Reprinted with the permission by
Swedish Radiation Safety Authority

“Extension Site of Distribution Map
of Radiation Dose, etc.” <http://ramap.
jmc.or.jp/map/eng/map.html>

Sweden-Japan Radioecology

Workshop for Students, 2015
K. Tanoi, S. Miura,
E. Forssell-Aronsson and C. Bradshaw (eds.)

Graduate School of Agricultural and Life Sciences,
The University of Tokyo
NPO Radiation Safety Forum
Department of Radiation Physics, Institute of Clinical Sciences,
Sahlgrenska Academy, University of Gothenburg
Department of Ecology, Environment and Plant Sciences andCentre for Radiation Protection Research,
Stockholm University

Editors
Keitaro Tanoi
Graduate School of Agricultural and Life Sciences,
The University of Tokyo
Satoru Miura
Graduate School of Agricultural and Life Sciences,
The University of Tokyo
Eva Forssell-Aronsson
Institute of Clinical Sciences, Sahlgrenska Cancer Center
Sahlgrenska Academy at University of Gothenburg
Clare Bradshaw
Department of Ecology, Environment and Plant Sciences
Stockholm University© The Editor(s) (if appicable) and the Author(s) 2016
Laboratory of Radio-Plant Physiology, Graduate School of Agricultural and Life Sciences,
The University of Tokyo
1-1-1, Yayoi, Bunkyo-u, Tokyo 113-8657, Japan
Telephone: +81-3-5841-5440
Website: http://park.itc.u-tokyo.ac.jp/radio-plantphys/english.html
Typesetting and design: Riopopo
Printing: Graduate School of Agricultural and Life Sciences, The University of Tokyo
Printed in Japan

Preface

Four years have passed since the accident at the Fukushima-Daiichi Nuclear Power Plant. More than
110,000 people who were evacuated from the area remain separated from their homes. During these 4 years,
the local Fukushima government set up a radiation monitoring system for all agricultural products from thearea. For rice, particularly, a special radiation measuring system was developed to measure rice grain before
it goes to market.
In our graduate school, 40–50 academic staff began in situ research projects immediately after the accident
to trace radioactive materials. Most of these studies rely on volunteer activities. Because our graduate school
includes many specialties in agricultural studies, focusing on cultivated fields, mountains, trees, animals, orfish, researchers with expertise in a variety of fields were gathered together to discuss the measures being
taken to deal with the contaminated environment. For example, in addition to researchers studying rice
breeding, others involved in water or soil studies also came together to discuss radioactive fallout behaviourin the field and to examine the movement of radioactive Cs in rice fields. This was the first time our graduate
school has undertaken a collaborative project of such size.

viiGradually, our researchers have accumulated data on the movement and accumulation of radioactive fallout in the environment. Our initial purpose, as part of our commitment to contributing to the community,
was to show as many people as possible what we have learned about fallout from the nuclear accident, including how it is distributed and how it moves. Seminars open to the public have been held periodically to report
the results obtained from studies in the agricultural environment. The first seminar was held in November
2011, and the eleventh and most recent was held in April 2015. Three parallel lecture series were started, forundergraduate and graduate students and for the general public, to teach how the behaviour and accumulation pattern of radioactive Cs change with time. To allow the students to learn about the behaviour of the
fallout firsthand, several field studies were also carried out at mountain, agricultural, and meadow sites. The
results we obtained during the first 2 years were summarised and e-published through Springer in a booktitled “Agricultural Implications of the Fukushima Nuclear Accident”, which has already been downloaded
more than 50,000 times. A second book with the latest results will be e-published by Springer in 2016. Using
these approaches, our results have been utilised effectively in various ways.
Sometimes the accident at the Fukushima-Daiichi Nuclear Power Plant is compared with the accident
that occurred at Chernobyl. In the case of the Chernobyl accident, it is well known that the first radioactive
measurement of the fallout was performed in Sweden. We found that the study of radio-ecology is highly
advanced in Sweden, whereas before the Fukushima accident, similar research in Japan was limited to somespecial institutes and was not being done at the universities. Most university studies are not widely publicised,
which makes understanding radio-ecology difficult for the younger generation. Therefore, we planned theJapan–Sweden joint workshop on radio-ecology not only for our academic staff but also for the students. We
are very thankful to Prof. Eva Forssell-Aronsson at the University of Gothenburg for accepting our proposal
and to Prof. Andrzej Wojcik and Associate Prof. Clare Bradshaw at Stockholm University for the workshop.
Among the Japanese participants, nine of the students selected were actually carrying out their radioecological studies of Fukushima at the university. Before visiting Sweden, they were taught how to summarise
their data and present at the seminar. Project Associate Prof. Satoru Miura, who kindly accepted the leadership role for this joint seminar, planned well and, with other academic staff, enthusiastically educated each
student. For most students, this was the first time they had discussed their findings with foreign researchers.
As can be seen from their reports, this seminar provided them enormous stimulation and motivation to study
radio-ecology. Of course, the seminar was also valuable to our academic staff, inspiring them to continue ourresearch studies here in Japan at Fukushima.
We would like to express our sincere gratitude again, especially to Prof. Eva Forssell-Aronsson for organizing this wonderful and fruitful seminar. We all expect that we will continue the radio-ecological study ofFukushima for a long time, while also working on improvements to our educational techniques.
Tomoko M. Nakanishi
The University of Tokyo

viii | Sweden-Japan Radioecology Workshop for Students, 2015

University of Gothenburg, Sweden,
1-2 September 2015

On 2 September 2015, 35 scientists from Japan and Sweden met in a joint radioecology workshop at the
Department of Radiation Physics at the University of Gothenburg. The main goal of the workshop was toexchange experiences with the nuclear power plant accidents in Chernobyl in 1986 and in Fukushima in
2011. The participants consisted of the Japanese group, researchers and PhD students from Gothenburg,
researchers from Lund University (Malmo), and others interested in the topic.
The workshop included 19 presentations with related discussions and opportunities for longer discussions
during the lunch and tea/coffee breaks. The day started with two longer presentations: one by Prof Tomoko
Nakanishi on agricultural implications of the Fukushima accident in Japan and the second by Prof Soren
Mattsson, who presented data on long-term studies of the environmental radionuclide distribution and radiology in southwest Sweden after the Chernobyl accident.
This was followed by several presentations on radionuclide distributions and kinetics in fruit, animals, andsoil in Japan, Sweden, and Spain, after the Fukushima and Chernobyl accidents. Some of the presentations
were related to radionuclide kinetics in forests, with important findings in Fukushima Prefecture. Most of the
speakers reported both expected and unexpected findings, demonstrating the importance of future researchin radioecology and the value of proper measurements and studies after a nuclear event.
The final part of the workshop consisted of presentations related to the exposure of humans to radiocaesium, the uranium levels in pit lakes, and the radiobiological effects of low doses of radioiodine.
The workshop also included more general topics. Gunnar Bengtsson, who was Director General of theSwedish Radiation Protection Institute at the time of the Chernobyl accident, gave his personal views on theradioecological competence needed at radiation accidents, based on his experiences at that time. The discussion revealed that this issue is of even greater importance in both Japan and Sweden today.
The previous day, 1 September 2015, the Japanese and Gothenburg groups held a more informal program
including a general presentation on the research being conducted in Gothenburg and visits to several laboratories. The afternoon was spent in the Gothenburg Botanical Garden, one of Europe’s largest at 175 hectares,
and the Anggardsbergen Nature Reserve, where we compared Swedish and Japanese flora and fauna. The
original plan to visit some sampling sites in the region had to be abandoned due to heavy rain.
The days we spent together demonstrated the importance of scientific exchange for students and scientists,
and I am convinced that the workshop has led to new research ideas and new contacts for future collaboration.
Eva Forssell-Aronsson
University of Gothenburg

Preface | ix

Stockholm University, Sweden,
3-4 September 2015

For two days in early September, 2015, twenty-five scientists from Japan and Sweden came together toexchange ideas, results and experiences in the field of radioecology. The two countries have in common thatthey have both been affected by a large accident at a nuclear power plant: in Japan, the accident at Fukushima
Dai-ichi in 2011; in Sweden, the accident at Chernobyl in the former USSR in 1986. In both cases, thelonger term problems are caused by the persistance of 137Cs in the environment, particularly in terrestrial ecosystems. One of the main aims of the workshop was therefore to compare how these accidents have affected
human and non-human populations in these two countries and to see if we could learn from each other.
The workshop started with two overviews of the post-accident radioecological situation in Japan and Sweden. Leif Moberg, former Research Director at the Swedish Radiation Safety Authority summarised spatial
and temporal patterns of environmental contamination from Chernobyl, doses to the Swedish population
and actions, countermeasures and dose limits that were decided after the accident. Keitaro Tanoi presented
the equivalent situation after the Fukushima accident, revealing many similarities in the issues confronted by
the two countries, but also some differences in the way the countries had dealt with these issues. He also gave
an overview of the impressive amount of radioecological research now being carried out in the Fukushima
area to understand radionuclide transfer in the environment and to humans.
The rest of the workshop was divided into the two broad themes of ’Wildlife’ and ’Plant Uptake’. The main
issue for wildlife was 137Cs contamination, and talks ranged from moose, boars, bears and frogs in Sweden
to fish and other marine species in Japan. In most cases, a central concern was consumption of contaminatedwildlife by humans, although doses to the animals themselves was also considered important. After lunch,
there were a series of talks about uptake of radionuclides to crops and other plants. Here the focus was moreon mechanistic uptake studies and different types of remediation. The quality of the talks was very high, andthe Masters and PhD students should particularly be congratulated for their excellent presentations.
During the day there was plenty of time for discussions, which ranged from detailed scientific issues tobroader questions to do with the communication of post-accident decisions and radiation risks, somethingboth countries have grappled with.
On the last day, the group visited the Forsmark Nuclear Power Plant to learn about the Swedish systemof nuclear waste management and the 10-year site investigation programme being carried out prior to thebuilding of a geological repository for high level nuclear waste.
I hope that this workshop will lead to future exchange of ideas and even collaborations between the twocountries; we have much to learn from each other!
Clare Bradshaw
Stockholm University

x | Sweden-Japan Radioecology Workshop for Students, 2015

Contents

Preface ....................................................................................................................................... ⅶ
Chapter 1 Introduction .......................................................................................................... 1
Satoru Miura
Chapter 2

Programme and Participants ............................................................................... 7
Sweden-Japan Workshop on Radioecology for Students, 2015 ............................. 8
Participants list ...................................................................................................... 10

Chapter 3 Workshop at the University of Gothenburg ........................................................ 13
Orientation of Joint Japan Sweden Radioecology
Workshop at the University of Gothenburg
1. Overview of department activities ................................................................. 15
Eva Forssell-Aronsson
2. Environmental radioactivity research at the department of radiation physics– Introduction to Joint Japan Sweden Radioecology Workshop – ................... 19
Mats Isaksson
3.1
3.2

3.3

3.4

3.5

Agricultural implications of Fukushima nuclear accident ........................ 34
Tomoko M. Nakanishi
Studies in environmental radiology
in South-West Sweden after the Chernobyl accident ............................... 55
Sören Mattsson
Analysis of the radiocaesium fixation process in soil using radioactivity
monitoring data on spinach from Fukushima ............................................ 74
Nobuko Mitsuoka, Naoto Nihei, Sho Shiozawa,
Shuichiro Yoshida, Kazuhiro Nishida
Temporal change in radiocesium concentration of peaches
cultivated in Fukushima Prefecture ........................................................... 88
Kyoko Ichikawa, Daisuke Takata, Mamoru Sato, Eriko Yasunaga
Monitoring inspection for radiocaesium in agricultural, livestock,
forest and fishery products in Fukushima Prefecture ................................ 96
Naoto Nihei, Keitaro Tanoi, Tomoko M. Nakanishi

xi

3.6

Penetration of cesium, silver and other metals in soils
with examples from the Fukushima accident ............................................. 108
Gunnar Bengtsson
3.7 Spatial and vertical distribution of fall-out 137Cs in Sweden ................... 115
Mats Isaksson
3.8 Caesium contamination in the Swedish town Gävle eleven years
after the Chernobyl accident and some unexpected findings .................... 129
Robert R. Finck
3.9 Radio cesium fixation process to soil analyzed
by monitored radioactivity data of spinach in Fukushima ......................... 149
J. Mantero, G. Manjón, I. Vioque, R. García-Tenorio
3.10 Radioecology competence needs at radiation accidents– the case of the Chernobyl accident management in Sweden ................... 158
Gunnar Bengtsson
3.11 Application of the in-growth core method to investigate caesium
absorption in tree roots in a northern forest in Fukushima ........................ 164
Osamu Hashimoto
3.12 Spatiotemporal variation of radiocaesium on the forestfloor
in mixed deciduous forests in Fukushima, Japan ........................................ 173
Momo Takada, Toshihiro Yamada, Toshinori Okuda
3.13 Predicting the future radiocesium distribution in Fukushimafrom the distribution of global fallout in forested areas in Japan ............... 174
Satoru Miura
3.14 Variability in Chernobyl deposited Cs-137
and its influence on the human exposure .................................................... 185
Christian Bernhardsson
3.15 Radio cesium fixation process to soil analyzed
by monitored radioactivity data of spinach in Fukushima ......................... 195
Elis Holm
3.16 Uranium levels in mining lakes in Southern Sweden ................................. 211
Rimon Thomas, Juan Mantero, Mats Isaksson, Christoffer Rääf,
Eva Forssell-Aronsson, Elis Holm
3.17 Biokinetics and radiobiological effectsof low dose exposure from radiohalogens in rodents ................................. 217
Johan Spetz, Britta Langen, Eva Forssell-Aronsson
Chapter 4 Workshop at Stockholm University ..................................................................... 229
4.1

4.2
4.3

The Chernobyl accident– consequences and radiation risks in Sweden .......................................... 234
Leif Moberg
Agricultural implications of Fukushima nuclear accident ........................ 249
Tomoko M. Nakanishi
Monitoring of 137Cs in large terrestrial animals in Sweden ..................... 251
Robert N. Weimerxii | Sweden-Japan Radioecology Workshop for Students, 2015

4.4

Radiocaesium contamination in wild boars ............................................... 258
Keitaro Tanoi
4.5 Wetland radioecology post-Chernobyl
and radiation doses to amphibians ............................................................. 268
Karolina Stark
4.6 Current conditions of the fisheries, radioactive contamination ofseafood, and fish ecology on the fishing grounds of Fukushima .............. 280
Tomoya Hori, Takuji Noda, Toshihiro Wada, Takashi Iwasaki,
Hiromichi Mitamura, Nobuaki Arai
4.7 Role of trophic transfer in benthic ecosystems off Fukushima .................. 281
Clare Bradshaw
4.8 Understanding consumer purchasing intentions towards
salted salmon produced in Miyagi prefecture, Japan ................................. 285
Takashi Suzuki, Taro Oishi, Hisashi Kurokura, Nobuyuki Yagi
4.9 Long-term desorption kinetics of Cs from contaminated soil .................. 295
Kento Murota, Takumi Saito
4.10 Interception and Storage of Wet Deposited Radionuclides in Crops ...... 303
Stefan B. Bengtsson
4.11 Comparing Cs dynamics in two rice cultivars,
Milyang23 and Akihikari, by tracer experiments ...................................... 315
Shuto Shiomi, Tatsuya Nobori, Natsuko I Kobayashi,
Keitaro Tanoi, Tomoko M Nakanishi
4.12 The characterisation of caesium accumulation in wild radish ................... 326
Nanami Oshima, Maki Katsuhara, Hiroaki Setoguchi
4.13 The impact of potassium fertilisation:
Investigation using a radioisotope tracer experiment ................................ 340
Natsuko I. Kobayashi, Ryohei Sugita, Tatsuya Nobori, Ryosuke Ito,
Keitaro Tanoi, Tomoko M. Nakanishi
4.14 Really long term radiological assessment of ecosystems and humans ...... 348
Ulrik Kautsky
4.15 Visit to Forsmark ........................................................................................ 364
Chapter 5 Student Reports .................................................................................................... 367
5.1
5.2
5.3
5.4
5.5

Attending the Japan-Sweden workshop ..................................................... 368
Nobuko Mitsuoka
My first workshop on radioecology ............................................................ 371
Kyoko Ichikawa
A wonderful experience in Sweden ............................................................. 373
Osamu Hashimoto
What I learned at the Japan–Sweden workshop ........................................ 375
Momo Takada
Report on the Japan-Sweden Workshop .................................................... 377
Tomoya HoriContents | xiii

5.6
5.7
5.8
5.9

Long-term desorption kinetics of Cs from contaminated soil .................. 379
Kento Murota
Importance of international communication among researchers ............. 381
Suzuki Takashi
What I felt throughout the Japan-Sweden workshop ................................ 384
Shuto Shiomi
What I learned in Japan–Sweden workshop, 2015 ..................................... 386
Nanami Oshima

Chapter 6 Photographs of Activities ..................................................................................... 389
Day1 ...................................................................................................................... 390
Day2 ...................................................................................................................... 394
Day3 ...................................................................................................................... 398
Day4 ...................................................................................................................... 402
Postscript ................................................................................................................................... 406
Appendix 1 Statens strålskyddsinstitut informerar om det radioaktiva nedfalletfrån kärnkraftsolyckan i Tjernobyl ...................................................................... 407
Appendix 2 Efter Tjernobyl? ................................................................................................... 412

xiv | Sweden-Japan Radioecology Workshop for Students, 2015

Chapter 1

Introduction

Introduction
Satoru Miura

The University of Tokyo

Purpose of the workshop
This report is a record of the “Sweden-Japan Radioecology Workshop for Students, 2015” organised by the
University of Tokyo and the NPO Radiation Safety Forum and co-hosted by the University of Gothenburg
and Stockholm University. The workshop was held 4.5 years after the Fukushima Daiichi nuclear power plant
accident so that Japanese researchers working on restoring agriculture and the environment after a radiation disaster could exchange information with Swedish researchers with experience in demining radioactive
contamination caused by the Chernobyl nuclear power plant accident. We thought that it would be goodfor scientists to think and talk outside Japan in an objective manner during the transition from the initialemergency to a steady state following the accident. The second goal was to provide educational opportunities for students. In 2013, the Graduate School of Agricultural and Life Sciences, at the University of Tokyo(one of the organisers), launched a practical education program on radiation in the ‘agricultural environment’and ‘food safety’ after the Fukushima disaster. We emphasise field work at Fukushima and the program
mission, which is to educate students who are interested in environmental radioactive contamination andare motivated to help restore agriculture and the environment after such disasters. We have prioritised theneed to foster human resources with a broad knowledge of radiation to ensure a precise response to the issues of long-lasting radiation contamination and to prepare for any future radiation accident. The number ofnuclear power plants worldwide is still increasing. We thought that a research workshop of this kind would
be effective for teaching researchers to act collaboratively with scientists in other countries, since radioactive
contamination is spread trans-nationally. The workshop, entitled “Sweden–Japan Radioecology Workshop
for Students, 2015”, was made possible by the whole-hearted cooperation of the University of Gothenburg
and Stockholm University and was held in Gothenburg and Stockholm. We are proud of this unique opportunity for research exchange with European countries after the Fukushima nuclear power plant accident,
targeting education for young students.

History of man-made radiation
Henri Becquerel and Pierre and Marie Curie were the first to recognise radiation, with their discoveriesoccurring at the end of the nineteenth century. Early in the twentieth century, mankind discovered the enormous energy retained invisibly within the atom nucleus. The use of energy as a weapon was first conceived
in the 1930s, and some 50 years after the discovery of radiation, nuclear weapons were first used in 1945,
and large amounts of radiation were released into the natural environment. Enormous amounts of radiation
continued to be released into the atmosphere, commensurate with the escalated competition to develop
nuclear weapons. Ten years after the use of atomic bombs at Hiroshima and Nagasaki, atomic power generation technology was put into practice. In the 50 years since then, mankind has experienced two severe (Level
7) nuclear power plant accidents. If we include less serious accidents that could easily have been worse, then

2 | Sweden-Japan Radioecology Workshop for Students, 2015

accidents that released artificial radiation on a large scale could have occurred approximately every 10 years.
Although the instantaneous explosion of nuclear weapons is terrible, the damage caused by prolonged exposure to radiation from nuclear power plant accidents is also serious and no fundamental mitigation countermeasures have been developed.
The radioactive accident at the Fukushima Daiichi nuclear power plant happened 25 years after the accident at Chernobyl. Japanese society had not learned the valuable lessons experienced in Europe. Listening
to the talks by senior people who led the countermeasures in Sweden in 1986, I felt a sense of deja vu withrespect to our struggles in Fukushima in 2011. Although this situation is undesirable, human society has
still not learned how to address radiation issues even after experiencing several extremely severe radioactive
disasters. Consequently, I have realised how important it is for us in Japan to share the lessons of Fukushima
with the international community, which experienced the Chernobyl disaster.
In 2011, immediately after the Fukushima Daiichi nuclear power plant accident, the Ministry of Agriculture, Forestry and Fisheries of Japan and the local government of Fukushima Prefecture, many research institutes, universities, and private companies launched full-scale efforts to combat radiation contamination, andthey have succeeded in decontaminating areas and establishing practical countermeasures, such as upsidedown deep tillage to bury radiocaesium below the rhizosphere and potassium application to reduce caesium
uptake by paddy rice. These measures have enabled farmers to recommence agricultural production of many
crop plants to a considerable extent. Nevertheless, radioactive contamination of the natural environment,
including forests and the ocean, still affects extensive areas. We have not developed fundamental countermeasures for environmental rehabilitation. We believe that it is impossible to recover radiocaesium from the open
ocean. It might also be impossible to decontaminate radioactive materials from forests because of the verylarge area involved and the need to dispose of vast amounts of decontaminated materials removed from forests. Therefore, we have to prepare to deal with a radiation-contaminated environment on a long-term basis.
Japan has a high population density and there are many residents in intermountain regions, where people
depend on agriculture or forestry. In April 2014, the evacuation order for a small town within 20 km of the
Fukushima Daiichi nuclear power plant was lifted and people have started to return home. However, toresume their lives, they will need to learn how to utilise cropland and forests that have residual radioactive
contamination. Many questions that require scientific knowledge and technological countermeasures remain
to be solved. The radioactive exhaust from the Chernobyl nuclear power plant was first detected by the Forsmark nuclear power plant in Sweden, as discussed below. I can only imagine the extent of the social chaos in
Sweden at that time. Although environmental radioactive contamination from the accident remains, Sweden
seems to have adapted to the situation successfully. Japanese society is in a transitional phase, between thestate of emergency right after the Fukushima radiation disaster and a future steady-state, and must learn fromthe experience of Swedish society, which has dealt with radiation and radioactive contamination for morethan 25 years.

