Invited commentary: Missing doses in the Life
Span Study of Japanese atomic bomb survivors.
Am J Epidemiol 2013 (February); 177(6):56973. (RERF Report 15-12)
Sakata R, McGale P, Grant EJ, Ozasa K, Peto R,
Darby SC: Impact of smoking on mortality andlife expectancy in Japanese smokers: A prospective cohort study. BMJ 2012;345:e7093. doi:
10.1136/bmj.e7093 [Epub] (RERF Report 6-11)
Samartzis D, Nishi N, Cologne JB, Funamoto S,
Hayashi M, Kodama K, Miles EF, Suyama A,
Soda M, Kasagi F: Ionizing radiation exposureand the development of soft-tissue sarcomas inatomic-bomb survivors. J Bone Joint Surg Am
2013 (February); 95(3):222-9. (RERF Report
1-11)
Semmens EO, Kopecky KJ, Grant EJ, Mathes RW,
Nishi N, Sugiyama H, Moriwaki H, Sakata R,
Soda M, Kasagi F, Yamada M, Fujiwara S,
Akahoshi M, Davis S, Kodama K, Li CI: Relationship between anthropometric factors, radiation exposure, and colon cancer incidence in theLife Span Study cohort of atomic bomb survivors. Cancer Causes Control 2013 (January);24(1):27-37. (RERF Report 27-11)
Sera N, Hida A, Imaizumi M, Nakashima E,
Akahoshi M: The association between chronic
kidney disease and cardiovascular disease risk
factors in atomic bomb survivors. Radiat Res
2013 (January); 179(1):46-52. (RERF Report
20-11)Sugiyama H, Ozasa K, Tanaka J, Kakehashi M,
Tsunematsu M, Takeda N, Arita K, Kamada N:
Childhood cancer incidence and circumstances
regarding diagnosis and treatment in Hiroshima
prefecture, 2004-2008. Hiroshima Igaku [JHiroshima Med Assoc] 2012 (November);
65(11):685-95. (Japanese)

update 34
KH, Bennett WP, Alavanja MCR, Welsh JA,
Khan MA, Lee A, Diasio R, Edell E, Bungum A,
Jang JS, Yang P, Jen J, Harris CC: EGFR somatic
mutations in lung tumors: Radon exposure andpassive smoking in former- and never-smoking
U.S. women. Cancer Epidemiol Biomarkers Prev
2012 (June); 21(6):988-92.
Takahashi I, Furukawa K, Ohishi W, Takahashi T,
Matsumoto M, Fujiwara S: Comparison between
oscillometric- and Doppler-ABI in elderly individuals. Vasc Health Risk Manag 2013 (March8); 9:89-94. doi: 10.2147/VHRM.S39785 [Epub](RERF Report 3-12)
Tatsukawa Y, Cologne JB, Hsu WL, Yamada M,
Ohishi W, Hida A, Furukawa K, Takahashi N,
Nakamura N, Suyama A, Ozasa K, Akahoshi M,
Fujiwara S: Radiation risk of individual multifactorial diseases in offspring of the atomicbomb survivors: a clinical health study. J Radiol
Prot 2013 (June); 33(2):281-93. (RERF Report28-11)
Wang C, Nakamura S, Oshima M, MochizukiKashio M, Nakajima-Takagi Y, Osawa M,
Kusunoki Y, Kyoizumi S, Imai K, Nakachi K,
Iwama A: Compromised hematopoiesis andincreased DNA damage following non-lethal
ionizing irradiation of a human hematopoietic
system reconstituted in immunodeficient mice.
Int J Radiat Biol 2013 (February); 89(2):132-7.
Yamada M, Shimizu M, Kasagi F, Sasaki H: Reaction time as a predictor of mortality: The Radiation Effects Research Foundation Adult HealthStudy. Psychosom Med 2013 (January 29);
75:154-60. doi: 10.1097/PSY.0b013e3182822b4a[Epub ahead of print] (RERF Report 25-11)
Yasumura S, Hosoya M, Yamashita S, Kamiya K,
Abe M, Akashi M, Kodama K, Ozasa K, for the
Fukushima Health Management Survey Group:
Study protocol for the Fukushima health management survey. J Epidemiol 2012 (September);22(5):375-83.

Taga M, Eguchi H, Shinohara T, Takahashi K, Ito
R, Yasui W, Nakachi K, Kusunoki Y, Hamatani
K: Improved PCR amplification for molecularanalysis using DNA from long-term preserved
formalin-fixed, paraffin-embedded lung cancer
tissue specimens. Int J Clin Exp Pathol 2013
(January); 6(1):76-9. (RERF Report 6-12)
Taga M, Mechanic LE, Hagiwara N, Vahakangas
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RERF Update Volume 24, Issue 1, 2013