Education program for students
Another aspect of the student education program was based on a long-held motivation. Although mankind has been able to make practical and effective use of atomic power for only 70 years, we have experienced
large-scale nuclear accidents roughly every 10 years, as mentioned above. Ten years is a long time in the modern world, in which everything changes very quickly. Many people who did not experience the radiation disaster from the Fukushima nuclear power plant first-hand might forget the severity of the nuclear accident in
10 years. However, the numbers of nuclear power plants and their cumulative production of electrical energy
Chapter 1

Intoroduction | 3

are still increasing. History tells us that we cannot avoid unanticipated accidents or human error, no matter
how thorough the measures we take to prevent accidents. I think that this is the most important lesson fromboth the Chernobyl and Fukushima radiation accidents. I cannot count how often I heard newscasters use
the word “unanticipated” in 2011. Atomic power produces a great deal of concentrated energy comparedwith hydroelectric power or combustion and it also produces large amounts of radioactive material; thesefactors underlie the severity of nuclear accidents and represent the reason why careful, thorough preparationis needed. This is true for both off-site environmental contamination and on-site contamination around thenuclear power plant.
I sincerely hope that the students participating in this workshop will serve in a bridging capacity by transferring the experience and wisdom that they gain to the next generation when they are faced with a nuclear
power plant accident. In fact, many leading researchers from Europe and the International Atomic Energy
Agency have visited Fukushima over the last 5 years to pass on the lessons they learned from the Chernobyl
accident to the Japanese. Some of them were graduate students, postdoctoral fellows, or up-and-coming
educators in 1986. We believe that a discussion of the common challenges faced in terms of radioecology andradiation protection, through sharing the 30-year experience of the Chernobyl accident gained in Sweden
and the 5-year experience of the Fukushima accident gained in Japan, would be valuable for young people
and educators from both countries.

Program outline
This workshop report has six sections. The next chapter outlines the program and schedule, and lists thepeople involved. Chapter 3 consists of the abstracts and presentation slides from the workshop seminar in
Gothenburg and Chapter 4 contains the same material from the Stockholm session. Some authors did not
submit some or all of the presented material because their data are pending publication. I thank the 25 authors who agreed to make their contributions public.
Our plans were ambitious, because the party from Japan would visit universities in Gothenburg and Stockholm, which are 400 km apart, in 4 days while also fitting in a 1-day workshop seminar and another day ofobservation activities in each city. The University of Gothenburg and Stockholm University were the leading education and research centres in Sweden after the Chernobyl accident, and thus provided the optimal
program. The seminar titles indicate that, although the focus was on radioecology, a wide range of topics onradiation were included.
On Day 1 in Gothenburg, we had the opportunity to observe various radiation research facilities in the
Department of Radiation Physics at the University of Gothenburg. We found the story of the whole-bodyradiation counter in the basement of the Sahlgrenska Cancer Centre to be very interesting. The shield forthe whole-body counter was made from very old iron, which was first used in the construction of HMS
Vanguard, the last English battleship made (in the middle of the 20th century), and then reused to build adestroyer that was sunk during the Falkland Islands War in 1982. The need for mobile, car-borne radiationmeasuring instruments carried in a small pick-up truck was demonstrated. Dr. Juan Mantero Cabrera gave aninteresting talk on studies using state-of-the-art alpha-ray spectrometry to determine natural radiation fromuranium and thorium in pit lake water, which is a current radiation issue in Sweden. The half-day excursions
to Gothenburg Botanical Garden, one of the largest botanical gardens in Europe, and to Änggårdsbergen
Nature Reserve, helped us to relax while walking in natural environments that are not very different fromthose in Japan (albeit that Swedish gardens are very different from Japanese gardens).
Finally, on Day 4 in Stockholm, we were able to observe the sub-marine, final repository of low- and inter-4 | Sweden-Japan Radioecology Workshop for Students, 2015

mediate-level radioactive waste, which has been in operation since 1988, as well as the environmental monitoring sites above the planned construction site of the final geological repository for high-level radioactive
waste. Both of these sites are located near the Forsmark nuclear power plant. I was very impressed to learn
that the final storage facility has been in operation for more than 25 years. In Japan, we cannot avoid this“backend issue” of atomic power utilisation. Dr. Sara Nordén, an ecologist at Svensk Kärnbränslehantering
Aktiebolag (SKB) a Swedish nuclear fuel and waste management company, kindly showed us the monitoringsites in an old spruce forest, as well as a reserve for frogs and orchids in the Labbo Forest wetland. Since myresearch examines forest environments, I found the old spruce forest and its fluffy understory vegetation tobe especially interesting. The detailed monitoring results of the initial environmental conditions are available
to the public on the SKB web page ( http://www.skb.se/publication/2222643/TR-10-01.pdf ). Chapter 6
consists of photographs that outline some of the observation activities undertaken. There are no photographsof the final repository for low- and intermediate-level radioactive waste because no photography is allowed
at the site.

Acknowledgements
It was my great pleasure to lead this challenging mission. I was able to give more than a passing thought toadvising students and facilitating interactions between Swedish educators and scientists – from the perspective of a scientist – as well as advise on the social responsibility that goes with the utilisation of atomic power
given its potential consequences.
I sincerely thank Dr Tomoko M. Nakanishi and Dr Keitaro Tanoi for granting me this invaluable opportunity to plan and coordinate this workshop, which would not have been successful without the unqualified
cooperation of the universities involved. I am profoundly grateful to Dr Eva Forssell-Aronsson, (University
of Gothenburg), as well as Dr Andrzej Wojcik and Dr Clare Bradshaw who planned and hosted the workshops at their respective universities. We appreciate the many participants of each university, the academic
staff from neighbouring universities, and the individuals formerly in charge of the Swedish Radiation Safety
Authority (SSM) who willingly responded to calls from the hosts. We also thank all of the staff and students
who helped the hosts to prepare and manage the workshops. The names of all of the contributors are listed
in the following outline and I thank them all.
Finally, I would like to thank the students who participated in the workshop in such a positive manner.
They appeared to benefit from it substantially. Chapter 5 contains their reports and summarises what theylearned together with their feelings and thoughts. They were stimulated by their exchanges with both seniorleading scientists and young scientists in Sweden. I have no doubt that this workshop gave the students anopportunity to learn beyond the laboratory setting. Hopefully, this successful exchange is the first step towards continuous international education and collaborative research activities to combat radiation problems
after nuclear power plant disasters and to prepare for future radiation accidents. Society in Sweden and Japan
will continue to strengthen measures against nuclear disasters based on their experiences in recovering fromthe worst ever disasters at Chernobyl and Fukushima. I am convinced that both countries and their respective
universities could become a core group with respect to education and research on radioecology and radio-agriculture. I hope that this is the beginning of a strong partnership between universities in Sweden and Japan.

Chapter 1

Intoroduction | 5

Chapter 2

Programme and Participants

Sweden-Japan Radioecology Workshop for Students, 2015
Overview
Date:

September 1-4, 2015

Venue:

University of Gothenburg, Stockholm University

Outlines of programme:
Sep 1stSep 2ndSep 3rdSep 4thOrientation
Facility tour at Department of Radiation Physics, Institute of clinical sciences, University ofGothenburg and discussions on sampling etc.
Half day field walk in Gothenburg botanical garden and Änggårdsbergen Nature Reserve
Dinner with seminar participants
Workshop Seminar on Radioecology at University of Gothenburg
Workshop Seminar on Radioecology at Stockholm University– Wildlife and plant uptake –Welcome dinner at Centre for Radiation Protection Research
Field trip to Forsmark radioactive waste repository and the surrounding ecosystems guided
by Dr. Sara Nordén, an ecologist at Forsmark, SKB

People involved
Coordinator and academic staff of mission from Japan:

Project Associate Professor Satoru Miura* (Leader of Japanese visiting group)
Associate Professor Keitaro Tanoi
Associate Professor Naoto Nihei
Assistant Professor Natsuko I. Kobayashi
Laboratory of Radio-Plant Physiology, Radioisotope Center
Graduate School of Agricultural and Life Sciences, the University of Tokyo

Host coordinators in Sweden:

Professor Eva Forssell-Aronsson
Department of Radiation Physics
Institute of Clinical Sciences, Sahlgrenska Cancer Center
Sahlgrenska Academy at University of Gothenburg* Currently at Dapartment of Site Environment, Foresry and Forest Products Research Institute

8 | Sweden-Japan Radioecology Workshop for Students, 2015

Professor Andrzej Wojcik
Centre for Radiation Protection Research
Department of Molecular Biosciences, The Wenner-Gren InstituteStockholm University
Associate Professor Clare Bradshaw
Department of Ecology, Environment and Plant Sciences
Stockholm University

Contributors:

Atsushi Hirose, Ryohei Sugita, Shuto Shiomi, Sophie-Asako Xerri, Utako Shinohara, Kazue Anzai (The
University of Tokyo), Eriko Kanazawa (NPO Radiation Safety Forum), Britta Langen, Juan Mantero Cabrera, Johan Spetz, Rimon Thomas, staff of Department of Radiation Physics (Gothenburg University),
Dan Aronsson (Ringhals Nuclear Power Plant), Karolina Stark, Maria Greger, Lena Konovalenko (Department of Ecology, Environment and Plant Sciences, Stockholm University), staff of Prof. Wojcik’s laboratory (Stockholm University), Sara Nordén, Ulrik Kautsky,communications staff (Swedish Nuclear Fuel andWaste Management Company, SKB), Stefan Bengtsson (Formerly at Swedish University of Agricultural
Sciences and Fukushima University), Leif Moberg, Pål Andersson (Swedish Radiation Safety Authority).

Special adviser:

Professor Tomoko M. NakanishiLaboratory of Radio-Plant Physiology, Radioisotope Center
Graduate School of Agricultural and Life Sciences, University of Tokyo

Chapter 2

Programme and Participants | 9

Participants list in Workshop Seminars
in Gothenburg and in Stockholm
Japan side (participated in both workshops) :Osamu Hashimoto, Master student
Graduate school of Agricultural and Life Sciences,
The University of Tokyo
Tomoya Hori, PhD student
Graduate school of Informatics, Kyoto University
Kyoko Ichikawa, Master student
Graduate school of Agricultural and Life Sciences,
The University of Tokyo
Natsuko I. Kobayashi, Assistant professor
Graduate school of Agricultural and Life Sciences,
The University of Tokyo
Nobuko Mitsuoka, Master student
Graduate school of Agricultural and Life Sciences,
The University of Tokyo
Satoru Miura, Project associate professor
Graduate school of Agricultural and Life Sciences,
The University of Tokyo
Kento Murota, Master student
School of Engineering, The University of Tokyo
Tomoko M. Nakanishi, Professor
Graduate school of Agricultural and Life Sciences,
The University of Tokyo
Naoto Nihei, Associate professor
Graduate school of Agricultural and Life Sciences,
The University of Tokyo
Nanami Oshima, Undergraduate student
Faculty of Integrated Human Studenties,
Kyoto University

10 | Sweden-Japan Radioecology Workshop for Students, 2015

Shuto Shiomi, Master student
Graduate school of Agricultural and Life Sciences,
The University of Tokyo
Takashi Suzuki, PhD student
Graduate school of Agricultural and Life Sciences,
The University of Tokyo
Keitaro Tanoi, Associate professor
Graduate school of Agricultural and Life Sciences,
The University of Tokyo
Momo Takada, PhD student
Graduate School of Integrated Arts and Sciences /Faculty of Integrated Arts and Sciences,
Hiroshima University

Gothenburg, Sweden:
Sara Almgren, Dr
Ringhals Nuclear Power Plant, Väröbacka
Magne Alpsten, Professor
Department of Radiation Physics,
University of Gothenburg

Juan Mantero Cabrera, Dr
Department of Radiation Physics,
University of Gothenburg
Sören Mattsson, Professor
Department of Medical Radiation Physics,
Lund University / Malmö

Dan Aronsson, Dr
Ringhals Nuclear Power Plant, Väröbacka

Jenny Nilsson, Dr
Department of Radiation Physics,
University of Gothenburg

Gunnar Bengtsson, Dr
Former Director general of Swedish Radiation
Protection Institute (SSI)

Christopher Rääf, Associateiate professor
Department of Medical Radiation Physics,
Lund University / Malmö

Christian Bernhardsson, Dr
Department of Medical Radiation Physics,
Lund University / Malmö

Johan Spetz, PhD student
Department of Radiation Physics,
University of Gothenburg

Robert Finck, Dr
Department of Medical Radiation Physics,
Lund University / Malmö (Previously SSM,
Swedish Radiation Safety Authority)

Rimon Thomas, PhD student
Department of Radiation Physics,
University of Gothenburg

Eva Forssell-Aronsson, Professor
Department of Radiation Physics,
University of Gothenburg

Karl Östlund, PhD student
Department of Medical Radiation Physics,
Lund University / Malmö

Elis Holm, Professor
Department of Radiation Physics,
University of Gothenburg
Mats Isaksson, Professor
Department of Radiation Physics,
University of Gothenburg
Britta Langen, Dr
Department of Radiation Physics,
University of Gothenburg
Afrah Mamour, MSc
Department of Radiation Physics,
University of Gothenburg

Chapter 2

Programme and Participants | 11

Stockholm, Sweden:Pål Andersson, Dr
Swedish Radiation Safety Authority
Stefan Bengtsson, Dr
Formerly at Swedish University of Agricultural
Sciences and Fukushima University
Clare Bradshaw, Associate professor
Department of Ecology, Environment and Plant
Sciences, Stockholm University
Maria Greger, Associate professor
Department of Ecology, Environment and Plant
Sciences, Stockholm University
Ulrik Kautsky, Dr
Swedish Nuclear Fuel and Waste Management
Company (SKB)
Lena Konovalenko, Dr
Department of Ecology, Environment and Plant
Sciences, Stockholm University and Facilia
Leif Moberg, Dr
Former Research Director at the Swedish Radiation Safety Authority.
Sara Nordén, Dr
Swedish Nuclear Fuel and Waste Management
Company (SKB)
Karolina Stark, Dr
Department of Ecology, Environment and Plant
Sciences, Stockholm University
Synnove Sundell-Bergmann, Professor
Swedish University of Agricultural Sciences(SLU)
Robert Weimer, PhD student
Swedish University of Agricultural Sciences(SLU)

12 | Sweden-Japan Radioecology Workshop for Students, 2015

Chapter 3
Workshop at the University of Gothenburg

Orientation of Joint Japan Sweden Radioecology
Workshop at the University of Gothenburg
Date:

September 1, 2015

Venue:

Sahlgrenska Cancer Center, Sahlgrenska Academy at University of Gothenburg

1. Overview of department activities
Eva Forssell-Aronsson, proffessor(Department of Radiation Physics, Institute of Clinical Sciences)

2. Environmental radioactivity research at the department of radiation physics– Introduction to Joint Japan Sweden Radioecology Workshop –Mats Isaksson, proffessor(Department of Radiation Physics, Institute of Clinical Sciences)

14 | Sweden-Japan Radioecology Workshop for Students, 2015

1. Overview of department activities
Eva Forssell-Aronsson

Overview of department activities

Eva Forssell-Aronsson
Dept of Radiation Physics
Inst of Clinical Sciences
University of Gothenburg

Gothenburg Sept 1, 2015

Sweden
9.7 million inhabitants

Gothenburg
550 000 inhabitants

Chapter 3

Workshop at the University of Gothenburg | 15

Sahlgrenska Academy at the University of Gothenburg
Sahlgrenska University Hospital

Sahlgrenska Academy at the University of Gothenburg
Sahlgrenska University Hospital

16 | Sweden-Japan Radioecology Workshop for Students, 2015

Staff
Professors/senior lecturers
Researchers
Postdocs
PhD students
Assistant researchers
Technicians

6 (2 part-time)
3
4
20
4
1

Assoc researchers at univ. hospital
Adjunct senior lecturer

101

Education
Medical physics program, 5 y (300 credits)
Mathematics and general physics (2 y)Basic radiation physics (1 y)Applied radiation physics (1 y)Clinical radiation physics (0.5 y)
Master thesis (0.5 y)

Master program in radiation safety, 2 y (60 credits)
Radiology technicians(15 credits)

Chapter 3

Workshop at the University of Gothenburg | 17

Education - subjects
Radiation sources (Ionozing and non-ionizing radiation)
Nuclear physics
Interaction of radiation with matter
Detectors and measurement techniques
Dosimetry of ionizing radiation
Radiation biology
Environmental radiology
Radiation protection
Emergency preparedness and radiation protection
Medicine for physicists
Nuclear magnetic resonance imaging
Nuclear medicine (imaging and therapy)
Radiology (imaging)Radiotherapy

18 | Sweden-Japan Radioecology Workshop for Students, 2015

2. Environmental radioactivity researchat the department of radiation physics
Mats Isaksson

Environmental radioactivity
research at the department ofradiation physics
Introduction to Joint Japan Sweden Radioecology
Workshop 1 Sept. 2015, Gothenburg

Mats Isakson, prof.
Dep. of Radiation Physics

http://battleshiphmsvanguard.homestead.com/

ASSESSMENT OF INTERNAL DOSES IN
EMERGENCY SITUATIONS

Chapter 3

Workshop at the University of Gothenburg | 19

Whole body counting 1
Palmergeometry
Partly shielded detector
Totally shielded detector

3

Whole body counting 2

4

20 | Sweden-Japan Radioecology Workshop for Students, 2015

Whole body counting 3

5Whole body counting 4
Geometry dependent!
BOMAB - BOttle MAnnikin
ABsorber phantom(Bush 1949)
Mathematical calibration isan alternative

6

Chapter 3

Workshop at the University of Gothenburg | 21

Whole body counting 5This is the
IRINAphantom

Whole body counting 6
This is also the
IRINA phantom

22 | Sweden-Japan Radioecology Workshop for Students, 2015

Effects of biokinetics 1

Effects of biokinetics 2

Chapter 3

Workshop at the University of Gothenburg | 23

Thyroid uptake measurements
Intercomparison exercises
Applications in emergency preparedness
Calibration of uptake meters
Dose assessments

MOBILE MEASUREMENTS

24 | Sweden-Japan Radioecology Workshop for Students, 2015

Activities
Field gamma spectrometry
Car borne measurements

2347

1938

3717

2522

1864

1976

457

1010
2792
778

2751

4064
1560
3119
1660

2896
1050

3062

1510
1937

1264

2466

296

571
2078

1130
1200

Scale:
010

20km

MODELLING AND FIELDSTUDIES

Chapter 3

Workshop at the University of Gothenburg | 25

Deposition modelling

Reference sites 1

26 | Sweden-Japan Radioecology Workshop for Students, 2015

Reference sites 2

Vertical migration

Chapter 3

Workshop at the University of Gothenburg | 27

Marine modelling
The Iceland coastal waters, Cs-137
10000

Concentrations

1000

water, Bq/m3
fish, Bq/kg f.w., CF approachsmall fish, Bq/kg f.w.
large fish, Bq/kg f.w.

100

10

1

0,1

0,01

0

2

4

6

8

Years

Pit lakes

28 | Sweden-Japan Radioecology Workshop for Students, 201510

ENVIRONMENTAL DOSEASSESSMENTS

EMERGENCY PREPAREDNESS

Chapter 3

Workshop at the University of Gothenburg | 29

Emergency
preparedness labs

FOI in UmeåSMHI in Norrköping:
SLU in Uppsala
Linköping ‘university:

University of Gothenburg:

SGU in Uppsala

SSM in Stockholm

FOI in Stockholm
Lund university, Malmö
Studsvik AB in Nyköping

Pasture sampling

30 | Sweden-Japan Radioecology Workshop for Students, 2015

Thank you!

Chapter 3

Workshop at the University of Gothenburg | 31

Joint Japan Sweden Radioecology Workshop
at University of Gothenburg
September 1-2, 2015
Location: Department of Radiation Physics (Radiofysikhuset)
Gula Stråket 2 B, Sahlgrenska University Hospital!
32 | Sweden-Japan Radioecology Workshop for Students, 2015

September 2, 2015
Time

Activity

Speaker

08:30

Welcome and introduction

Eva Forssell-Aronsson

08:45

Agricultural implications of Fukushima nuclear accident

Tomoko Nakanishi

09:15

Studies in environmental radiology in South-West Sweden after the
Chernobyl accident

Sören Mattsson

09:45

Radiocesium fixation process to soil analyzed by monitored radioactivity
data of spinach in Fukushima

Nobuko Mitsuoka

10:05

Tea/coffee break

10:30

Temporal change of radiocesium concentration of peach fruits cultivated in
Fukushima Prefecture

Kyoko Ichikawa

10:50

Monitoring inspection for radiocesium in agricultural, livestock, forest andfishery products in Fukushima Prefecture

Naoto Nihei

11:10

Penetration of cesium, silver and other metals in soils with examples fromthe Fukushima accident

Gunnar Bengtsson

11:25

Spatial and vertical distribution of fall-out 137Cs in Sweden

Mats Isaksson

11:45

Caesium contamination in the Swedish town Gävle ten years after the
Chernobyl accident and some unexpected findings

Robert Finck

12:05

Influence of the Fukushima Dai-ichi nuclear accident on Spanish
environmental radioactivity levels

Juan Mantero

12:25

Radioecology competence needs at radiation accidents – the case of theChernobyl accident management in Sweden

Gunnar Bengtsson

12:40

Lunch

13:40

Application of the in-growth core method for understanding cesium
absorption of tree roots in Fukushima northern forest

Osamu Hashimoto

14:00

Spatio-temporal variation of radiocesium on forest floors in mixed
deciduous forests in Fukushima

Momo Takada

14:20

Predicting the future radiocesium distribution in Fukushima from the global Satoru Miura
fallout distribution in forest area in Japan

14:40

Mappings of the deposition around the Fukushima NPP

Karl Östlund

15:00

Modelling the radioecological transfer of 134,137Cs to the Swedish
population

Christoffer Rääf

15:15

Spatial variability of the dose rate from 137Cs and its influence on thehuman exposure – examples from Chernobyl contaminated areas in Russia
and Belarus.

Christian Bernhardsson

15:30

Tea/coffee break

16:00

The effect of dialysis on 137Cs and 131I in man

Elis Holm

16:20

Uranium levels in mining lakes in Southern Sweden

Rimon Thomas

16:40

Biokinetics and radiobiological effects of low dose exposure fromradiohalogens in rodents

Johan Spetz/Britta Langen

17:00 –

General discussion

Chapter 3

Workshop at the University of Gothenburg | 33

3.1 Agricultural implications of Fukushima nuclear accident
Tomoko M. Nakanishi†,1† Presenter: atomoko@mail.ecc.u-tokyo.ac.jp

1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

More than 4 years have passed since the Fukushima Daiichi nuclear power plant accident. More than
110,000 people who were evacuated from the area remain at locations different from where they used to live.
Immediately after the accident, the Graduate School of Agricultural and Life Sciences at Tokyo University
created an independent team from a wide variety of research specialties including soil, vegetation, animal life,
fishing, and forestry. This team entered sites in the affected areas immediately after the accident and initiatedresearch studies. They are continuing their research to determine the effects of the accident on agricultural
fields. Our Graduate School includes many research areas, and many facilities such as meadows, experimental
forests, and farming fields are associated with the school. Employing these facilities, many on-site researchstudies have been conducted in Fukushima Prefecture.
It was important to the Graduate School of Agricultural and Life Sciences that the results of these research studies contribute to the recovery of the affected area; therefore, we have endeavoured to officiallypublish the results. For example, 11 meetings have been held since November 2011 to report research results.
The objective of these meetings was to provide a simple explanation of the results of the research studies sothat the general public could understand them. We published two books about the research on Fukushima,
one through Springer Publishing Company and the other as an easy-to-understand book written in Japanese.
The books were published to allow a wide range of ordinary people to have a correct understanding of the
impact of radioactive material on agricultural, forestry, and fishing products and the countermeasures taken
against radiation exposure.
Based on the scientific data from these studies, we initiated lecture classes for students and for the general public to explain the behaviour and movement of radioactivity in the environment and to provide basic
knowledge about radioactivity. To provide firsthand experience of radio-ecology in the environment for students, we periodically hold open lectures in the contaminated fields or mountains.
A major feature of the radioactive fallout is that radioactive caesium (Cs) has remained at the initial
contact sites and has moved very little since the initial event. In animals, metabolic activity has reduced theradioactivity level over time at a much faster rate than the physical half-life. The biological half-life in animals
was estimated to be less than 100 days. Soil plays a major role in immobilising fallout. When fallout nuclides
are absorbed into the soil, little of the radioactive Cs is taken up by plants growing there. In the mountains,
radioactive Cs was transferred gradually from vegetative litter to soil and subsequently moved very little,
even when the soil was washed with heavy rain. The mechanism of contamination by radioactive nuclides iscompletely different from that of heavy metals.
Similar to the agricultural environments of other Asian countries, Japan is located in a monsoon area, withmany paddy fields used to grow rice. However, the climate and agricultural environment in Japan differ fromthose near Chernobyl; therefore, it is important to gather information regarding the movement and featuresof fallout that are specific to Japan from an agricultural point of view.
It appears that the recovery of the agricultural, forestry, and fishing industries in Fukushima Prefecture will

34 | Tomoko M. Nakanishi

take quite some time, but the Graduate School of Agricultural and Life Sciences at Tokyo University willcontinue to support the recovery of these industries in the future.

Keywords:
Fukushima Daiichi nuclear power plant accident, radiation contamination, agriculture, radio-ecology

3.1 Agricultural implications of Fukushima nuclear accident | 35

Agricultural	  Implica.ons	
  of	
  Fukushima	
  Nuclear	
  Accident	

Tomoko	
  M.	
  Nakanishi	  Graduate	
  School	
  of	
  Agricultural	
  and	
  Life	  Sciences,	
  The	
  University	
  of	
  Tokyo	

1989
December	

:30km from the reactor	

2011 November	
36 | Tomoko M. NakanishiContaminated	
  area:～６％	
  Radioac.ve	
  Cs	
  amount:	  	
  ～1/6	
  Fall	
  out	  distance:～1/10	

Accumulated Annual Radiation Dose- monitored by an airplane	2011	
  Nov.	
  5	
2014	
  Nov.	
  7	

3	

Number	  of	
  People	  Evacua1ng	
  (2015	
  May)	
  112,000	
  by	
  the	
  earthquake	no	
  entry	
cannot	  stay	  2012	
  June	  164,000	
  Peak)	

２０～５０mSv/y	

Restricted	
  Area	  	
  79,000	No	
  entry	
  9100	  	
  families	
  24,000	
  (31%)	
Cannot	  stay	
  8400	  	
  families	
  23,000	
  (29%)	
Prepare	
  for	
  coming	
  back	  10900	
  families	
  32,000	
  (40%)	

Former	  Restricted	
  Area	  19,000	For	  Other	
  Reason	
  14,000	（備考）	

田村市、広野町、	  
楢葉町、川内村、	
  
南相馬市	

福島市、郡山市、	  いわき市など、	  福島県内全域	

60%	
  
	
  
45%	
  
	
  

25-­‐30%	
  
	
  

15%	
   Prepare	
  for	
  coming	
  b4	
ack	
July	
  6,	
  2015	
3.1 Agricultural implications of Fukushima nuclear accident | 37

Project for Fukushima at Graduate School of
Agricultural and Life Sciences
The academic staffs are participating in the following researchgroup to contribute the damaged agriculture by east Japan greatearthquake.
	（１）The influence of high radioactivity on agricultural
products and the possible way for recovery .
① crop production and soils② stock raising & dairy products③ fishery	④ radiation measurement & radiochemistry⑤ field monitoring & science communication（２）Recovery of suffered agriculture① crops production and soils (salt damage, farmland
maintenance, etc.) 	
② biomass production		

Projdects	
  for	  Fukushima	
  conducted	
  at	
  	
  our	
  faculty

Trees,	
  liHers,	
  mushroom	

Fruit	
  trees	

insects	

milk	

Crop	
  and	
  vegetable	
  produc1on	
  
soil	
畑	

Plant	
  species	  38 | Tomoko M. NakanishiWild	
  life	Live	
  stocks	

Crop	
  produc1on	
  in	
  paddy	  soil	  meadow	
Fish	
  

	
  

Soil	  contamina.on	
April	
  21,	  2011	

Farming	
  land	Depth	  	
  (cm)	

Farm	
  land	Vegetable	
  land	0	

-­‐5	-­‐10	

134Cs	
137Cs	-­‐15	

Radioac1vity	
  (Paddy	  Bq/kg)	
land	

Wheat	  	
  land	Wheat	
  ﬁeld	

3.1 Agricultural implications of Fukushima nuclear accident | 39

Radioac.vity	
  movement	
  of	
  Koriyama-­‐City	
  (movement	
  of	
  gravity	
  center)	

Depth from soil surface [cm]	

0	

0	

10	

June 14 center =7.05cm	
Sep. 27 center =7.61cm	

20	

30	

10	

20	

June14～Sep.27	
Cs:moving distance	
5.6 mm		
Rainfall:	
616 mm	40	

(until June 14)	Cs moving distance： 	
21.6 mm		
rainfall： 	
189 mm	

30	

40	

	
50	
0	

5	

10	

15	

Relative radioactivity [%]	

50	
0	

20	

10	

20	

30	

40	

50	

60	

70	

80	

Relative radioactivity [%]	By	
  Prof.	
  S.	
  Shiozawa	
40 | Tomoko M. Nakanishi

A wheat grown in Fukushima

Picture	  of	
  the	  sample（2011/05/16）	
  Wheat field
early in March	

Radioac.vity	
  image	
  by	
  an	
  imaging	
  plate	  (	
  2011/05/20)	
  
	
  

	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  By	
  A.	
  Prof.	
  K.Tanoi	
  Schematic Illusgration of Real-time Radioisotope Imaging System	
radia.on	light	CCD	
  camera	(RRIS)	

FOS	  （Fiber	  op.c	  plate	
  with	  CsI(Tl)	
  Scin.llator）	
  Sugita	  et	
  al.	
  Physics	
  in	
  Medicine	
  and	
  Biology	
  2014;59:837-­‐851	
  Sugita	  et	
  al.	
  Journal	
  of	
  Radioanaly.cal	
  and	
  Nuclear	
  Chemistry	
  2013;	
  298:	
  1411-­‐1416	
  Kanno	  et	
  al.	
  Philosophical	
  Transac.ons	
  of	
  The	
  Royal	
  Society	
  B	
  2012;367:1501-­‐1508	
  	

3.1 Agricultural implications of Fukushima nuclear accident | 41

1st	
  genera.on	

Development	
  of	
  the	
  system	
In Dark	
For a short time, a few
hours	

2nd	
  genera.on	

Humidity	
  &	
  tmeperature	
  control

Under Light and dark 	
Light sealed box for plants
sealed with 50μm Al sheet.	
preferable for high energy βrays or γ-rays ( 32P・109Cd・137Cs,etc.）	

3rd	
  genera.on	
Light on, off/ Camera off, on	LED for plants	

LED	
  

FO
S	
  

Light is off when the camera is on
Light shield is not necessary
Weak radiation energy was able to detect.
（14C・35S・45Ca, etc.)	Comparison between soil and water culture	

32P-phosphate uptake	a rice plant	

A

soil	
water	
42 | Tomoko M. NakanishiBC― water― soil137Cs	  absorp1on	
  of	
  a	
  rice	  plant	

water	 soil	

water	soil	

3.1 Agricultural implications of Fukushima nuclear accident | 43

Development	
  of	
  
MAR	
  

5-30 µm section

1.2 µmﬁlm

nuclear emulsion ﬁlm17	
  Radioluminography(RLG)

Microautoradiography(MAR)plumule	  radicle	  Signal:	
  137Cs	  Signal:	
  137Cs	
  

100	
  µm	
  

17	

Hydrangea	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  Peach	  tree	  (1	  year	  old	
  branch)	
  Nakanishi,	
  T.	
  M.et	  al.2013,	
  Radioac.ve	
  cesium	
  deposi.on	
  on	
  rice,	  wheat,	  peach	
  tree	  and	
  soil	
  aher	
  nuclear	
  accident	
  in	
  Fukushima.	
  J	
  Radioanal	
  Nucl	  Chem	
  296,	
  985–989.	

by	
  T.	
  M.	
  Nakanishi	
44 | Tomoko M. Nakanishi

2011	
  August	

Tatata	  et	
  al.	  2012,	
  RADIOISOTOPES	
  61,	
  607–612.	
  hjp://doi.org/10.3769/radioisotopes.61.607	

300

Bq/organ250*Cs	
  concn.	
  in	
  a	
  peach	  tree	Total	
  amt.	
  of	
  Cs	
sapwood	

200
150
100

heartwood	

50
0

A

B

C

D

outer	  (bark	
  skin)	

E

F

inner	

Bq/kgDW	
 536.0	
 11.2	
 15.9	
 48.3	

*	
39.1	
 ND	

137Cs	  movement	
  in	
  tree	When	
  the	
  total	
  amt.	
  within	
  the	
  tree	  iis	
  5000	  New	
  .ssue	

5000	
 106	
Old	
  .ssue	4849	
By	
  Assistant	
  Prof.	
  D.Takada	

Soil	
  	

45	

32
56
18	

3.1 Agricultural implications of Fukushima nuclear accident | 45

Bird	
  feather	
  (Ce=a	  diphone	
  )	
  

By	
  Prof.	
  Ken	  Ishida	
  by	
  A.Prof.	
  K.	
  Ishida	

Experiment�
TMR�
１４  d�

TMR�
１４  d�

TMR�
１４  d�

TMR�
１４  d�

haylage+TMR�
１４  d�

TMR�
１４  d�

• ＴＭＲ：３５kg/d�
• haylage  ＋  TMR：
haylage１０kg  ＋  ＴＭＲ２５  kg  /d�
（total  ３５  kg）�food�
35  kg����water  80  L�

by Prof. N. Manabe
46 | Tomoko M. Nakanishi

Radioactivity  in  milk  �(Bq/kg)�

Haylage  with  137Cs�

without  137Cs
�

�0�
35�

TMR�

30�

Haylage+TMR
へイレージ+TMR�

25�
20�

haylage＋TMR：
haylage10  kg  ＋Ｔ
ＭＲ25  kg/d�

15�
10�
5�
0�
0�

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��

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Takahashi	
  et	
  al.	  2012,	
  RADIOISOTOPES	  2012,	
  61,	
  551–554. doi:10.1105/tpc.114.124628	
 by Prof. N. Manabe

3.1 Agricultural implications of Fukushima nuclear accident | 47

Circulation  of  C��
�

Prof.  N.Manabe�
Noboru	  M	anabe	  et	
  al.	

48 | Tomoko M. Nakanishi

Date	
  City	
  

Date	
  
City	
Oguni-­‐River
	
  

Area	
  15.6km²	

by	
  Prof.	
  N.	
  Ohte	

Water	  collec1ng	
  area 0.189km2	
  Rainfall	
  437mm (2012/7-­‐	  12)	
  Oﬃcial	  rainfall	
  953mm	
  (2012)	

Accumula.on	
  of	
  radioac.ve	
  Cs:	
  300000-­‐1000000	
  Bq/m2	
  

27.7Bq/m2/112days	
  →～	
  90Bq/m2/year	  Corresponds	  to	
  0.01-­‐0.03%	
  of	
  accumulated	
  
Cs（1	
  in	
  several	
  thousand)	
  
	
  
	

28	

by	
  A.	
  Prof.	
  N.	
  Ohte	
3.1 Agricultural implications of Fukushima nuclear accident | 49

Chapter 1. Overview(T.M.Nakanishi)
2. Wheat (K.Tanoi)
3. Rice breeding (K. Nemoto)	
4. Rice species (T.Fujiwara)	
5. 137Cs absorption in rice
(N.I.Kobayashi)	
6. Soil (S.Shiozawa)	
7. Low level contamination (S.Ohshita)
8. Products monitoring (N.Nihei)
9. Live stocks (N.Manabe)
10. Fish meet processing (S.Watabe)
11. Cs outflow in fish (T.Kaneko)
12. Wild birds (K.Ishida)
13. Field Decontamination(M.Mizoguchi)	
14. Fruit tree (D.Takada)	
15. Mushroom (T.Yamada)	
16. Mountain (N.Ohte)
17.Science communication (H.Hosono)	

e-­‐publish	40-­‐50	
  academic	
  staﬀs	Yamada	  et	
  al.	  2013	
  RADIOISOTOPES	  2013,	
  62,	  141–147.	
  hjp://doi.org/10.3769/radioisotopes.62.141			  	
  放射性Cs	
  
	
  	
  	
  	
  Bq/kg	  DW	
(Bq/kg乾重)	

キノコの汚染状況	
  Mushroom	
  contamina.on	

4000	
  

Cs-­‐137	  (Bq/kg)	
  

3000	
  

Cs-­‐134	  (Bq/kg)	
  

2000	
  
ND	

ND	

ND	
ND	

1000	
  
（ ）
（ ）

腐 菌
0	
  
： ：
腐 菌
生 根
菌 菌

	
  
	
  

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Hokkaido	

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明
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Chichibu(Tokyo)	

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樹芸	
 生態水文	By	  Prof.	
  T.	
  Yamada	
50 | Tomoko M. Nakanishi

100005000

Nuclear bomb test	

Fukushima accident	

2000

1000

500
200

100

50
20

10

5
2

1

0.5
0.2

0.1

0.05

Month/year	

01/2015

01/201001/2005

01/2000

01/1995

01/199001/1985

01/1980

01/1975

01/1970

01/1955

01/1965

0.02

0.01

01/1960

Cs-137
月間降下量（MBq/km2)
Monthly	
  fallout	
  
amt.	
  
of	
  137Cs	  (MBq/km2)	

monthly 137Cs fallout throughout Japan	

月／年

By A. Prof. S. Miura	(Bq)	

137Cs	
  c137
ontent	  	
  /	
  average	  Japanese	
  
man	
 man	
Average	  Cs	
  Content	
  /	
  average	  Japanese	  

3.1 Agricultural implications of Fukushima nuclear accident | 51

(Bq/l)	
137Cs	
  c137
oncn.	  in	
  urine	  of	
  junior	
  igh	
  school	
  student	
Cs	
  in	
  u
rine	
  
of	
  junior	
  high	
  shchool	  student	

hjp://www.rist.or.jp/atomica/data/pict/09/09010411/03.gif	

New educational program: effect of radiation in agriculture

Lecture + Field Study	

Conventional program	

Lectures and field studies	

What is radiation？	

Graduatel School of UT	measurement	 farm land	con	Life Sciences Industry	＋
mountain	New	
  curriculum	

52 | Tomoko M. Nakanishi

meadow	Examples of field study
Farming land :	

Iidate village

Mountain : Date City
Measurement of the tree growth
Sampling the plants, animals andwater

Field study (medow)	

3.1 Agricultural implications of Fukushima nuclear accident | 53

チューリップ

Thank	
  you	

54 | Tomoko M. Nakanishi

3.2 Studies in environmental radiology
in South-West Sweden after the Chernobyl accident
Sören Mattsson†, 1† Presenter: soren.mattsson@med.lu.se

1 Medical Radiation Physics Malmö, Lund University, Skåne University Hospital Malmö,
SE-205 02 Malmö, Sweden

The talk will shortly summarize results of some of the studies which were initiated immediately after the
Chernobyl catastrophe. The studies included investigations of radionuclide deposition, penetration in soil,transport in the food chain grass-cow-milk, and measurements of 131I and 134, 137Cs in persons. The removal of activity from hard urban surfaces was studied in sewage sludge from waste water treatment plants.
Already ongoing studies of radionuclides in brown algaes and pine needles were expanded.
It was possible to quickly launch these measurement programs because there were ongoing measurement
programs with the appropriate detectors in other ongoing research projects and an experience of sampling
and measurements in the environment since the studies of fallout from the atmospheric nuclear weapons
tests.
Some references:
S. Mattsson and R. Vesanen. Patterns of Chernobyl fallout in relation to local weather conditions. Environment. International 14, 177-180 (1988).
E. Wallström, N. Drugge, R. Vesanen, Å. Cederblad, L. Larsson, B. Arvidsson, M. Alpsten and S. Mattsson.
Radiological studies in western Sweden after the Chernobyl accident. In: The Chernobyl fallout in Sweden.
Results from a research programme on environmental radiology. Ed by L. Moberg. The Swedish Radiation
Protection Institute, Stockholm, Sweden, 1991, pp. 373-388.
S. Mattsson. B. Hemdal, E. Håkansson, L. Ahlgren, M. Alpsten, Å. Cederblad and N. Drugge. Radioactive
iodine and cesium in persons from Southern and Western Sweden after the Chernobyl accident. In: Proc.
XVth Regional Congress of IRPA, Visby, Gotland, Sweden, 10-14 September, 1989 (Ed by W. Feldt). Fachverband für Strahlenschutz e.V. FS-89-48-T, ISSN 1013-4506, pp 397-402
B. Erlandsson and S. Mattsson. Uptake of dry-deposited radionuclides in Fucus. A field study after the Chernobyl accident. J. Environ. Radioactivity 6, 271-281 (1988)
S. Mattsson and B. Erlandsson. Variations of the Cs-137 levels in Fucus from the Swedish westcoast during
a 25 year period. In: The Chernobyl fallout in Sweden. Results from a research programme on environmental radiology. Ed by L. Moberg. The Swedish Radiation Protection Institute, Stockholm, Sweden, 1991, pp.
143-149.
B. Erlandsson, B. Bjurman and S. Mattsson. Calculation of radionuclide deposition by means of measurements on sewage sludge. Water, Air and Soil Pollution 45, 329-344 (1989)
3.2 Studies in environmental radiology in South-West Sweden after the Chernobyl accident | 55

B. Erlandsson, M. Isaksson, S. Mattsson and B. Hemdal. The urban contamination after the Chernobyl accident studied in sewage water and sludge from Lund and Gothenburg. On the validity of environmental
transfer models”. In: Proceedings BIOMOVS, Swedish Radiation Protection Institute, Stockholm, Sweden,
pp 169-179, 1991 .
S. Mattsson and L. Moberg. Fallout from Chernobyl and atmospheric nuclear weapons tests. Chernobyl inperspective. In: The Chernobyl fallout in Sweden. Results from a research programme on environmental radiology. Ed by L. Moberg. The Swedish Radiation Protection Institute, Stockholm, Sweden, 1991, pp. 591-627.
P. Roos, C. Samuelsson and S. Mattsson. Cs-137 in the lichen Cladonia Stellaris before and after the Chernobyl accident. In: The Chernobyl fallout in Sweden. Results from a research programme on environmental
radiology. Ed by L. Moberg. The Swedish Radiation Protection Institute, Stockholm, Sweden, 1991, pp.
389-400.
P. Roos, E Holm, C. Thornberg, S. Mattsson. Long-term trend of 239+240Pu and 99Tc in brown algae from theSwedish west coast. In: Umweltradioaktivität - Radioökologie - Strahlenwirkungen. Band 2, Fachverband
für Strahlenschutz e.V , 1993.
R Hedvall, B Erlandsson and S Mattsson Cs-137 in fuels and ash products from biofuel plants in Sweden. J
Environ Radioactivity 31, 103-117, 1996.
CL Rääf, B Hemdal, S Mattsson. Body burden and excretion of 137Cs and 40K in subjects from the south of
Sweden. J Environ Radioactivity 47(1), 83-100, 2000.
CL Rääf, B Hemdal, S Mattsson. Ecological half-time of radiocesium from Chernobyl debris and from
nuclear weapons fallout as measured in a group of subjects from the south of Sweden. Health Physics 81,
366-78, 2001.
M Isaksson, B Erlandsson, S Mattsson. A 10-year study of the 137Cs distribution in soil and a comparison of
Cs soil inventory with precipitation-determined deposition. J Environ Radioact 55(1), 47-59, 2001.
P Lindahl, C Ellmark, T Gäfvert, S Mattsson, P Roos, E Holm, B Erlandsson. Long-term study of 99Tc in
the marine environment on the Swedish west coast. Environ Radioact 67(2), 145-156, 2003.
S. Mattsson, C. Bernhardsson and B. Erlandsson. Chernobyl influences in southwest Sweden as indicated bya colony of brown algae. Joint meeting in Radiation Biology and Radioecology Two decades after Chernobyl- summing up the consequences of the accident, Marstrand, Sweden, 25-28 April, 2006.
C. Bernhardsson, B. Erlandsson and S. Mattsson. Chernobyl influences in southwest Sweden as indicatedby needles of spruce. Joint meeting in Radiation Biology and Radioecology Two decades after Chernobyl summing up the consequences of the accident, Marstrand, Sweden, 25-28 April, 2006.

56 | Sören Mattsson

3.2 Studies in environmental radiology in South-West Sweden after the Chernobyl accident | 57

58 | Sören Mattsson

Göteborg,
20.00 April 28, 1986

Mattsson och Vesanen, 1986 (published on official Christmas card from Göteborg University 1986)

3.2 Studies in environmental radiology in South-West Sweden after the Chernobyl accident | 59

Arbetet 30 april 1986

Sydsvenskan
30 april 1986

60 | Sören Mattsson• Authorities want information• Journalists want quick answers• The public is very worried and asks questions• You want to do systematic studies to learn more

• Deposition
•
- dry
•
- wet
• Grass• Milk• Humans
Bioindicators• Sewage sludge• Brown algaes• Pine needles• Lichen (-reindeer-man)

3.2 Studies in environmental radiology in South-West Sweden after the Chernobyl accident | 61

Mattsson and Vesanen, 1988

Mattsson and Vesanen, 1988

62 | Sören Mattsson

TableDeposition in Göteborg of some γ-emitting radionuclides from Chernobyl
Radionuclide

Activity per unit area, Bq/m2

Mattsson and Vesanen, 1988
Sewage sludge

Erlandsson et al., 1991
3.2 Studies in environmental radiology in South-West Sweden after the Chernobyl accident | 63

Wallström et al., 1991

0.04-0.08 BqL-1/Bq kg-1(d.w.)
131I

0.03-0.09 BqL-1/Bq kg-1(d.w.)
137Cs

grass
milk

Wallström et al., 1991

64 | Sören Mattsson

Wallström et al., 1991

Wallström et al., 1991

3.2 Studies in environmental radiology in South-West Sweden after the Chernobyl accident | 65

Whole-body countings

Mattsson et al., 1989
Whole-body countings

Mattsson et al., 1989

66 | Sören Mattsson

Mattsson et al., 1989

Mattsson and Moberg, 1991
3.2 Studies in environmental radiology in South-West Sweden after the Chernobyl accident | 67

Fucus serratusSågtång

Fucus vesiculosusBlåstång

Marstrand
Göteborg

68 | Sören Mattsson

Mattsson and Erlandsson, 1991

Effective decrease rate related to different input sources
Atmospheric nuclar weapons tests

13 % per year – T½ = 5.5 yr

Sellafield

15 % per year – T½ = 4.6 yr

Chernobyl

8 % per year – T½ = 9.1 yr
Bomb

Chernobyl
Fucus

Sellafield

25,0

15,0

10,0

137

Cs conc. [Bq/kg]

20,0

5,0
y = 1E+109e-0,1264x
R2 = 0,99

0,0
1965

1970

1975

y = 7E+66e-0,0758x
R2 = 0,8866

y = 1E+131e-0,1512x
R2 = 0,8911

1980

1985

1990

1995

2000

2005

2010

Mattsson et al., 2006

3.2 Studies in environmental radiology in South-West Sweden after the Chernobyl accident | 69

Pine needles

Bernhardsson et al., 200670 | Sören Mattsson

Bernhardsson et al., 2006

Necessary conditions to carry out such studies• Suitable detectors in use for other projects• Staff with experiences of sampling and measurementsin the environment• Interest for such measurements
Desirable conditions• Possibilities for very early measurements• Existing background values• Fast measurement methods• National or regional coordination• National and international networks

3.2 Studies in environmental radiology in South-West Sweden after the Chernobyl accident | 71

Thank you for listening!
soren-mattsson@med.lu.se

References
Bernhardsson, C., Erlandsson, B. and Mattsson, S. Chernobyl influences in southwest Sweden as indicated by needles ofspruce. Joint meeting in Radiation Biology and Radioecology Two decades after Chernobyl - summing up theconsequences of the accident, Marstrand, Sweden, 25-28 April 2006
Erlandsson, B. and Mattsson, S.
Uptake of dry-deposited radionuclides in Fucus. A field study after the Chernobyl accident
J. Environ. Radioactivity 6, 271-281 (1988)
Erlandsson, B., Isaksson, M., Mattsson, S. and Hemdal, B.
The urban contamination after the Chernobyl accident studied in sewage water and sludge from Lund and Gothenburg.
On the validity of environmental transfer models. Proceedings BIOMOVS, Swedish Radiation Protection Institute,
Stockholm, Sweden, pp 169-179, 1991 .
Mattsson, S. and Vesanen, R.
Patterns of Chernobyl fallout in relation to local weather conditions
Enviroment. International 14, 177-180 (1988)
Mattsson, S., Hemdal, B., Håkansson, E., Ahlgren, L., Alpsten, M., Cederblad, Å. and Drugge, N. Radioactive iodine andcesium in persons from southern and western Sweden after the Chernobyl accident. In: The radioecology of natural andartificial radionuclides. Proc. XVth Regional Congres of IRPA, Visby, Sweden. Köln: Verlag TÛV Rheinland, 1989, pp 397402

Mattsson. S. and Moberg, L.
Fallout from Chernobyl and atmospheric nuclear weapons tests.
Chernobyl in perspective. In: The Chernobyl fallout in Sweden. Results from a research programme on environmental
radiology. Ed by L. Moberg. The Swedish Radiation Protection Institute, Stockholm, Sweden, 1991, pp. 591-627.

72 | Sören Mattsson

(continued)
Mattsson, S. and Erlandsson, B.
Variations of the Cs-137 levels in Fucus from the Swedish westcoast during a 25 year period.
In: The Chernobyl fallout in Sweden. Results from a research programme on environmental radiology. Ed by L.
Moberg. The Swedish Radiation Protection Institute,Stockholm, Sweden, 1991, pp. 143-149.
Mattsson, S., Bernhardsson, C. and Erlandsson, B. Chernobyl influences in southwest Sweden as indicated by acolony of brown algae. Joint meeting in Radiation Biology and Radioecology Two decades after Chernobyl summing up the consequences of the accident, Marstrand, Sweden, 25-28 April 2006
Roos, P., Samuelsson, C. and Mattsson, S.
Cs-137 in the lichen Cladonia Stellaris before and after the Chernobyl accident.
In: The Chernobyl fallout in Sweden. Results from a research programme on environmental radiology. Ed by L.
Moberg. The Swedish Radiation Protection Institute, Stockholm, Sweden, 1991, pp. 389-400.
Rääf, C.L., Hemdal, B. and Mattsson, S. Ecological half-time of radiocesium from Chernobyl debris and from
nuclear weapons fallout as measured in a group of subjects from the south of Sweden. Healt Phys . 81(4), 366-377(2001)
Wallström, E., Drugge, N., Vesanen, R., Cederblad, Å., Larsson, L., Arvidsson, B, Alpsten, M. and Mattsson, S.
Radiological studies in western Sweden after the Chernobyl accident.
In: The Chernobyl fallout in Sweden. Results from a research programme on environmental radiology. Ed by L.
Moberg. The Swedish Radiation Protection Institute, Stockholm, Sweden, 1991, pp. 373-388.

3.2 Studies in environmental radiology in South-West Sweden after the Chernobyl accident | 73

3.3 Analysis of the radiocaesium fixation process
in soil using radioactivity monitoring dataon spinach from Fukushima
Nobuko Mitsuoka†, 1, Naoto Nihei1, Sho Shiozawa1, Shuichiro Yoshida1, Kazuhiro Nishida1† Presenter: 8515242989@mail.ecc.u-tokyo.ac.jp

1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

Radiocaesium (137Cs) emitted by the Fukushima Daiichi nuclear power plant accident contaminated thesoil and agricultural products in the Fukushima area. Although 137Cs has a long half-life of 30.1 years, andshould remain in the soil surface for a relatively long time, the radiocaesium concentration in most agricultural products decreased rapidly and reached non-detectible levels within a few months. One reason forthis is thought to be the aging process, in which the binding of radiocaesium to soil particles shifted fromexchangeable weak binding to non-exchangeable strong fixation, which happened within a few months of
the accident. To determine the rate at which strong fixation occurred in Fukushima, we calculated the duration of the transfer factor (TF) using spinach produced in the Fukushima area that had been monitored forradioactivity levels. The TF is calculated as the ratio of the radiocaesium concentration of the plant (Bq/kg)
to that of the soil (Bq/kg). Since plants can only absorb the exchangeable fraction, TF represents the amountof exchangeable fraction. We obtained the radiocaesium concentrations of spinach from a published databaseof monitored radioactivity for agricultural products in Fukushima, in which radiocaesium concentration, dateof measurement, and city name were recorded, and the radiocaesium concentrations of the corresponding
soil were estimated from the city name in another published data set of soil radiocaesium concentrations.
We found that the TF of the spinach decreased exponentially with a half-life of around 15 days, and reachednon-detectible levels within around 100 days. The decrease in exchangeable radiocaesium due to strong fixation to soil particles should proceed similarly.
Keywords: Exchangeable radiocaesium, behaviour in soil, transfer factor; spinach, Fukushima Daiichi nuclear power plant accident

Fig. 1 Relationship between number of

elapsed days after nuclear fallout (Mar 20,2011) and transfer factor

74 | Nobuko Mitsuoka, Naoto Nihei, Sho Shiozawa, Shuichiro Yoshida, Kazuhiro NishidaInitial Fixation Rate ofRadiocesium to Soil Estimatedwith Municipal Monitoring
Data of Radioactivity ofSpinach in Fukushima		1

The University of Tokyo	
○Nobuko Mitsuoka、
Naoto Nihei、Sho Shiozawa、
Shuichiro Yoshida,
Kazuhiro Nishida	

BackgroundandObjective2

3.3 Analysis of the radiocaesium fixation process in soil using radioactivity monitoring data on spinach from Fukushima | 75

Fukushima Daiichi NPP Accident
As a result of Fukushima
Daiichi Nuclear Power
Plant accident (Mar 2011),
Radioactive cesium fellout and contaminated soil
and agricultural productaround Fukushima area.
Radioactivity map of area with in 80km
from Fukushima Daiichi Nuclear
Power Plant→3	

Temporal change of vegetable
Cs concentration after fallout	

ND

Percentage of highlevel contamination
sample decreased
significantly within
few months

2011
Radiocesium concentration in spinach after theaccident (2011、Fukushima、Nihei 2013 modified）

76 | Nobuko Mitsuoka, Naoto Nihei, Sho Shiozawa, Shuichiro Yoshida, Kazuhiro Nishida4Cs concentration in soil	
November 2011	

June 2011	

Estimated 	Measured 	Ø Half-life of Cs-137=30.2 years
Ø Cs concentration in soil had notdecreased within few months・・・・・(Average value of surface soil (~15cm))	

5

What happened within this few
months after the fallout??	
ØCs in vegetable decreased significantlyØSoil Cs concentration has not changed as much???
lExistence form of Cs in the soil
bioavailable form
non-bioavailable	
weak bonding	strong fixation	

Cs	

Cs	

6

3.3 Analysis of the radiocaesium fixation process in soil using radioactivity monitoring data on spinach from Fukushima | 77

Objective of Research
To estimate velocity of Cs strong
fixation to soil particle
by determining temporal change ofmunicipal level transfer factor ofspinach7

What does Cs Strong Fixation mean?
Weak bonding

Strong fixation

	• Ionic bond of cation by • Specific absorption to clay
electric charge
particle (ex. FES)
Hydrated ionsuch as Ca2+	
Swellable
Interlayer
won’t close	Cs isexchangeablewith anothercation	Cs+
Fixation	

Frayed Edge Site	

（National Institute for Agro-Environmental Sciences,
Report No.31,modified）	

78 | Nobuko Mitsuoka, Naoto Nihei, Sho Shiozawa, Shuichiro Yoshida, Kazuhiro Nishida

8What does Cs Strong Fixation mean?
Weak
弱い固定
bonding

Shift from weakbonding to strong
fixation with time

• Hardly move with soil water• Hard to absorb for plants
Cs concentration of soil	• Move along with soil
water
• Plants can easily
absorb

強い固定
Strongfixation

Strong fixation

Weak bonding	
9

Time	

Previous Research showing theevidence of strong fixation	
Ø 2-3 months after fallout
1/10-1/20 of water moleculeØ 5-6 months after fallout
1/100-1/200 of water molecule

Watermolecule	

200
cm/y	

2-3
monthslater	

10~20
cm/y	

5-6
monthslater	

Cs	

1~2
cm/y	

Transferfrom weak bonding to	strong fixation might haveproceeded during this few
months?? (Shiozawa 2013)
	

10

3.3 Analysis of the radiocaesium fixation process in soil using radioactivity monitoring data on spinach from Fukushima | 79

Objective of Research
To estimate velocity of Cs strong
fixation to soil particle
by determining temporal change ofmunicipal level transfer factor of???	
spinachChange ofTransfer Factor??	

11

What is transfer factor (TF)??
		Transfer RCs concentration in Plant (Bq/kg wet weight）	
Factor(TF) = RCs concentration in Soil(Bq/kg dry soil）	
	•Shows absorbability of Cs by plant•Transfer factor of same plants indicateslevel of fixation of Cs to soil
Objective:how fast strong fixation of Cs to soil
particle proceeded after the fallout
Estimate fixation rate through determining
decrease rate of transfer factor

80 | Nobuko Mitsuoka, Naoto Nihei, Sho Shiozawa, Shuichiro Yoshida, Kazuhiro Nishida

12

Objective of Research
To estimate velocity of Cs strong
fixation to soil particle
by determining temporal change ofmunicipal level transfer factor ofspinachChange ofTransfer Factor??	

13

Methods

14

3.3 Analysis of the radiocaesium fixation process in soil using radioactivity monitoring data on spinach from Fukushima | 81

Crop used for analysis：field-grown spinach	
Why Spinach？？
Ø Leaf vegetables are cultivated at their peak of nutrient
absorption→Directly reflect soil condition when
It cultivatedØ Seedling from harvest is relatively
http://www2.edu.ipa.go.jp
short (1-1.5months)→include samples which grown within period whenstrong fixation have not proceeded yet.
Ø Many samples are available→We need many samples to determine time variance oftransfer factor. More than 300 data available forspinach just in 2011.	

15

Calculation of Transfer Factor
	Transfer ＝ RCs concentration in Plant (Bq/kg wet weight）	
= RCs concentration in Soil(Bq/kg dry soil）	
Factor(TF)	Monitoring Data of
Agricultural Productfrom Fukushima→326 Samples of
Spinach (2011)ØCs Concentration
ØPlace of production(municipal level)ØDate of sampling

82 | Nobuko Mitsuoka, Naoto Nihei, Sho Shiozawa, Shuichiro Yoshida, Kazuhiro Nishida

16Data①：
Spinach Cs Concentration	
• Monitoring data of spinach’s Cs concentration
published on Website “Toward a new future of
Fukushima” which is operated by Fukushima
prefecture
Category

Producer
Municipality

Detected Nuclide（Bq/kg）
I-131

Cs-134

Cs-137

Sampleharvesteddate

Date ofresults
publication

Example of data on “Toward a new future of Fukushima” 	

17＜http://www.new-fukushima.jp/monitoring/ ＞visited July 8th .2015

Calculation of Transfer Factor
	Transfer ＝ RCs concentration in Plant (Bq/kg wet weight）	
= RCs concentration in Soil(Bq/kg dry soil）	
Factor(TF)	Monitoring Data ofFarmland by	
Agriculture,Forestry and
Fisheries
Research Council (AFFRC)	
ØCs concentration ofplow layer from2247 places↓	ØCalculate soil Cs
concentration of 59
municipalities	
18

3.3 Analysis of the radiocaesium fixation process in soil using radioactivity monitoring data on spinach from Fukushima | 83

Data②：Cs concentration of Farmland	
Data acquired from a report, “Radiocesium
concentration analysis” of Farmland soil
Municipalities
and section	

Common upland, land
under perennial land,
paddy field, grassland,and converted field	

Cs-134,Cs-137
and sum of Cs	

Modified datasetting Nov. 5th2011 as base date
(Bq/kg)	

Date ofPlace of Sampling	 Sampling	 Classif RCs concentration（Bq/kg）	
 Modified data setting Nov.
icationth
5 2011 as base date	of land	

Example of “Radiocesium concentration analysis”(Press released on Mar. 23rd ,2012 by AFFRC ) 	
＜http://www.s.affrc.go.jp/docs/press/120323.htm ＞visited July 8th .2015

19

Data②：Cs concentration of Farmland	Distribution map of RCs concentration of
Farmland soil (Fukushima Prefecture )•Data from 2247
spots are plotted on
the map↓•Calculate ageometric mean of
RCs concentrationof each municipality＜http://www.s.affrc.go.jp/docs/press/120323.htm ＞visited July 8th ,201520

84 | Nobuko Mitsuoka, Naoto Nihei, Sho Shiozawa, Shuichiro Yoshida, Kazuhiro Nishida

Distribution map of RCs concentration of
farmland soil in municipal level
Bq/kg

3000~
2000~3000
1000~2000
500~1000~500
Fukshima
Nuclear
Power
Plant

21

Calculation of Transfer Factor
	Transfer ＝ RCs concentration in Plant (Bq/kg wet weight）	
= RCs concentration in Soil(Bq/kg dry soil）	
Factor(TF)	Monitoring Data of
Agricultural Productfrom Fukushima→326 Samples of
Spinach (2011)ØCs Concentration
ØPlace of production(municipal level)ØDate of sampling

Monitoring Data ofFarmland by	
Agriculture,Forestry and
Fisheries
Research Council (AFFRC)	
ØCs concentration ofplow layer from2247 places↓	ØCalculate soil Cs
concentration 59
municipalities	
22

3.3 Analysis of the radiocaesium fixation process in soil using radioactivity monitoring data on spinach from Fukushima | 85

Results &Conclusion

23

ConclusionØ Estimated temporal variation of TF for theperiod 1.5-4 months after the fallout using
monitoring data of RCs concentration of
Spinach and farmland soilØ As a result, half-life of TF is estimated as
15days→TF becomes 1/100-1/200 with inaround 3.5 months after the fallout
Ø Strong fixation to soil particle proceeded withinaround 3 months after the accident which is inconsistant with previous research of Cs
24
migration rate in soil by Shiozawa et al
86 | Nobuko Mitsuoka, Naoto Nihei, Sho Shiozawa, Shuichiro Yoshida, Kazuhiro Nishida

New Research project undergoing・・・Ø This research focused on estimating overalltemporal change of TF in broad area of
Fukushima prefecture using publicized data.
Ø It does not consider the difference depending on
soil characteristics and growing environmentØ ExperimentØMeasuring temporal change of weakly bonded
radiocesium using different kind of soils from
Fukushima under different environmentØCultivating spinach with different soils from
Fukushima
25

Thank you very much!
Tack så mycket
26

3.3 Analysis of the radiocaesium fixation process in soil using radioactivity monitoring data on spinach from Fukushima | 87

3.4 Temporal change in radiocesium concentration of peaches
cultivated in Fukushima Prefecture
Kyoko Ichikawa†1, Daisuke Takata1, Mamoru Sato2, Eriko Yasunaga1† Presenter: 4170475201@mail.ecc.u-tokyo.ac.jp

1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
2 Fruit Tree Research Center, Fukushima Agricultural Technology Center, hirano, iizaka, Fukushima 960-0231, Japan

Fukushima Prefecture in Japan is well known for the production of fruits and vegetables, especially peaches(Prunus persica L.). Fruit trees are perennial plants, and most were without leaves or fruit at the time of the
Fukushima Daiichi Nuclear Power Plant accident in 2011. Over the past few years, there has been growing
concern about radiocesium contamination of peaches. Since 2012, we have measured radiocesium concentrations in peaches produced near the city of Date in Fukushima Prefecture. Although Date was exposed to highlevels of radiation, farmers have been able to produce fruits with levels of radiocesium below the minimum
acceptable. The radiocesium concentration of peaches was highest 15 days after full bloom (DAF15, DAF0
in late April). The concentration rapidly decreased until DAF60, and then slowly decreased through harvest(DAF103 in late July). This trend was consistent from 2012 to 2014.
The radiocesium concentration of peaches harvested in 2013 decreased about half to that of fruit harvested
in 2012, but the concentration in 2014 was similar to the level recorded in 2013. It seems that the transferof radiocesium from the trees to mature fruits was greatest in peaches produced in the first year after the accident, and declined in subsequent years.
Keywords: Peach fruit, radiocesium, Fukushima Daiichi nuclear power plant accident

Fig. 1 Comparison of radiocesium concentrations during fruit development stages,
from 2012 to 2014. The bars represent SE (n = 3).

(Ichikawa et al., 2015, HORT. RES. ( JAPAN) 14 (SUPPL.)

88 | Kyoko Ichikawa, Daisuke Takata, Mamoru Sato, Eriko Yasunaga

Temporal	
  Changes	
  of	
  
	
  Radiocesium	
  Concentra6on	
  of	
  Peach	  Fruits	  	
  Cul6vated	
  in	
  Fukushima	
  Prefecture	
  	○Kyoko	  Ichikawa1・Daisuke	
  Takata1・Mamoru	
  Sato2・Eriko	
  Yasunaga1		
  （1Graduate	
  School	
  of	
  Agricultural	
  and	
  Life	  Science,	
  The	
  University	
  of	
  Tokyo,	
  2	
  Fruit	  Tree	  Research	
  Center,	
  Fukushima	
  Agricultural	
  Technology	
  Center）	

Outline	  of	
  this	  presenta6on	
1. The	  reason	
  I	
  started	
  this	  study	  2. Fruit	
  cul6va6on	
  in	
  Fukushima,	
  especially	
  peach	  3. Our	  study	  	  	  “Temporal	
  Change	
  	
  of	
  137Cs	  Concentra6on	
  during	  Fruit	  Development	
  Stage	
  of	
  Peach	  	
  in	
  Fukushima	  prefecture”	
  4. Conclusion	  	
  3.4 Temporal change in radiocesium concentration of peaches cultivated in Fukushima Prefecture | 89

The	
  reason	
  I	
  started	
  this	  study	  	
2011.Mar.11	
Iidate	  villege	

Minami	  soma	  city	Japanese	  tradi9onal	
  fes9val	
  1	
  week	  ago	  before	
  the	
  earthquake	Fukushima	  prefecture	
 Fukushima	
  city	

Namie	
  	
  
town	

I  was  in  here!�

	
  	
  	
  

7km	
60km	

Fukushima	  Daiichi	  nuclear	
  power	
  plant	  Fruit	
  cul6va6on	
  in	
  Fukushima	
Fukushima	  prefecture	
  is	
  one	
  of	
  	
  
the	
  most	  famous	
  places	
  for	
  agriculture	
  in	
  Japan.	

Peach	
  produc6on	
  in	
  Japan	
Amount	  of	
  prefecture	
 produc9on	
  of	
  peach	
  (t)	

Ra9o	
  to	
  
total	
  
(%)	

1	
  

Yamanashi	

39100	

34.1	2	Fukushima	

29300	

25.5	3	

Nagano	

15400	

13.4	124700	100	

total	 Japan	Peaches’	
  	
  stock	  volume,	
  market	
  share	
  and	
  whole	  price	
  from	  2009	  to	
  2013	
  in	
  Fukushima	
  	
Year	
 Stock	  volume	
   Market	
  share	
   Whole	
  price	
  
(t)	

(%)	

(Yen/kg)	

2009	

3294	

47.5	

389	

2010	

3309	

42.2	

450	

2011	

5433	

50.9	

211	

2012	

3881	

46.3	

350	

2013	

4574	

56.0	

353	

(the	
  Ministry	
  of	
  Agriculture,	  Forestry	
  and	
  Fisheries)	
  (2014)	
  	

90 | Kyoko Ichikawa, Daisuke Takata, Mamoru Sato, Eriko Yasunaga(Tokyo	  metropolitan	
  central	
  market)	
  	
  (2013)	
  	

Our	
  study	  		  Temporal	
  Change	
  of	
  137Cs	  Concentra6on	
  during	  Fruit	  Development	
  Stages	
  of	
  Peach	
  fruits	  in	
  Fukushima	
  Prefecture.	
  

GOAL	
  	
“to	
  know	
  the	
  changing	  trend	  of	
  radiocesium	
  concentra6ons	
  of	
  peach	
  fruits”	
  	
Over	
  the	
  years	

Will	
  Cs	
  concentra6on	
  decerase?	
  	

Materials	
  and	
  Methods	
  	

Ambient	
  dose	  rate	  in	
  Fukushima	  prefecture(Aug.	
  2011,	  MEXT)	

＜Study	  site＞	
Ryozen	  Date	
  city	  A	
  commercial	
  cul6va6on	
  	
  orchard	

Fukushima	  Daiichi	  nuclear	
  power	
  plant	  3.4 Temporal change in radiocesium concentration of peaches cultivated in Fukushima Prefecture | 91

Materials	
  and	
  Methods	  	Peach(Prunus	
  persica	
  L.	
  ‘Akatsuki’)	
  3	
  trees.	
  which	
  can	
  harvest	
  about	
  100	  days	  acer	  full	  bloom	

Annual	  growth	
  in	
  Fukushima		  Jan.	
  	  	  	
  Feb.	
  	
  	
  	
  	
  Mar.	
  	
  	
  	
  	
  	
  	
  Apr.	
  	
  	
  	
  	
  	
  	
  May.	
  	
  	
  	
  	
  	
  	
  Jun.	
  	
  	
  	
  	
  	
  	
  Jul.	
  	
  	
  	
  	
  	
  	
  Aug.	
  	
  	
  	
  	
  	
  	
  Sep.	
  	
  	
  	
  	
  	
  	
  Oct.	
  	
  	
  	
  	
  	
  	
  Nov.	
  	
  	
  	
  	
  	
  
Dec.	
  	
bloom	

harvest	
Dormancy	  period	

mancy	  period	

March	
  11,	  2011	  	
  Fukushima	  Daiichi	
  nuclear	
  plant	
  Accident	

Materials	
  and	
  Methods	  	<	  Sampling	
  date>	

Full	
  bloom	
   	
  
DAF	
  0	
DAF15		  DAF30	

	  
	  Harvest	  DAF60	 DAF80	 DAF99-­‐105	
  

2012	

Apr.	
  29	

May.	
  14	
 May.	  29	 Jun.28	
 Jul.	
  17	

Aug.	
  6	

2013	

Apr.	
  18	

May.	
  2	
 May.20	
 Jun.	
  17	

n.a.	

Aug.	
  8	

2014	

Apr.	
  19	

May.	
  7	
 May.	  19	 Jul.	  18	 Jul.	
  8	

Jul.	
  29	

2015	
  

Apr.	
  17	

Apr.	
  30	
 May.	  15	 Jun.	  15	 Jul.	
  3	

Jul.	
  22	

The	
  fruits	
  at	
  DAF60	

At	
  At	
  
harvest	
harvest	dried	

92 | Kyoko Ichikawa, Daisuke Takata, Mamoru Sato, Eriko Yasunaga

Determined	
  137Cs	  and	
  40K	  by	
  germanium	
  semiconductor	
  detector.	

RESULT	  AND	  DISCUSSION	

The	
  Cs	
  changes	
  during	
  fruits	
  development	
  stage	
1000	
  

The	
  radiocesium	
  800	
  concentra6on	
  of	
  mature	
  600	
  fruit	  in	
  fresh	
  weight	
  were	  15-­‐30Bq/kg.	
  
400	
  

Cs	

2011	
  
2012	
  
2013	
  

200	
  
0	
  

0	
  
Full	
  bloom	

2014	
  

60	
  
90	
  
120	
  
DAF(days)	
  The	
  Aging	
  changes	
  of	
  radiocesium	
  concentra6on	
  and	  contents	
  of	
  fruit	  The	
  bar	  is	
  SE,	
  n=3	1500	
  
	fruits	  (Bq/kg	
  DW)	

40K	  concentra9on	
  of	
  

fruits	  (Bq/kg	
  DW)	  137Cs	  concentra9on	
  of	
  

1200	
  

1000	
  

30	
  

K	

500	
  
0	
  

0	
  
30	
  
60	
  
90	
  
Full	
  bloom	
 DAF	
  (days)	

120	
   The	  Aging	
  changes	
  of	
   K	
  concentra6on	
  of	
  fruit	  The	
  bar	  is	
  SE,	
  n=3	
	40

3.4 Temporal change in radiocesium concentration of peaches cultivated in Fukushima Prefecture | 93

CONCLUSION	
94 | Kyoko Ichikawa, Daisuke Takata, Mamoru Sato, Eriko Yasunaga

“whether	
  the	  radiocesium	
  levels	
  of	
  peach	
  will	  decrease	
  over	  the	
  years”	
1. the	  radiocesium	
  concentra6on	
  of	
  peach	  fruits	  in	
  one	
  year	  remarkably	
  declined	  by	  DAF60	
  and	  these	  values	  con6nue	
  un6l	  harvest.	
  2. The	  decrease	  of	
  radiocesium	
  in	
  peach	
  fruits	
  through	
  years	
  might	
  move	  into	  a	
  steady	
  state	
  
acer	
  3	
  or	
  4	
  years	
  from	  the	
  nuclear	
  power	  plant	
  accident.	
  We	
  would	
  check	  the	  result	
  in	
  
this	
  year	  sooner.	

Thank	
  you	  for	
  listening	

3.4 Temporal change in radiocesium concentration of peaches cultivated in Fukushima Prefecture | 95

3.5 Monitoring inspection for radiocaesiumin agricultural, livestock, forest and fishery products
in Fukushima Prefecture
Naoto Nihei†, 1, Keitaro Tanoi1, Tomoko M. Nakanishi1† Presenter: anaoto@mail.ecc.u-tokyo.ac.jp

1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

We selected and re-categorized the 90,000 items of monitoring data obtained in the 3 years following
the nuclear accident from Fukushima Prefecture focusing on the radiocaesium concentration in the following four categories of agricultural products: (A) cereals, vegetables, and fruits; (B) meats, milk, and eggs;(C) mushrooms and wild vegetables; and (D) fish in seawater and freshwater. In the case of plants grownin the field, radioactivity was high during the first 3 months after the accident because of direct fallout. The
radioactivity of foods decreased rapidly thereafter, and the radiocaesium therein seemed to be derived fromindirect contamination. However, some forestry or fish products harboured a radioactivity level greater thanthat permitted by the regulations, 100 Bq kg-1. Further selection of data from Fukushima Prefecture was performed for rice, vegetables, fruits, meats, milk, forest products, and fish, especially those produced in Sousou
district where the highest level of contamination of rice was detected in 2011. Based on the second selected
dataset, the internal exposure level of the population of the Sousou area during the first 3 months after theaccident was calculated (taking into consideration the average uptake amount of each food type) to be 0.75
mSv year-1.
Keywords: Monitoring inspection, Fukushima Daiichi nuclear power plant, radiocaesium, internal exposure

Fig.1 Measurement of radiocaesium concentration in each food item after the Fukushima DNPP accident.
(a) Category A, (b) category B, (c) category C, and (d) category D; ND: not detected. Horizontal axis indicatesdays after the accident. Vertical axis indicates the radiocaesium concentration (Bq per kg) on a logarithmic
scale.

96 | Naoto Nihei, Keitaro Tanoi, Tomoko M. Nakanishi

Sep.2,	  2015	  	

Monitoring	
  Inspec.on	
  	
  
for	
  Radiocesium	
  in	
  Agricultural,	  Livestock,	
  Forest	
  and	
  Fishery	
  Products	
  	
  
in	
  Fukushima	
  Prefecture	
  	
Naoto	
  Nihei,	
  Keitarou	
  Tanoi,	  Tomoko	
  M.	
  Nakanishi	  (	
  The	
  Univ.	
  of	  Tokyo)	
  

	
  	
  	
  Background	(μSv/h)	

Source:Ministry of Education,
Culture, Sports, Science andTechnology	

Fukushima	
  Prefecture	

Fukushima	
  Dai-­‐ichi	
  NPP	

Tokyo	
Nagoya	

3.5 Monitoring inspection for radiocaesium in agricultural, livestock, forest and fishery products in Fukushima Prefecture | 97

Fukushima	
  Prefecture’s	
  
”	

	
  	
  	
  Fukushima	
  Prefecture	
  	
  mascot	  “Main	
  Industry:	
  Agriculture	
Rice	

Cucumber	Tomato	Cs	

134Cs+137Cs	
  pollu.on	
  	

Peach	
Direct	  contamina.on	

Cs	
Cs	

	

Indirect	  contamina.on	For	
  the	  safety	  reasons,	
  Monitoring	
  is	
  
Cs	
Cs	
important.	
  Start	  from	
  17	
  
Mar.	
  2011	
  Food	
  safety	
  conﬁrma.on	
  in	
  Fukushima	
  Produc.on	  Stage	
  Distribu.on・Consump.on	  Stage	  Shops	

Product	✔	✔	Process	
  

✔	

✔	
Home	
  meals	✔	

School	  meals	✔	

Private	
  garden	Monitoring	
  inspec.ons	
98 | Naoto Nihei, Keitaro Tanoi, Tomoko M. Nakanishi

4	Monitoring	
  inspec.ons	
  

・Cut	
  a	
  sample	   ・Fill	
  the	
  sample	  to	
  pieces	to	
  a	
  vessel	
・>3	
  samples	  	
  are	
  selected	
  
・10	
  Ge	
  detectors	
  ・30	
  minutes	
  ・200	
  samples/d	

・Produc.on	
  
	
  	
  by	
  Farmer	

Number	  of	
  Monitoring	
  inspec.ons	  	
  ○ Target	
  of	
  monitoring	
  inspec.ons	  	
  • Before	
  the	
  shipment	
  and	  distribu.on	  	  Ø 500	
  items	  Ø 	  100,000	
  samples	
  (Aug.	
  2015)	
  
	
  	
  	
  
Agricultural
100,000
90,000s 80,000nio
tc 70,000eps 60,000in	
  f 50,000or 40,000eb 30,000m
u 20,000n
10,0000

Fishery
Products

Products

31%

Forest 6%
Products

.r
a
M

.y .l
a u
J
M
2011

.
p
eS

.v
o
N

.
n
aJ

38%

25%

.r
a
M

.y .l
a u
J
M
2012

Livestock
Products

.
p
eS

.v
o
N

.
n
aJ

.r
a
M

.y .l
a u
J
M
2013

.
p
eS

.v
o
N

.
n
aJ

.r
a
M

.y .l
a u
J
M
2014

.
p
eS

.v .
o n
a
N J
2015

3.5 Monitoring inspection for radiocaesium in agricultural, livestock, forest and fishery products in Fukushima Prefecture | 99

Regula.on	
  Level	  of	
  Radiocesium	
  Mar.	
  2011～Mar.	
  2012	
Item	

Bq/kg	

Vegetable,	
Cereal, Meat,
Egg, Fish, et al.	

５００	

Milk,
Dairy Product	

２００	

Water	

２００	Apr.	
  2012～	One	
  years	
  
ago	

Item	

Bq/kg	

General food	

１００	

Infant food	

５０	

Milk	

５０	

Water	

１０	

1250Bq/kg	
  in	
  Sweden	When	
  the	  radioac.vity	
  	
  of	
  the	
  sample	
  was	
  higher	  than	
  the	
  regula.on	
  level,	
  	
  
the	
  shipments	
  of	
  the	
  sampling	
  item	  are	
  stopped.	
  

7	
  

Results	
  of	
  the	  monitoring	  We	
  can	
  check	  the	
  latest	
  monitoring	
  results.	
  “hap://www.new-­‐fukushima.jp/monitoring/en/”	
100 | Naoto Nihei, Keitaro Tanoi, Tomoko M. Nakanishi

Results	
  of	
  the	  monitoring	
  
	
  
	
  

Ø Agricultural	
  Products	
  Ø Livestock	
  Products	  Ø Forestry	
  Products	  Ø Fishery	
  Products	  Ø	
  Rice	  Agricultural	
  Products	
  (Vegetable)	
  
Max	
  
84,000Bq/kg	
100000

Bq/kg

10000
1000

All	
  of	
  the	
  samples	
  are	
  under	
  
Ra.o	
  of	
  Exceeded	
  100	
  Bq/kg	
  8%	
  2013.	
100Bq/kg	
  
from	
  :A	
  1pr.	
  100・Physical	
  half-­‐life	
  (134Cs,	
  2y)	
  ・Fixa.on	
  of	
  cesium	  to	
  clay	  ・Indirect	
  contamina.on	  1ND	
3/11/11・Applica.on	  of	
  p3/11/12
otassium	
  10

3/12/13

3/13/14First	
  three	  months	
  (March	
  to	
  June)	
3.5 Monitoring inspection for radiocaesium in agricultural, livestock, forest and fishery products in Fukushima Prefecture | 101

Livestock	
  Products	
  
Max	
  
5,300Bq/kg	

10000010000

gk 1000
/
q
B 100
10
ND1

3/11/11

3/11/12

3/12/13All	
  of	
  the	
  samples	
  have	  been	  under	  100Bq/kg	
  since	  Apr.	
  2013.	

林産物
	
Max	
  
28,000Bq/kg	

3/13/14

Forestry	
  Products	
  100000(d)

10000
g 1000
k/
q
B 100
10
ND1

3/11/11

3/11/12

3/12/13

3/13/1412	
  Although	  the	  contamina.on	
  level	  has	
  gradually	
  decreased,	
  samples	
  exceeding	
  100	
  Bq/kg	  s.ll	  remain.	

102 | Naoto Nihei, Keitaro Tanoi, Tomoko M. Nakanishi

水産物

	

Fishery	
  Products	
  

Max	
  
18,700Bq/kg	
100000
10000
1000
g
k
/
q
B 100
10
ND1

3/11/11

3/11/12

3/12/13

3/13/14

Although	  the	  contamina.on	
  level	  is	
  gradually	
  decreasing,	
  samples	  exceeding	
  100Bq/kg	
  s.ll	  remain.	
13	  Fishery	
  Products	
  High Cs concentration

Mr.Fujita(Fukushima	
  Pref.)	

10,000

Close	  to	
  the	
  coastal	  area	

1,000

100

	
  Flounder		
  Fat	
  greenling	 	
  Japanese	
  sea	
  bass	

10

1
0	
  

200	
  

400	
  

600	
  

800	
  

1000	
  

1200	
  

Low Cs concentration

Wandering		
  the	
  young	
  of	
  
the	
  sardine		
  Skip	  jacks		
  Kichiji	
  rockﬁsh	Mollusk	
 Crustacean	 	
  Shellﬁsh	
Octopus		
  Shrimp	

3.5 Monitoring inspection for radiocaesium in agricultural, livestock, forest and fishery products in Fukushima Prefecture | 103

Results	
  of	
  the	  monitoring	
  
	
  
	
  

Ø Agricultural	
  Products	
  Ø Livestock	
  Products	  Ø Forestry	
  Products	  Ø Fishery	
  Products	  Ø	
  Rice	
  

Rice	
  

✔Most	
  important	
  food	  in	
  Japan!	
✔Produc.on	
  in	
  Fukushima	
  Prefecture	About	  360,000	
  tons/year	
  	
  

All	
  (12,000,000)	
  rice	  bags	
  
must	
  be	
  checked	
  from	  2012.	
 30kg	
104 | Naoto Nihei, Keitaro Tanoi, Tomoko M. Nakanishi

Inspec.on	
  of	
  all	  the	
  rice	  produced	  	
  30min/samples	
  200samples	
  /day	Much	
  .me	  is	
  needed!	
12million!	

New	
  mesurement	
  system	New	
  measurement	
  system	  (Belt	
  conveyor	
  tester)	
  米は全量全袋検査	✔	  Fast	  measurement:	
  Three	  rice	  bags	  per	  minute	
  	  ✔	  High	  sensi.vity:	
  Detect	  less	  than	
  100	
  Bq/kg	  3.5 Monitoring inspection for radiocaesium in agricultural, livestock, forest and fishery products in Fukushima Prefecture | 105

Rice	
  
100%

over	
  500	
  Bq/kg

80%
60%

86.2%	

99.9%	
 100–500	
  	
  Bq/kg

99.8%	

25–100	
  Bq/kg

40%

under	  25	  Bq/kg

20%
0%
2011

2012

2013

2014

More	
  than	
  100Bq/kg：2012 71bags/10,335,000bags	
  2013 28bags/
10,809,000bags	
  
	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  2014	
  	
  	
  	
  	
  2bags/10,956,000bags	
106 | Naoto Nihei, Keitaro Tanoi, Tomoko M. NakanishiSummary	
  
1.	
  To	
  verify	
  the	  safety,	
  monitoring	
  inspec.ons	
  have	  been	
  conducted.	
  In	
  the	
  case	  of	  	
  rice,	  all	  the	
  products	
  were	  measured	
  by	
  a	
  newly	
  developed	
  monitoring	  system.	
  
	
  
2.	
  Contamina.on	
  has	  been	
  signiﬁcantly	
  reduced	  compared	
  to	
  the	
  observed	
  levels	
  immediately	
  amer	  the	
  incident,	
  with	  the	
  excep.on	
  of	
  some	  of	
  the	
  forestry	
  and	
  ﬁshery	  products.	
  
	
  
3.	
  The	  monitoring	  system	
  must	  be	
  used	  in	
  order	  to	
  con.nue	
  producing	  safe	  agricultural	
  products.	
  Thank	
  you	
  for	
  your	  aaen.on.	

3.5 Monitoring inspection for radiocaesium in agricultural, livestock, forest and fishery products in Fukushima Prefecture | 107

3.6 Penetration of cesium, silver and other metals in soils
with examples from the Fukushima accident
Gunnar Bengtsson

Presenter: gunnarbengt@telia.com

Former Director General of SSI (Swedish Radiation Protection Institute)

Penetration of cesium, silver and other metals in soils
with examples from the Fukushima accident
Gunnar Bengtsson, PhD
Presentation at

Joint Japan Sweden Radioecology Workshop
University of Gothenburg Department of Radiation Physics
September 1-2, 2015

Metals pass through agricultural soil
About 3 mm/year• Same speed for many metals• Same speed in control soils and for organic matter• Enhanced speed at large organic amendment• Enhanced speed below the topsoil• Risk for groundwater contamination• Same speed equation applied also to Fukushimacesium and silver
108 | Gunnar Bengtsson

Do metals stay in the topsoil?
Studies on metals from organic amendments
in agriculture, e g manure, sludge• No penetration to subsoil• No metals found in subsoil• Assumptions that supplied metals accumulate, e.g.
Swedish EPA over 500 years

But yes, they do penetrate topsoil!

Evidence for penetration

Review of long term studies in agriculture• Only few studies eligible, e g with respect toexisting background levels• Penetration in topsoil standardisation with respect
to 11 parameters, e g precipitation and bulk
density, total metal, only copper and silver• 11 eligible studies result in a penetration equation
d=dt+1.9*(-0.064*pH+0.73)*s0.43*(1-s+o)0.5*(p*t)0.3*(1+0.006*p*t) /o0.5• Describing mean penetration for copper and silverin the eligible studies with standard deviation 11 %3.6 Penetration of cesium, silver and other metals in soils with examples from the Fukushima accident | 109

The penetration equation

110 | Gunnar Bengtsson

Other metals than copper and silver
Mo 1
Mn 1

Ni 1
Cr 4
Pb 4
Cs 6
Cd 9

Zn 15
All 41
0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

Relative mean penetration depth

Very large organic amendment

3.6 Penetration of cesium, silver and other metals in soils with examples from the Fukushima accident | 111

Other findings• Organic matter and control soil metals lost at
similar rates as penetration equation metal loss
• Hypothesis: If the organic matter content
increases with time, the rate of penetration
decreases, and vice versa• Of 13 cases reporting metal levels at 100-200 cm
depth, only 1 case exhibited significant
accumulation. Thus the normal case is rapid lossof metals below 100 cm; few sinks except peat

Significance of the penetration
Concern moves from organisms affected by soil toorganisms affected by groundwater

Equilibrium metal levels in groundwater after longterm sludge amendment may reach > 200 times
natural levels even with stringent restrictions.
Whether this is acceptble requires carefulassessment.

112 | Gunnar Bengtsson

Fukushima relevance• Chernobyl cesium measured depth 1-10 years,
3 locations (Rosén et al 1999) 0.89 of predicted• Fukushima cesium (Lepage et al 2014) noteligible because of extremely low bulk density
still measured depth = 0.7 of predicted• Fukushima cesium measured depth 1 year 1
location (Lepage et al 2014) 0.81 of measured
silver• Fukushima silver and cesium similar in soil andsediment (Lepage et al 2014)

Summary: Metals pass through agricultural soil

About 3 mm/year or 30 cm in a century• Same speed for many metals, hitchhiking withorganic matter• Same speed in control soils and for organic matter• Enhanced speed at large organic amendment• Enhanced speed below the topsoil• Risk for groundwater contamination• Applied also to Fukushima cesium and silver

3.6 Penetration of cesium, silver and other metals in soils with examples from the Fukushima accident | 113

Thank you!
Manuscript in advanced preparation to besubmitted for open access to Journal of
Agricultural Science
Gunnar Bengtsson:“Metals leak from tilled soil in a century –A review”

114 | Gunnar Bengtsson

3.7 Spatial and vertical distribution of fall-out 137Cs in Sweden
Mats Isaksson†, 1† Presenter: mats.isaksson@radfys.gu.se

1 Dept of Radiation Physics, Institute of Clinical Sciences,

Sahlgrenska Academy at University of Gothenburg, Sweden

Some methods used for estimating deposition density and vertical distribution of radionuclides are presented. Deposition density from nuclear weapons fallout and fallout from the Chernobyl accident has beenmodelled for an area of about 100 x 100 km2.
Using a slightly more elaborate model, the deposition density from nuclear weapons fallout has been modelled for the whole Swedish territory as well. The estimations are based on precipitation measurements andmeasurements of the activity concentration in precipitation at some reference sites.
The results from model validation indicate that the assumptions made in the model are reasonable. Furthermore, results from analysis of soil samples and field gamma spectrometry from a network of about 30
sites in Western Sweden are presented, and results from the two measurements methods are compared. The
vertical distribution is modelled by various methods, which will be discussed.

3.7 Spatial and vertical distribution of fall-out 137Cs in Sweden | 115

Spatial and vertical distribution of
fall-out 137Cs in Sweden
Joint Japan Sweden Radioecology Workshop 2 Sept.
2015, Gothenburg

Mats Isakson, prof.
Dep. of Radiation Physics

STUDIES OF SPATIAL VARIATION

116 | Mats Isaksson

Deposition density southern
Sweden2347

Deposition density
137Cs 1962-1994

1938

3717

2522

1864

1976

457

1010
2792
778

2751

4064
1560
3119
1660

2896
1050

3062

1510
1937

1264

2466

296

571
2078

1130
1200

Scale:
01020km

M. Isaksson, B. Erlandsson & M-L. Linderson, Calculation of the deposition of 137Cs from nuclear
bomb tests and from the Chernobyl accident over the province of Skåne in the southern part of
Sweden based on the precipitation. Journal of Environmental Radioactivity, 49, 2000

MethodDense network of precipitation
measurements (>100)
Quarterly measurements of activity
concentration in precipitation (1 site)
Homogeneous activity concentration in
air assumed
Kriging interpolation

3.7 Spatial and vertical distribution of fall-out 137Cs in Sweden | 117

Method
56° 30' N

1

2

3

4

8

5

2
6

Lj

56° 0' N

1
7
3

9
4
Lu

6

5

11

10

12

7
14

13

55° 30' N

8

15
16
10

Scale:

90
13° 0' E

1020km

14° 0' E

Deposition 1962-1977
56° 30' N
901

298

950

1879

1210

1258

448

56° 0' N

1418

217

2099
214

1619
387
1172
233

55° 30' N

2545

1657
127

6

335

649

374

1238

1264

976
540

210

Scale:
0

13° 0' E

2000

1750

1500

1250

1000

750

118 | Mats Isaksson

14° 0' E

1020km

Deposition 06.00 GMT May 7th
until 06.00 GMT May 8th 1986
56° 30' N

56° 0' N

55° 30' N

Scale:
0
13° 0' E

1020km

14° 0' E

4500

4000

3000

2000

1500

1000

500

100

Validation
Modelled deposition compared to• soil samples• field gamma spectrometry• AGS

3.7 Spatial and vertical distribution of fall-out 137Cs in Sweden | 119

Validation

Precipitation
62 - 77
8/5 - 31/12 -86
dep./prec.
8/5 - 31/12
-86
Air
Dep.

dep./prec.
62 - 77
Fig. 1

Old Cs-137
1962 - 77

Soil samples
Tot, Old, New+

New Cs-137
8/5 - 31/12
1986=

In situTot, Old, New

Old + New

Aerial meas.
New

9

Nuclear weapons fallout

S Almgren, E Nilsson, B
Erlandsson & M Isaksson. GIS
supported calculations of 137Cs
deposition in Sweden based on
precipitation data. Science of the
Total Environment, Vol. 368, Iss. 23, pp. 804-813, 200610

120 | Mats Isaksson

Tot Cs-137

Method – 4 reference sites

11

500
400

[Bq/m2]

Measured 137Cs deposition density

Validation

300
200
y = 0,9452x
R2 = 0,9125

100
0
0

100

200

Predicted

137

300

400

500

600

2

Cs deposition density [Bq/m ]12
3.7 Spatial and vertical distribution of fall-out 137Cs in Sweden | 121

Global fallout
S.E. Pálsson, B.J. Howard, T.D. Bergan,
J. Paatero, M. Isaksson and S.P.
Nielsen. A simple model to estimate
deposition based on a statisticalreassessment of global fallout data.
Journal of Environmental
Radioactivity, 121, pp. 75-86, 2013

Reference sites in Western
Sweden122 | Mats Isaksson

Metod• Soil sampling: 0-15 cm depth• Field gamma spectrometry• Measurements with dose rate meter
S. Almgren & M. Isaksson. Long-term investigation ofanthropogenic and naturally occurring radionuclides atreference sites in western Sweden. Journal of Environmental
Radioactivity, 100, pp. 599-604, 2009

Results
Equivalent surface activity

3.7 Spatial and vertical distribution of fall-out 137Cs in Sweden | 123

Results
Accuracy of in situ calibration

Results
Overestimation by dose rate meter(cosmic radiation excluded)

124 | Mats Isaksson

VERTICAL MIGRATION

MethodSoil sampling with corer
1
60
400cmmm

A
2

3

3.7 Spatial and vertical distribution of fall-out 137Cs in Sweden | 125

Models of vertical distribution
Convection-diffusion equation (CDE)

Relaxation depth

Chernobyl + NWF (ADE-based)
S Almgren & M
Isaksson. Verticalmigration studies of
137Cs from nuclear
weapons fallout and theChernobyl accident.
Journal ofEnvironmental
Radioactivity, 91 (1-2),
pp. 90-102, 2006.

126 | Mats Isaksson

Results
Slow vertical transport, average
depth of max activity for Cs-137:
5.4 cm
D & v consistent with other studies
In situ calibration corrected by CDE
fit with good results

Vertical migration – non-ADE
Compareprevious slide

Mats Isaksson & Bengt Erlandsson. Models for the verticalmigration of 137 Cs in the ground - a field study. Journal ofEnvironmental Radioactivity, 41, 1998.

3.7 Spatial and vertical distribution of fall-out 137Cs in Sweden | 127

Thank you!

128 | Mats Isaksson

3.8 Caesium contamination in the Swedish town Gävle
eleven years after the Chernobyl accident
and some unexpected findings
Robert R. Finck†, 1† Presenter: robert.finck@med.lu.se

1 Department of Medical Radiation Physics, ITM, Lund University, University Hospital, SE-205 02 Malmö, Sweden

The radioactive cloud from the Chernobyl accident reached the southeast part of Sweden in the morningof April 27, 1986 and continued spreading northwards. During the night between April 28 and 29 rainfallscaused increased deposition of radionuclides on the ground mainly along the Swedish coastline from thetown Gävle and northwards. The heaviest deposition occurred just north-east of Gävle, resulting in a deposition density of about 100 kBq/m2 over more than 300 square kilometres with a maximum value of up to 200
kBq/m2 over about 2 square kilometres. No specific large-scale decontamination activities of streets or land
areas were performed, other than the usual street-sweeping of non-slip sand that was spread out on streets
during winter-time and swept-up in the beginning of May. In 1997 the Swedish Radiation Protection Authority (SSI) performed mobile gamma spectrometry in the whole city of Gävle and parts of the surroundings. Hardened areas, such as asphalt covered streets in the centre of the city were found to be almost clean
from caesium deposition, but areas with one-family houses with gardens were still contaminated, although
the caesium had penetrated somewhat into the ground. Dose rates from radiocaesium in the streets in areas
with one-family houses were typically in the order of 0.02 – 0.04 µSv/h and double this value above grasscovered garden areas. The normal background in Gävle is in the order of 0.1 µSv/h, so the caesium falloutcaused a 20 – 80 % increase above the natural background in the outdoor radiation level in these areas elevenyears after the fallout. The increase in the outdoor radiation level in the centre of the city was only about 10 %.
The mobile measurements also revealed unexpected patches of caesium contamination outside of the town.
After investigation, this could be traced back to unauthorized use of non-slip sand swept from the streetsin May 1986. In one private garden, a patch of non-slip sand was found containing caesium contaminationin the order of 2 – 3 MBq/m2. This was more than ten times the maximum deposition density from direct
fallout in the area.

3.8 Caesium contamination in the Swedish town Gävle eleven years after the Chernobyl accident and some unexpected findings | 129

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

1

Caesium contamination in the Swedish city
Gävle eleven years after the Chernobyl
accident and some unexpected findings
Robert R. Finck

Department of Medical Radiation Physics, ITM,
Lund University, Malmö

Caesium contamination in the Swedish town Gävle eleven years
after the Chernobyl accident and some unexpected findings
A presentation with picture slides and comments
Robert R. Finck
Department of Medical Radiation Physics, ITM, Lund University,
University Hospital, SE-205 02 Malmö, Sweden

130 | Robert R. Finck

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

2

Dispersion modelling of the radioactive
release from the Chernobyl accident
Calculations of the atmospheric dispersion and ground depositionof the Chernobyl release made by the SMHI MATCH Modeldeveloped ten years after the accident, using European weather
observation data from the time of the accident

The radioactive cloud

The radioactive fallout on
the ground

The radioactive cloud from the Chernobyl accident reached the southeast part of
Sweden in the morning of April 27, 1986 and continued spreading northwards.
Sunday, April 27, 1986 was a beautiful day in Sweden and many were out andenjoyed the warmth of spring. No one knew then that a radioactive cloud from anuclear accident far away was spreading across the country. The cloud had reached
the islands Gotland and Oland at six o'clock in the morning and continued oversouthern Sweden. At the fixed monitoring station for gamma radiation on thesouthern tip of Öland, operated by the Swedish Radiation Protection Institute (SSI),
the pen pointer slowly started to mark an increase on a printer paper. But no one
noticed this. Somewhat later also the monitoring stations in Eksjö, Erken and Solnasilently registered the rising radiation level.
The increased radiation levels were first noticed on Monday morning, April 28, at
the Forsmark nuclear power station north of Stockholm. First it was assumed thatsomething was wrong at the power station and an alarm was sent at 10:15 to theregional county administration and to SSI. Further investigations, however, could
not find anything wrong at the Forsmark power station. At 11:30 contacts with inFinland and the Oskarshamn nuclear power station i southeast Sweden revealed
that the radioactive contamination was widespread and that the source probably
was outside Sweden.
During the afternoon, Swedish authorities tried to detect the origin of theradioactive cloud. Back trajectory calculations show that the cloud came from theregion of Latvia. At 19:00 the Soviet Union confirmed that a reactor accident had
happened in the Chernobyl reactor no 4 in Ukraine.

3.8 Caesium contamination in the Swedish town Gävle eleven years after the Chernobyl accident and some unexpected findings | 131

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

3

Simulation of the radioactive cloud from the
Chernobyl accident by the SMHI Match model

1986-04-27 00:00

1986-04-28 00:00

1986-04-29 00:00

1986-04-30 00:00

1986-05-01 00:00

1986-05-02 00:00

In 1996, the Swedish Meteorological and Hydrological Institute (SMHI) had on
behalf of SSI developed a dispersion model that could calculate the dispersion
pattern from the Chernobyl release, using weather observation data from the timeof the accident and a source term estimated by IAEA.
The picture above shows the calculated dispersion of the radioactive cloud at
midnight on the 27, 28, 29, 30 April and on 1 and 2 May 1996.
The composition of radionuclides in the air was continually monitored by highvolume air samplers at seven locations in Sweden (Ljungbyhed, Gothenburg,
Grindsjön, Stockholm, Östersund, Umeå and Kiruna). The station in Stockholm
gave the first reading, which showed the radioactive substances that were in the
Chernobyl cloud. Through analysis of the air filters information of the levels andtime-lapse of radionuclides at the seven sites was obtained. This was used toestimate the inhalation doses in Sweden.
Using air filter measurements, airborne gamma spectrometry and in situ highresolution gamma spectrometry, collective doses to the Swedish population was
calculated by Finck et al, 1988*.
* Reference: Robert Finck, Kay Edvarson, Björn Bjurman, Lars-Erik De Geer,
Ingemar Vintersved. "Collective Doses in Sweden After the Chernobyl Accident.
Calculation For Inhalation and External Irradiation." Proceedings of the seventhInternational Congress of the International Radiation protection Association, IRPA,
Radiation Protection Practice Vol III, Sydney, Australia, April 10 - 17, pp 16271630; 1988.
132 | Robert R. Finck

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

4

Simulation of the radioactive fallout from the
Chernobyl accident by the SMHI Match model

1986-04-27 00:00

1986-04-28 00:00

1986-04-29 00:00

1986-04-30 00:00

1986-05-01 00:00

1986-05-02 00:00

The picture above shows the calculated ground deposition of Cs-137 at midnighton the 27, 28, 29, 30 April and on 1 and 2 May 1996.
During the night between April 28 and 29 rainfalls caused increased deposition ofradionuclides on the ground mainly along the Swedish coastline from the town
Gävle and northwards.

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Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck5

Cs-137 from Chernobylon the ground in Sweden

Measured by
SGAB/SGU
airborne gamma
spectrometry

Calculated by SMHI Matchdispersion model using weather
observation data and a source term
estimated by IAEA

The fallout was mapped by a fixed wing aircraft carrying a 16.8 litre NaI(Tl)gamma spectrometer. The airborne mapping of Sweden was performed with eastwest flight lines generally with 50 km spacing. In the Gävle area the spacing
between flight lines was more dense. The mapping was mainly performed during
the first month after the accident. Additional mapping was performed during thesummer and autumn of 1986 and in 1987, 1988 and 1989.
The heaviest deposition occurred just north-east of Gävle, resulting in a deposition
density of about 100 kBq/m2 over more than 300 square kilometres with amaximum value of up to 200 kBq/m2 over about 2 square kilometres.
The radionuclide composition in the fallout was measured by in situ highresolution gamma spectrometry at about 70 locations all over Sweden. In
Stockholm the fallout was continuously measured by in situ high resolution
gamma spectrometry from April 28 to August 12, 1986.
The in situ measurements showed already in the first days of May that the fallout
composition varied greatly from location to location. In Stockholm, where it had
not rained, tellurium-132 (half-life 3.3 days), iodine-131 (8 days) and barium-140(12.7day) dominated initially. In the area around Gävle, where the deposition
occurred with rain, the relative deposition of Cs-134 and Cs-137 was much higher.
No specific large-scale decontamination activities of streets or land areas were
performed, other than the usual street-sweeping of non-slip sand that was spreadout on streets during winter-time and swept-up in the beginning of May.

134 | Robert R. Finck

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

6

Mobile gamma spectrometry
4 litre NaI(Tl)spectrometer andGPS-navigation

3 x 3” NaI(Tl)spectrometer inside car

Eleven years after the Chernobyl accident car-borne measurements in the Gävle
area using gamma spectrometers and GPS-navigation were performed. During themobile measurements in Gavle in May 1997, a 3x3” NaI(Tl)-crystal inside a car anda 4 litre Nal(Tl) crystal mounted on the roof of a Volvo station wagon was used .
The picture shows a later installation in 2003 in a Volvo V70, but the assembly andthe detectors were the same as 1997.
Before and after each measurement round a reference measurement at the same
location in the Regimental Park in Gävle was performed. This was to correct forvarying shielding inside the car from the gas tank and the possible change of theload in the car. The car was refuelled full before each day's measurement. With the
exception of a few sets of readings the driver was alone in the car.
The analysis system was Gammadata GDM 40 RPS 256 channels. Position
determinations were made with the built-in GPS in the GDM system. The detector
efficiency was calibrated against plates containing well-known amounts of uranium,
thorium and potassium. Calibration with respect to caesium-137 was made bycomparing the measured activity per unit area and dose rate in a well mappedreference area in the Regimental Park in Gävle.
The mobile measurements took 10 days to perform.

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Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

7

Backpack gamma spectrometer with 3”x3”
NaI(Tl)-crystal and GPS, 1997

Foto: Nils Hagberg

Foto: Nils Hagberg

The first backpack gamma spectrometry system, Gammadata GDM 40, with a 3x3
inch NaI(Tl)-crystal was used for mapping small areas of Gävle..
The GDM-system was first of its kind and specially developed for SSI. SSI bought
four units, of which one was mounted in a backpack system, one alternatively on abicycle or a pram and two used for car-borne measuring.

136 | Robert R. Finck

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck8

A mother walking in the park with herbaby in a pram ?

Foto: Nils Hagberg

Measurements in the Regiments Park in Gävle with the Gammadata GDM 40
spectrometer in a pram.

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Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

9”Under cover” gamma spectrometry
pram with 3x3” NaI(Tl) and GPS, May 1997

Foto: Nils Hagberg

Foto: Robert Finck

There is no child in the pram but a mobile gamma spectrometer with 3x3 inch
NaI(Tl)-crystal. The system made it possible to measure in places in Gävle where
it was impossible to drive a car.

138 | Robert R. Finck

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

10

High variability in ground deposition due to snow
removal activities, snow melting, runoff and rain puddles

Picture of a "hot spot” at the air force base of Söderhamn (F15) measured inAugust 1987. The white curves represent isolines with the count rate 2000, 3000,
4500 and 5000 cps measured with a portable NaI(Tl)-scintillator 20 mm above
ground. The average count rate outside the hot spot was 300 cps. In the centre of
the hot spot the count rate exceeds 5000 cps. The length of the spot is about 30 m
and the width about 5 m. A 1 m length scale is marked on the ground to the left.
The isolines have been marked with white paper tape fixed to the ground.
A possible source of the elongated hot spot could be runoff of rainwater andmelting snow. From weather records at the air force base of Söderhamn, it can beconcluded that the ground was covered with 25 cm snow at the time of deposition(rain started at 28 April 1986 16.55 local time and stopped 29 April 03.45, giving a
total of 24 mm), This was reduced to 14 cm at the end of rainfall. On the 23 April
the ground was frozen from 6 - 82 cm depth below the soil surface. On 30 April theground was thawed completely. The elongated shape of the hot spot is probably
due to tracks from snow clearance along a path to the radar equipment. In thesetracks, rainwater and meltwater have brought the radionuclides into pools of highactivity. Similar hot areas were found at other locations on the airfield. The effect
was also observed in completely undisturbed areas, which had a melting snowcover during the time of wet deposition.
Reference: Robert R. Finck. "High Resolution Field Gamma Spectrometry and its
Application to Problems in Environmental Radiology." Doctoral Dissertation,
Lund university, Department of Radiation Physics, Malmö, Sweden, ISBN 91-6280739-0; October 12, 1992.

3.8 Caesium contamination in the Swedish town Gävle eleven years after the Chernobyl accident and some unexpected findings | 139

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck11

Cs-137 on the
ground aroundGävle
mapped by
SGAB / SGU
using airborne
gamma
spectrometry

Picture showing the deposition of caesium-137 in the Gävle area, measured byairborne gamma spectrometry. Deposition values are recalculated to April 28,
1986.
Reference. H. Mellander, Airborne gammaspectrometric measurements of the fallout over Sweden after the nuclear reactor accident in Chernobyl, USSR, Swedish
Geological Co, Report TFRAP 8803, Uppsala; 1988.

140 | Robert R. Finck

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

12

External Dose rate from Cs-137 in Gävle,measured by car-borne gamma spectrometry in May 1997

Background map

The picture shows the dose rate of caesium-137 along streets and roads in Gävle
1997, measured by car-borne gamma spectrometry.
Note the low levels in the city centre and the gradually increasing levels towards
the east and northeast, which is due to the increasing ground deposition from the
Chernobyl fallout. In the northeast, there are also some "hot" spots caused bycontaminated material disseminated there.

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Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

13

External dose rate from Cs-137 in central Gävle,measured by car-borne gamma spectrometry in May 1997

0.020 - 0.025 µSv/h

0.012 - 0.018 µSv/h

0.025 - 0.035 µSv/h

0.035 - 0.045 µSv/h

In the central parts of Gävle the dose rate from Cs-137 is low. That is because thebuildings are high and all street areas are paved in asphalt and in some locations
with cobblestones. The low dose rate is (primarily) due to high buildings thatshield radiation from a distance, (secondarily) the original deposition on paved
areas was lower than on grass and (thirdly) the removal of Cs-137 from the hardsurfaces was more effective than from the grass areas.
Southwest, west and northwest of the city centre are detached houses having open
land surfaces with gardens that are often partly covered with grass. The depositionof Cs-137 has remained there and the shielding from buildings is not so dominant.
This leads to higher dose rates of Cs-137 than in the centre of the city, despite thefact that there is a gradient in the deposition of C-137 which decreases towards thewest.
In the southeast dose rates are higher, due to the combined effect of increased
deposition eastward and larger open spaces around the villas and apartmentbuildings.

142 | Robert R. Finck

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

14

External dose rate from Cs-137 in north-east Gävle,measured by car-borne gamma spectrometry in May 1997

0.050 - 0.100 µSv/h

0.025 - 0.035 µSv/h

A highlycontaminated roadwas discovered

0.012 - 0.018 µSv/h

0.035 - 0.045 µSv/h
Background map © OpenStreetMap Contributers

The deposition of Cs-137 increases towards the northeast, resulting in increased
dose rates. A "hot" spot appears along a gravel road. (See next slide)3.8 Caesium contamination in the Swedish town Gävle eleven years after the Chernobyl accident and some unexpected findings | 143

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

15

Equivalent surface deposition of Cs-137 in Gävle /Avan
measured by back-pack gamma spectrometry in June 1997
Photo view innext picture

The gravel road that has become
unknowingly contaminated withsweeping sand in May 1986
Landfill area for sweeping sand.
Sand in 1986 is buried underlayers of sand from later years
Background map © Lantmäteriverket

The contaminated gravel road was further mapped in June 1997.
Increased dose rates were measured in spots along the road, while the dose rate in
the terrain was much lower. Even at the land fill area the dose rate was lower,
which is due to several year layers of sand deposited on top of the sweeping sandfrom 1986.
Investigation revealed that at least one lorry load of sweeping sand had been laidon the gravel road and spread along the road. The sand on the road was sampled
and measured by laboratory gamma spectrometry. It contained a small amount of
Cs-134, corresponding to what should remain in Chernobyl fallout after 11 years,
proofing that the origin of the contamination indeed was Chernobyl fallout and nota lost Cs-137 source.

144 | Robert R. Finck

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

16

The gravel road at Gävle /Avan covered by sweeping sandcontaminated by Cs-137 from the Chernobyl fallout
1.5 µSv/hµSv/h
1 m above
the road,road,June 1997

Measured dose rates over the road, right here where the slope down begins.
What happened can be traced when measuring along the road and the roadside. At
least a truckload of sweeping sand from Gävle must, in May 1986, have been
tipped on the road where the down slope starts. Then a machine had pulled thesand along the road about as far as one can see in the picture. The amount of sandpulled along the road decreases towards the end of the road. The contaminatedsand is unevenly distributed in patches along the road.

3.8 Caesium contamination in the Swedish town Gävle eleven years after the Chernobyl accident and some unexpected findings | 145

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

Things are not always what
they seem to beThis idyllic summer-garden near a small lake south of
Gavle has become unknowingly contaminated with
Cs-137 from filling with sweeping sand in spring 1986

The measurement results from the road was communicated to the Gävle
municipality administration. In the late summer of 1997 the findings werementioned to the public in a radio program. After the program was broadcast, aperson contacted the Gävle municipality and said that the he/she had got atruckload of sweeping sand in spring 1986. The sand had been laid on a patio at asummer cottage. A municipality officer contacted SSI to ask for control
measurements and advice. Results from the measurements are shown in the next
slide.
The place is located about ten kilometres southeast of Gavle.

146 | Robert R. Finck

17

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

18

The most Cs-137 contaminated garden in
Sweden?

Low dose rate close to thesummer cottage

Dose rate 1.8 µSv/h just above
the grass area, 0.5 µSv/h at 1 m.
0 - 3 cm grass 16 kBq/kg
3 - 4 cm soil 17 kBq/kg
4 - 10 cm sand 15 kBq/kg~ 2 - 3 MBq/m2

This was what we found:Around the house the dose rate was low. No sand had been laid there. The sand had
been placed on a patio next to the lake at some distance from the cottage. The
deposited activity corresponded to 2-3 MBq/m2.
SSI has not recommended any action at this location because the contaminatedsurface is small and the time a person will spend there is relatively short, although
the site is used as a patio.
If the sand would have been spread around the house, then SSI would haverecommended that it should have been removed and deposited in the landfill area.
This case shows that contaminated material can take unforeseen and unfamiliar
ways to expose people.

3.8 Caesium contamination in the Swedish town Gävle eleven years after the Chernobyl accident and some unexpected findings | 147

Joint Japan Sweden Radioecology Workshop at Gothenburg University,
September 1-2, 2015
Caesium contamination in the Swedish city Gävle eleven years after the
Chernobyl accident and some unexpected findings, Robert R Finck

19

Conclusions

City of Gävle 11 years after the fallout from
Chernobyl
In the city centre, hardened areas were almost clean from Cs-137
deposition even if no measures to decontaminate had been made.
Around one-family houses with gardens, Cs-137 remained. Dose
rates were 0.02 – 0.04 µSv/h in the streets and 0.04 – 0.08 µSv/hin the gardens, i.e. 40 – 80 per cent increase above the natural
background.
Uncontrolled use of sweeping sand caused contamination of a roadand a private garden up to 2 – 3 MBq/m2, i.e. more than 10 – 20
times the fallout in the surroundings.
Several places were found to have uneven or high contamination(flooded areas, landfills with sewage sludge, ash, sweeping sandand surfaces affected by snow removal activities, etc)

Summary:
In 1997 the Swedish Radiation Protection Authority (SSI) performed mobile
gamma spectrometry in the whole city of Gävle and parts of the surroundings.
Hardened areas, such as asphalt covered streets in the centre of the city were foundto be almost clean from caesium deposition, but areas with one-family houses withgardens were still contaminated, although the caesium had penetrated somewhat
into the ground. Dose rates from radiocaesium in the streets in areas with onefamily houses were typically in the order of 0.02 – 0.04 µSv/h and double thisvalue above grass covered garden areas. The normal background in Gävle is in theorder of 0.1 µSv/h, so the caesium fallout caused a 20 – 80 % increase above thenatural background in the outdoor radiation level in these areas eleven years after
the fallout. The increase in the outdoor radiation level in the centre of the city was
only about 10 %. The mobile measurements also revealed unexpected patches of
caesium contamination outside of the town. After investigation, this could betraced back to unauthorized use of non-slip sand swept from the streets in May
1986. In one private garden, a patch of non-slip sand was found containing caesium
contamination in the order of 2 – 3 MBq/m2. This was more than ten times the
maximum deposition density from direct fallout in the area.
Final conclusion:
The experiences from measurements of the radioactive fallout in Gävle shows that
it is important to examine how the fallout occurs in the environment and to conduct
studies of this for a long time because unexpected phenomena may occur which
may lead to exposure of humans.
148 | Robert R. Finck3.9 Radio cesium fixation process to soil analyzed
by monitored radioactivity data of spinach in Fukushima
J. Mantero†, 1,2, G. Manjón1, I. Vioque1 and R. García-Tenorio1,3† Presenter: juan-mantero.cabrera@gu.se

1 Department of Applied Physics II, E.T.S.A., University of Seville, Seville, Spain

2 Department of Radiation Physics. Institute of Clinical Sciences. Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
3 Centro Nacional de Aceleradores (CNA), Seville, Spain

This work shows the magnitude and temporal evolution of the radionuclide concentrations detected in
the contaminated air masses with origin in the Fukushima accident at their arrival to Seville (Spain). In thecollected aerosol filters and during about two weeks, were detected the presence of the following radionuclides: 134Cs, 136Cs, 137Cs, 131I and 132Te (together with its short-lived daughter 132I) at minute levels and withcharacteristics 134Cs/137Cs and 136Cs/137Cs isotope ratios. The associated 131I fallout due to this episode wasalso roughly estimated from additional wet and dry deposition measurements, while the presence of 131I in
gaseous form was evaluated by collection with a pumping system equipped with a charcoal filter. All theseresults will be discussed together with the results produced at the same time by two more laboratories (Caceres and Barcelona) also belonging to the Spanish environmental monitoring network.
All samples were analyzed by low-level gamma-ray spectrometry using different types of hyper-pure germanium detectors: from P-type detectors with relative efficiencies of 30-40% and resolutions of 1.77-1.86
keV at 1.33 MeV of 60Co, to extended range (XtRa) or n-type germanium detectors with efficiencies of
37.8% and 25%, respectively. All detectors were shielded with 10 cm of old lead, and two of them were
equipped with an anticoincidence device in order to increase their sensitivity. The Radiochemical and Radioactive Analysis Laboratory at the INTE, Barcelona, and the Environmental Radioactivity Laboratory of
the University of Extremadura (LARUEX) at the Veterinary Faculty, Caceres, are accredited in accordancewith the ISO 17025 Standard. The three laboratories have participated in several national and international
intercomparison exercises involving the measurement of different environmental matrices by gamma-ray
spectrometry with very satisfactory results.
Apart from air filter measurements, the presence of 131I with origin in the Fukushima episode was detected
in several key links in the human food chain: samples of milk (goat and cow) and derivative dairy products,
as well as in various broadleaf plants. The maximum levels measured for this radionuclide were 1.11 Bq/L
in samples of milk and 1.42 Bq/kg wet weight in broadleaf plants, with obviously negligible radiologicalimplications.

3.9 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 149

J. Mantero and R. García-Tenorio

 1. The spanish environmental Monitoring

Network 2. The accident
 3. Systems at the University of Seville.
 4. Methodology & Sampling 5. Results
 6. Conclusions

150 | J. Mantero, G. Manjón, I. Vioque, R. García-TenorioThis system consists of two different networks:
1) PVRA

Environmental
monitoring network in
the vicinity of nuclear
power
plantsandfacilities of the nuclear
fuel cycle.

2) REVIRA: red densa

Environmental
monitoring
network nationwide
not associated toradioactive
facilities.

3.9 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 151

2) REVIRA: red espaciada

Environmental
monitoring
network nationwide
not associated toradioactive
facilities.

DISSEMINATION OF THE RELEASESOVER NOTHERN HEMISPHERE
Earthquake+
TsunamiExplosion of Unit 1
followed by anotherunits and venting
events during 5
more days

The cloud arrived to the IbericPeninsula by 25-26 March152 | J. Mantero, G. Manjón, I. Vioque, R. García-Tenorio

Measurement system used for γ-spectrometry
Reverse Electrode
Germanium (REGe)eXtended Range Germanium (XtRa)
Relative Efficiency
FWHM (KeV) for 1332 KeV 60Co
Ge volume (cm3 )Air Samples collectors

REGe
31,4%
1,98
130

XtRa
37,1 %
1,76
160

High Volume system~ 75000-100000 m3/week
440 x440 mm
polypropylene filters

Low Volume system~ 200-250 m3/week•aerosols onto filters with a 19.6 cm2
cellulose surface (0.8 µm, Millipore).
•gases as Iodine trapped in charcoal
cartridges.

3.9 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 153

Wet deposition sampler
Dry deposition sampler
Polyethylene collector ~500
cm2 containing distilled waterto trap aerosols.

Rainwater collector with asurface area of 1.0 m2

Quality test to the measurements (Lab 42)
For example: High volume air filters

Multi-γ emitters: 57Co, 113Sn, 88 Y, 60Co
Mono-γ emitters: 210Pb, 241Am, 137Cs, 109Cd, 139Ce, 85Sr

154 | J. Mantero, G. Manjón, I. Vioque, R. García-Tenorio•Chards•Spinachs•Goat milk
•Cow milk

European Commission
2014 Proficiency test in
137Cs air filters
Joint Research Centre
Institute for Reference Materials and Measurements

137Cs activity concentration (μBq/m3) in air samples

Cs isotopes in air filter
samples from Sevilla

350
137Cs

300
250
200

136Cs/137Cs≤0.3

150according to Ro5
European Network

100
50
0
14/03

18/03

22/03

26/03

30/03

03/04

07/04

11/04

15/04

19/04

23/04

27/04

01/05

Caceres (Spain)
Barcelona (Spain)
Braunschweig (Germany)Østerås (Norway)
Svanhovd (Norway)
Reykjavik (Iceland)

900
800

Cs-137 (uBq m-3)

700
600
500
400
300
200

17/04/11

15/04/11

11/04/11

13/04/11

09/04/11

05/04/11

07/04/11

03/04/11

01/04/11

30/03/11

28/03/11

26/03/11

24/03/11

22/03/11

18/03/11

20/03/11

100

131I (particulate) in air filter samples in Sevilla
131I activity concentration (μBq/m3) in air samples

131I (gas) in air filter samples
Date Start
Sampling
10:00 14March
10:00 21March
10:00 28March
10:00 31March
10:00 4 April
10:00 8 April

131I gas

2.000
1.800

131I

1.600

Collectiontime
7 daysVolume(m3)
250(µBq/m3)
N.D.

1.400

7 days245

2000 ± 185

800

3 days114

8310 ± 660

400

4 days156

4590 ± 380

4 days
5 days

148
182

N.D.
N.D.

1.200
1.000

600

200
0
14/03

18/03

22/03

26/03

30/03

03/04

07/04

11/04

15/04

19/04

23/04

27/04

01/05

AMD~0.5 mBq/m3
131I(gas)/131I (total) rose from0.75 to 0.9

3.9 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 155

131I Fall out
Wet-fallout

StationDate

131I (Bq/m2)

Sevilla

29 March3.30 ± 0.27

Village-60 km

3 April

2.97 ± 0.27

3 AprilDry-fallout

3.65 ± 0,38

131I
(Bq/m2)

Sevilla

26-28 March< 3.0

Sevilla

28-29 March< 2.6

Sevilla30- 1 April< 1.4

Sevilla1-3 Aprilin the food chain

2.0

Date

Station

131I

<1.8

ChardsSpinachs
Goat Milk

1.5

1.0

0.5

27
/0
3/
20
15
29
/0
3/
20
15
31
/0
3/
20
15
02
/0
4/
20
15
04
/0
4/
20
15
06
/0
4/
20
15
08
/0
4/
20
15
10
/0
4/
20
15
12
/0
4/
20
15
14
/0
4/
20
15
16
/0
4/
20
15

Less than 20Bq/m2

Bq/kg (wet weight) or Bq/L

SevillaComparison Cáceres-Barcelona-Sevilla

156 | J. Mantero, G. Manjón, I. Vioque, R. García-TenorioDetectable levels of some of the anthropogenic gamma-emitters (131I, 137Cs,
134Cs, 136Cs and 132Te) originating from the Fukushima accident were
measured in the troposphere over Spain.
 The characteristic activity ratios encountered for the contaminated plume
which reached Spain are a 134Cs/137Cs close to unity, while the 131Igaseous/ 131I
particulate ratio was greater than unity.
 The highest volumetric activity concentrations in aerosols were observed for
131I (maximum concentrations of the order of mBq/ m3), where 137Cs and 134Cs
concentrations were at least one order of magnitude lower.
 Consequently, the associated fallout had negligible radiological consequencesin Spain.
 The only radionuclide detected in key components of the trophic chain(vegetables, milk) was 131I at levels several orders of magnitude lower than the
maximum permitted levels of radioactive contamination of foodstuffs andfeedstuffs following a nuclear accident in Europe.


3.9 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 157

3.10 Radioecology competence needs at radiation accidents– the case of the Chernobyl accident management in Sweden
Gunnar Bengtsson

Presenter: gunnarbengt@telia.com

Former Director General of SSI (Swedish Radiation Protection Institute)Radioecology competence needs at radiation accidents –the case of the Chernobyl accident management in Sweden

Who will pay for never used competence?
• Authority tasks at the Chernobyl accident• Rare recurrence of radiation accidents• Authority competence needs• Meeting the needs - ideally• The second best approach• Summing up
158 | Gunnar Bengtsson

Swedish radiation protection authority
29 years ago April-May 1986

Pandemonium (all devils loose..)• 100 000 phone calls in a week
• Daily press conferences• All at once
– Coordinate 700 persons across the country– Assess risks today and after a year
– Provide bases for decisions to government,
authorities, businesses and the public– Initiate long term evaluation

Provide guidance for politicians

3.10 Radioecology competence needs at radiation accidents – the case of the Chernobyl accident management in Sweden | 159

Accidents
occur
rarelyCompetence that is rarely used
Example of a research environment• Formation of an organisation• Use over a couple of decades• Reorganisation or replacement to meet tasks that are
more on the current agenda• Researchers move to other job or areas of interest, or
retire160 | Gunnar Bengtsson

Main competence: dangerous or not?

Authority competence needs
People with knowledge who can• Cooperate very broadly• Dialogue with authority on risk assessment andprojections• Quickly be available for action and act• Use their international network• Discuss with media and the public to increasecredibility of authority communication

3.10 Radioecology competence needs at radiation accidents – the case of the Chernobyl accident management in Sweden | 161

Options for providing competence

Meeting the needs
Ideal• Environments where knowledge can develop• People who can contribute in crisis• …. and practise inbetween

Million dollar question
Who will pay for something that is hardly ever used?

162 | Gunnar Bengtsson

Supporting the authority
Second best
• Critical mass at institution with appropriatecompetence, that can be made available• Synergi with other emergency preparedness• Stand-by’s: left the field but could be reassigned• Apps for knowledge, e g becquerel budgets• Networks with interested parties, e g civil defence,social media• Plans for quick training of broader groups• ….

Summary• Unreasonable expectations on authority• Decades between needs• Define and prioritize tasks and maintainminimal competence• Prepare to support competence further
down the competence pyramid

3.10 Radioecology competence needs at radiation accidents – the case of the Chernobyl accident management in Sweden | 163

3.11 Application of the in-growth core method
to investigate caesium absorption in tree rootsin a northern forest in Fukushima
Osamu Hashimoto†, 1† Presenter: o.hashimoto@fr.a.u-tokyo.ac.jp
1 Graduate School of forest science, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

Significant quantities of radioactive caesium (137Cs) were deposited in forests after the Fukushima Dai-ichi
nuclear power plant disaster of March 2011. To measure the translocation of 137Cs from soil to tree roots, weapplied the in-growth core method generally used to measure the biomass of roots, and examined the efficiency of this process. The study area was a Japanese cedar plantation in Date city, Fukushima Prefecture. The
in-growth core method was applied to two different types of soils, one containing 137Cs (+Cs) and the otherwith no 137Cs (–Cs). Ten cylindrical cores 5 cm in diameter were buried in the forest floor containing +Cs or–
Cs soils with no roots for a period of 1 yr (12 June 2013–11 June 2014). On 11 June 2014, the fine roots wereseparated from the soils at 0–3 cm, 3–10 cm, and 10–20 cm to measure radioactivity. At each depth, there
were significant differences in the average soil 137Cs concentrations between +Cs and –Cs. The average 137Csconcentration of the +Cs soil was at least three-fold higher than that of –Cs. There was a positive correlation
between the 137Cs concentrations of the soils and that of tree roots (Figure 1). Our results indicate that thetree roots absorbed 137Cs mainly from the soil and that if the soil 137Cs concentrations had been controlled,
this would have reduced the 137Cs in the tree roots.
Keywords: Radiocaesium; tree roots; Fukushima Daiichi nuclear power plant accident;
in-growth core method

Fig. 1 Relationship between 137Cs concentrations of soils and tree roots

164 | Osamu Hashimoto

Applica'on	
  of	
  the	
  in-­‐growth	
  core	  method:	  understanding	
  cesium	
  absorp'on	  	
  through	  tree	  roots	
  in	
  Fukushima	
  forest	  	

University	
  of	
  Tokyo	  Osamu	  Hashimoto	The	
  accident	
  	
  of	
  Fukushima	
  dai-­‐ichi	
  nuclear	
  power	
  plant	  	
  	

Forest	  covered	
  71%	  of	
  polluted	  land	  area(Ohta,2011)	  		  	
  Occurred	
  in	
  11,	
  March	  2011	
  	
  Released	  radioac've	
  materials	
  Noble	
  gas 500PBq	
  Radioac've	
  Cesium(134Cs,	
  137Cs)	
  20PBq	  Radioac've	
  Iodine 500PBq	
  (PBq=1015Bq)(TEPCO	
  2012	
  )	
  
	
  
	
  Half-­‐life	
  
131I	
  	
  8.1	  days	  134Cs	  	
  2.06	
  years	
  137Cs	  	
  30.2	
  years	  3.11 Application of the in-growth core method to investigate caesium absorption in tree roots in a northern forest in Fukushima | 165

Two	
  pathways	
  of	
  Cs	
  absorp'on	  	
  Branches	
  and	
  leaves	  	
  1.98kBq	  m-­‐2	
	
  
	
  

Stem	
  
3.69kBq	  m-­‐2	？	

The	
  amount	
  of	
  transloca'on	
  is	
  
s'll	
  unknown.	

Through	
  
bark	

	
  
	
  
	
  

soil	
  	
  50-­‐60kBq	
  m-­‐2		  The	
  radioac've	
  cesium	
  concentra'on	  Through	  	
  at	
  Kashiwa,	
  Chiba	  prefecture	
  
tree	
   	
  
	
  	
  	
  	
  	
  	
  	
  roots	
	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  (	
  	
  K.	
  
	
  	
  	
  	
  	
  	
	
  Fukuda	
  et	
  al,2013)	

Barriers	
  of	
  research	
  techniques	
  	
  
in	
  root	  studies	
	
  
	
  

・Diﬃculty	
  in	
  observing	
  temporal	
  change	
  of	
  accumula'on	
  in	
  root.	
  ・Diﬃculty	
  in	
  es'ma'ng	
  growing	
  period.	
  ・Diﬃculty	
  in	
  tracing	
  an	
  individual	  a^er	  sampling.	
  	
  Studies	
  on	
  the	
  rela'onship	
  of	
  roots	
  in	
  forest	
  and	
  radioac've	
  Cs	
  are	
  limited.	
  To	
  inves'gate	
  the	
  rela'onship	
  of	
  radioac've	
  Cs	
  and	
  roots	
  in	
  forest,	
  	
  	
  the	
  method	  to	
  solve	
  these	  diﬃculty	
  is	
  needed.	

166 | Osamu Hashimoto

What	  is	
  in-­‐growth	
  core	  method?	
Advantages	
Experiment	
  in	
  forest	
Bury	
  the	
  core	

Pick	
  up	
  the	
  cores	
  and	
  separate	
  the	
  roots	
  from	
  
soil	
  	

Can	
  es'mate	
  the	  growing	  period	
  of	
  roots	  	Don’t	  include	
  roots	  	  	1	  year	

Separated	
  soil	  and	  roots	  	

Growing	
  period	
  is	
  
for	
  1year	

Date	
  1	

This	
  is	
  a	
  classical	
  method	

Date	
  2	

Applica'on	
  of	
  in-­‐growth	
  core	  method	  	Transloca'on	
Fixed	
  amount	+Cs	

-­‐Cs	Use	
  two	
  diﬀerent	
  types	  of	
  soils	
  (+Cs,-­‐Cs)	
  	
  ・+Cs	  contains	
  radioac've	
  cesium	  	
  ・-­‐Cs	
  doesn’t	
  contain	  radioac've	
  cesium	  Both	
  soils	
  buried	
  in	
  same	  contaminated	
  forest	  Es'mate	  the	
  amount	
  of	
  transloca'on	
  and	
  absorp'on	
  of	
  radioac've	
  cesium	  by	
  the	
  diﬀerences	
  of	
  concentra'on	
  in	
  roots	  	
  3.11 Application of the in-growth core method to investigate caesium absorption in tree roots in a northern forest in Fukushima | 167

Hypothesis	
+Cs	
 -Cs	

	

Absorption	
 Translocation	

Hypothesis 1	
 ++	

+	

→	

Yes	

Yes	

Hypothesis 2	
 +	

+	

→	

No	

Yes	

Hypothesis 3	
 +	

-­‐	

→	

Yes	

No	

1.	
  

2.	

3.	

Study	
  site	  	The	
  air	
  dose	  rate	  (Ministry	
  of	
  educa'on	
  2013.11.19）	
  	

168 | Osamu Hashimoto

Study	
  site：	
  Upper	  part	  of	  	
  the	
  Kami-­‐Oguni	  River	  headwater	
  catchment.	
  	
  50km	  northwest	
  of	
  FDNPP.	
  Eleva'on:	
  350m	
  
	
  
	
  
	
  
Vegeta'on：Cedar	
  planta'on	
  	
  
Age:	
  About	
  50	
  years	
  DBH:	
  Around	
  25cm	  Height:	
  Around	
  30m	  Stand	
  density:	
  2100/ha	  	
  Method	
  soils	
  and	
  mesh	  bags	  	
	  Soils	  +Cs:	
  Collected	
  from	  study	  site(Day	  of	
  collec'on：2013.6.12)	
  -­‐Cs:	
  Collected	
  from	  cedar	
  planta'on	
  in	
  Nantan	
  city,	  Kyoto	
  	
  
	
  	
  	
  	
  	
  	
  	
  	
  prefecture(500km	
  southwest	
  )	
  
	
  Mesh	  bag	
  Length:	
  20cm	  	
  Diameter:	
  5cm	  	
  mesh	  size:	
  4mm	  	  
	  (picture)	
  Mesh	  bag	
10	  mesh	  bags	
  were	  buried	
  for	
  each	  soils.	
  	
  
	
  
Buried	  period：12	
  June	  ~	
  11	
  June	  2014	  Soils	
  for	
  +Cs	
  and	  -­‐Cs	
  were	  collected	
  separately	
  at	
  0-­‐10cm	
  and	
  10-­‐20cm	
  in	
  depth,	
  then	
  buried	
  at	
  the	
  same	  depth.	
  Measurement	
  of	
  Cs	
  concentra'ons	Collect	
  Divide	  mesh	
  bags	 three	  layer	  	
  0-­‐3cm	

Separated	

Measure	  Cs	
  concentra'ons	

soils	

	  NaI	
  Gamma	  Counter	  	

roots	High	
  purity	  germanium	
  detector(Ge)	

3-­‐10cm	

10-­‐20cm	

・Roots	
  were	  washed	
  twice	
  on	
  the	
  pul	
  ・Roots	
  were	  measured	
  by	
  germanium	
  detector	  	  	
  Soils	
  were	  measured	
  by	
  NaI	
  Gamma	  Counter	
  	
  
	
  

3.11 Application of the in-growth core method to investigate caesium absorption in tree roots in a northern forest in Fukushima | 169

Radioac've	
  Cs	
  concentra'on	
  	
  
in	
  soils	
  of	
  study	  site	Concentra)on	
  of	
  137Cs	
1	
  	
  

10	
  	
  

100	
  	
  

1000	
  	
  

10000	  	
  100000	
  	
  

F,H	
F,H:	
  Liler	
  
	
  
A1	
  A2:	
  Soil	  	

A1	

Average	
  thickness	
  

A2	

	
  ・	
  The	  concentra'on	
  of	
  137Cs	
  was	
  exponen'ally	
  decreased	
  

	
  	
  	
  	
  F,H:	
  3.3cm	
  	
  
	
  	
  	
  	
  A1:	
  4.8cm	
  	
  
	
  	
  	
  	
  A2:	
  11.2cm	

The	
  137Cs	  concentra'on	
  of	
  	
  
soils	  in	
  mesh	  bags	
0	
  	
  

1000	
  	
  

Concentra)on	
  of	
  137Cs	

2000	
  	
  

3000	
  	
  

4000	
  	
  

5000	
  	
  

6000	
  	
  

0-­‐3cm	  3-­‐10cm	
  10-­‐20cm	
  

+Cs	
  
-­‐Cs	
  ・There	  was	
  signiﬁcant	
  diﬀerence	
  between	
  +Cs	
  and	
  –Cs	
  at	
  
each	
  depth	  (p=0.05)	
  ・Radioac've	
  	
  Cs	
  Contaminated	
  -­‐Cs	  170 | Osamu Hashimoto

7000	
  	
  

Roots	
  in	
  mesh	  bags	
0	
  

20	
  

40	
  

137Cs	  in	
  the	
  roots	
  137Cs	  concentra'on	
  	
  	
  

Dry	
  weight(g	
  m-­‐2)	
60	
  

(Bq	
  kg-­‐1)	
0	
  	
  

5000	
  	
  

(Bq	
  m-­‐2)	

10000	  	
  0	
   10000	
  20000	
  30000	
  Bq	
  kg-­‐1	Bq	
  m-­‐2	

0-­‐3cm	  0-­‐3cm	  0-­‐3cm	  3-­‐10cm	
  3-­‐10cm	
  3-­‐10cm	
  10-­‐20cm	
  -­‐Cs	
  

+Cs	
  

+Cs	
  

+Cs	
  
10-­‐20cm	
  -­‐Cs	  -­‐Cs	
  10-­‐20cm	
  ・Detected	
  about	
  137Cs	
  ・Ten	
  mesh	  bags	
  were	  summarized	
  in	
  one	  at	
  10-­‐20cm	
  of	
  –Cs	  	
  ・Ten	
  mesh	  bags	
  were	  summarized	
  in	
  three	
  at	
  others	
  	
  	
  
・The	
  amount	
  of	
  +Cs’	
  137Cs	
  	
  2	
  to	
  20	
  'mes	  than	
  –Cs’	

137Cs	  concentra)on	
  of	
  roots	
  (Bq	
  kg-­‐1)	

Rela'onship	
  of	
  soils	
  and	
  roots		
  Absorp'on	
  coeﬃcient	

14000	  	
  12000	
  	
  

y	
  =	
  1.41x	
  +	
  48.6	
  R²	
  =	
  0.679	

10000	  	
  Transloca'on	

8000	
  	
  
6000	
  	
  
+Cs	
  

4000	
  	
  

-­‐Cs	
  

2000	
  	
  
0	
  	
  

0	
  	
  

1000	
  	
   2000	
  	
   3000	
  	
   4000	
  	
   5000	
  	
   6000	
  	
   7000	  	
  137Cs	  concentra)on	
  of	
  soils	
  (Bq	
  kg-­‐1)	

・Rela'onship	
  between	
  soils	
  and	
  roots	
  was	
  propor'onal	
  ・There	  was	  a	
  high	  correla'on	
  between	
  roots	
  and	
  soils	
  ・The	
  137Cs	  concentra'on	
  of	
  roots	
  were	  more	  than	
  the	
  137Cs	  concentra'on	
  of	
  soils	  3.11 Application of the in-growth core method to investigate caesium absorption in tree roots in a northern forest in Fukushima | 171

Cs	
  accumula'on	
  path	  to	
  tree	  root	+Cs	
 -Cs	
Hypothesis 1	
 ++	

+	

	
→	

Absorption 	
 Translocation	
yes	

yes	

Absorp'on＞Transloca'on	
1.	
  ・Roots	  emerged	
  in	
  ‘-­‐Cs’	
  were	  contaminated	
  
by	
  Cs	
  
・The	
  amount	
  of	
  absorp'on	
  was	  	
  much	  larger	  than	
  the	
  amount	
  of	
  transloca'on	

Summary	
Applying	
  the	
  in-­‐growth	
  core	  method	  was	
  supposed	
  to	
  
have	
  revealed	
  the	
  ﬁndings	
  below:	
  	
  ・Rela'onship	
  between	
  soils	
  and	
  roots	
  was	
  propor'onal	  →There	  was	  a	
  high	  correla'on	
  about	
  Cs	
  between	
  
	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  roots	
  and	
  soils	
  	
  
・The	
  amount	
  of	
  absorp'on	
  were	  	
  much	  larger	
  than	
  the	
  amount	  of	  transloca'on	
  	
  →The	  accumula'on	
  pathway	
  was	
  mainly	
  absorp'on	

172 | Osamu Hashimoto3.12 Spatiotemporal variation of radiocaesiumon the forestfloor in mixed deciduous forests
in Fukushima, Japan
Momo Takada†,1, Toshihiro Yamada1, Toshinori Okuda1† Presenter: taka-momo@hiroshima-u.ac.jp

1 Graduate School of Integrated Arts and Sciences, Hiroshima University,
1-7-1, Kagamiyama, Higashi-hiroshima, Hiroshima 739-8521, Japan

Radioactive fallout from the Fukushima nuclear power plant accident remains in the neighbouring forests, where large amounts of radiocaesium were deposited on the forest floor. To understand the dynamics
of radiocaesium within a forest community and its outflow from the forest to other ecosystems, the spatiotemporal variation of radiocaesium on the forest floors needs to be clarified. This study examined the spatial
distribution of radiocaesium on a forest floor and the downward migration of radiocaesium in the forest soil.
Field surveys were conducted in Fukushima Prefecture from July 2013 to November 2014. Study sites wereplaced in six mixed deciduous forests dominated by Quercus crispula and Abies firma. There was marked spatial heterogeneity of the radiocaesium distribution on the forest floor. The activity of radiocaesium in the soil
decreased with increasing distance from trees, while it increased with tree size around the bases of deciduous
broadleaf trees. This pattern is thought to be affected by throughfall and stemflow containing radiocaesium.
Radiocaesium migration from the litter layer to the soil layer was observed. During our study, the activity ofradiocaesium in the litter layer decreased by 90%, while the activity in the soil layer increased. At all study
sites, the migration rates from the litter layer to the soil layer were much larger than those within the soil
layer, suggesting that most radiocaesium persists near the soil surface.

Keywords: Spatial heterogeneity, vertical distribution, radiocaesium migration

3.12 Spatiotemporal variation of radiocaesium on the forestfloor in mixed deciduous forests in Fukushima, Japan | 173

3.13 Predicting the future radiocesium distribution
in Fukushima from the distribution of global fallout
in forested areas in Japan
Satoru Miura†, 1† Presenter: a-miura@mail.ecc.u-tokyo.ac.jp

1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657 Japan

Forests are thought to retain 137Cs for long periods. Whether this is true for 137Cs fallout in forest areasfrom the accident at Fukushima Dai-ichi nuclear power plant (FDNPP) is an issue of major concern forthe people of Fukushima and its surrounding areas. To answer this question, we investigated soil samples
that had been systematically collected from 316 forest sites in Japan just before the accident, These samples
contained a signal from the global 137Cs fallout (137Cs-GFO) derived from above ground nuclear weapons
tests during the 1950s and 60s. The radioactivity levels due to 137Cs-GFO in the three layers of soil samples(0–5, 5–15 and 15–30 cm in depth) at each site were measured. The 316 sampling sites throughout Japan
were divided into 10 areas, and the effects of rainfall and geomorphology on 137Cs-GFO inventories were
tested. In addition to the analysis of 137Cs-GFO, the behaviour of 137Cs emitted from FDNPP (137Cs-Fk)
within a whole tree was examined to determine the effects of biological processes on 137Cs transport fromtrees to soils. The radioactivity due to 137Cs-Fk in the above- and below-ground parts of three 26 yearold Quercus serrata trees and the associated soils in a contaminated area of Fukushima was determined.
The average 137Cs-GFO inventory of forest soils in Japan was 1.7 kBq m–2 as of 2008. Reported 137CsGFO inventories vary substantially (0–7.9 kBq m–2) across the country. There is a large accumulation of137
Cs-GFO in the north-western part of the country, facing the Sea of Japan. Winter rainfall has influenced this high accumulation of 137Cs-GFO. The vertical distribution of 137Cs-GFO indicates that 44% of
137
Cs-GFO has remained within the top 5 cm of the soil profiles, whereas the remaining 56% was foundin layers at depths of 5–30 cm, indicating that a considerable downward migration of 137Cs-GFO has occurred in forest soils in the past fifty years in Japan. However, multiple linear regression analysis of geomorphological factors related to soil erosion, such as the inclination angle or catchment area calculated
from a Digital Elevation Model, revealed almost no significant effects on the distribution of 137Cs-GFO.
The radioactivity due to 137Cs-Fk in the fine roots collected from the 0–10 cm layer was 1600–2400 Bq/
kg, which was comparable to the levels in one-year old branches (1400–2200 Bq/kg). The radioactivity inthe fine roots was seven times higher than in the soil of the 50–100 cm layer (220–350 Bq/kg). This difference in the radioactivity of the fine roots among the soil layers was remarkably small when compared withthe difference of 1000 times or more in the radioactivity of the soil in the same layers (one outlier sample inthe 40–60 cm layer was excluded). The findings indicated that 137Cs-Fk had circulated throughout the whole
tree within three years of the accident. Considering that root litter was retained inside the soil, we estimatedthat 137Cs contamination on the above-ground parts of trees could be transported to soils through the roots.
Most of the 137Cs-GFO deposited fifty years ago has remained in the sites where it was deposited and has
gradually migrated downward in the soil. There are two possible major driving forces that could explain the
downward migration of 137Cs-GFO. One is the migration of 137Cs associated with vertical water movement
and the other is the transportation of 137Cs by root litter or root exudates. Further research is required toanalyse these processes and obtain reliable predictions of the future distribution of 137Cs-Fk.
Keywords: Radioactive contamination, Fukushima Dai-ichi nuclear power plant, forest soil, trees, secondary migration

174 | Satoru Miura

Workshop in Sweden
2-Sep-2015

Predicting the future radiocesium distribution
in Fukushima from the global fallout
distribution in forest area in Japan

Satoru Miura
University of Tokyo



Background

As of May 31, 2012

137Cs

14-17 PBq
10-20% 80-90%
Ocean• Fallout in forests – people
concern the whereabouts.
• Japan – tectonic active,
steep land,high precipitation.
• 137Cs emitted by nuclear
weapon test (global fallout)– a tracer of soil erosion.



3.13 Predicting the future radiocesium distribution in Fukushima from the distribution of global fallout in forested areas in Japan | 175

Monthly fallout of 137Cs in Japan, 1957-2014
100-2Monthly Cs-137 fallout (kBq m )101

Fukushima

50 years
Nuclear weapon test

Chernobyl

0.1

Sampling period
2006 – 2010

0.01
0.001
0.00010.00001
0.000001
60.1.170.1.180.1.190.1.100.1.110.1.1

Date
Created from data of Environmental radiation database (Nuclear Regulation Authority. http://search.kankyo-hoshano.go.jp/servlet/search.top)

Objectives
1.

A nationwide distribution of global fallout (137Cs-GFO)
50 years after deposition.

2.

What is the major process for the secondary migration?

176 | Satoru MiuraMaterials and method•	  4	
  sub-­‐plots	  	
  per	
  site	  •	
  316 sites – 1 site / 800 km2
in 2006–201045•	
  Analyzed for NW1
10 sub-areas	  SE1

0.1 ha45°40

35.7 m

NW2

40°

SE2
NW3

• Mineral soils of 3 layers per pit
0 – 5 cm
– 15
– 30

NW4
35

35°

SE3
SE4

NW5
30





SE5

30°

135°

140°

145°

130°

130

135 

140

3470
samples

145Radioactivity determination•	  Measured	
  samples	
  in	
  20	
  mL	
  vial	  	
  by	
  NaI	
  gamma	  	
  counter	
  in	
  30	
  min.	
  •	
  Veriﬁed	
  60	
  samples	
  with	  	
  Ge	  detector	
  measurements.	
  
300

2

NaI (Bq/kg)

R = 0.98
200
100
0
0

100 200
Ge (Bq/kg)

300

•	
  Cs	
  accumula@on	
  in	
  each	  soil	  layer(i):	
  	
  Cs_invi	
  =	
  Cs_conci	
  (mi	
  wci	  (1	  –	
  Gri/100))	
  

3.13 Predicting the future radiocesium distribution in Fukushima from the distribution of global fallout in forested areas in Japan | 177

137Cs-GFO accumulation in soil (0–30 cm)

1.7 kBq m-2

Forest soils in 2008 (this study)

1.5 – 4.0 kBq m-2+

Global fallout measurement
at 7 observatories by 1970
(decay-corrected as of 2008)



2000
1500

8

500

0

0

2

0

1000

2000

3000

Summer rainfall, Mar–Sep(mm)

178 | Satoru Miura

-2

1000

6
4

Cs-137 (kBq m )Winter rainfall, Oct–Feb (mm)

Effect of seasonal rainfall on accumulation
Effect of winter rainfall
was significant.

Effects of landform and vegetation was weak
Mul$-­‐regression	
  analysis	
  Landform	
  factors	
  :	
  eleva$on,	
  azimuth	
  from	  south,	
  slope	
  inclina$on,	
  topographic	
  wetness	
  index,	
  others	  Vegeta$ve	
  factors	
  :	
  stand	
  age,	
  stand	  volume,	
  shrub	
  layer,	  understory	
  layer	  Country

SE1

NW3

SE4

R square adjusted

0.00

0.27

0.16

Root mean square error

1.4

0.7

1.7

0.7

0.431

0.004

0.039

<.001

306

40

39

52

Elevation

0.196

0.001

0.007

0.075

Azimuth from south
Slope inclination

0.734
0.274

0.808
0.579

0.702
0.107

<.001
0.017

p-value (Prob>F) for whole model
Observation (N)0.27

p-value (Prob>|t|) for parameters	
  :	
  signiﬁcantVertical distribution of 137Cs in soil
5 cm downward during the past 50 years.



3.13 Predicting the future radiocesium distribution in Fukushima from the distribution of global fallout in forested areas in Japan | 179

Summary• 1.7 kBq m-2 of 137Cs - consistent with measurements.
• 137Cs has remained in the forests for 50 years.
• 5 cm vertically downward migration of 137Cs in soil.

Secondary migration processes
1.

Erosion on slope

2.

Physical migration in soil

3.

Bioturbation by soil animals

4.

Bioturbation by tree rootsMaterials and methodStudy site: Miyakoji, Fukushima
20 km west from FDNPP
137Cs, 100–300 kBq/m2(July 2011)
3 deciduous oak trees(Quercus serrata)
in Mar–Apr 2014
, 5 parts of aboveground, 4 parts of belowground< 1 yearbranch>6m, Litter-LF, H layers> 4 m trunk, Soil-0–5 , –10, –15, –20,
–40, –60, –80, –100cm>2m,Fine & medium roots along depth, Determined 134Cs, 137Cs activity(decay-corrected at 1 Apr 2014)

Core of stump
Co > 10 mm
Fi < 2 mm

180 | Satoru Miura

LF horizon

H horizon
0–5 cm–10 cm–15 cm–20 cm

> 0.5 mMe 2–10 mm

12

Soil

–40 cm–60 cm–80 cm–100 cm

Aboveground analysis 

Heavy machine &hand pick

Belowground analysis
Core of stump

Root washing 

Small
<2mm

Medium Large
2-10mm >10mm

3.13 Predicting the future radiocesium distribution in Fukushima from the distribution of global fallout in forested areas in Japan | 181

Litter and soil analysis, fine and medium roots
Soil
LF horizon
H horizon
0–5 cm–10 cm–15 cm–20 cm–40 cmFine &
medium roots
0–10 cm deep

20–40 cm deep

–60 cm–80 cm< 50 cm deep–100 cm 

137Cs 137
conc.
Cs conc.
in trees
in of
trees
above/below-groundand in soils
137Cs went

round thru
the whole trees
within 3 years 

182 | Satoru Miura(N=3, Mean ± SD)

Fine root biomass (recent reviews)
Fine root turnover, 0.5 – 1.0 y++"++!$""&" %%  "'$

+!)$et al 

"$ #$&
$"#
#!+
 #$& (    (  
( 

Root litterfall,
if contaminated?
"'et al 

*  

+



Conclusion and future research1.

Forests in Japan has acted as a long term reservoir
of fallout over the past 50 years.

2.

Although 137Cs has remained in forests for a long
period, migrating vertically 5 cm downward during
50 years after deposition.

3.

Probable 137Cs transport from tree roots to soils.
Cs migration processes in soils should be clarified.



3.13 Predicting the future radiocesium distribution in Fukushima from the distribution of global fallout in forested areas in Japan | 183

Thank you for your attention.
Acknowledgment
Department of Forest Site Environment,
Forestry and Forest Products Research Institute of Japan
Institute of Environmental Radioactivity, Fukushima University
Fukushima Chuo Forestry Cooperative

Funding
JSPS KAKENHI Grant Number 25292099
Graduate School of Agricultural and Life Sciences, University of Tokyo

184 | Satoru Miura3.14 Variability in Chernobyl deposited Cs-137
and its influence on the human exposure
Christian Bernhardsson

Presenter: christian.bernhardsson@med.lu.se

Department of Medical Radiation Physics, Lund University / Malmö

Variability in Chernobyl deposited
Cs-137 and its influence on thehuman exposure
Christian Bernhardsson, Medical Radiation
Physics, Malmö, ITM, Lund University

3.14 Variability in Chernobyl deposited Cs-137 and its influence on the human exposure | 185

Outline of the presentation• Illustrating the variability in the Cs-137 deposition horizontallyon the ground after the Chernobyl accident.
• Illustrate the relationship between internal- and external
effective doses to the public in the early- and late phases
after radioactive fallout events.
• Emphasize important factors in the procedures to calculaterisks by means of prospective- and retrospective dosimetry
methods.
• Implications on justified population protection after radioactive
fallout events, e.g. sheltering, relocation, decontamination,
financial support…

Chernobyl 137Cs deposition

186 | Christian Bernhardsson

137Cs deposition and 70 yr prognosis+70 yrs.

1986

2056

Atlas (2009). Cs-137 contamination maps of Belarus and Russia. Issued by the joint program of activities tomitigate the Chernobyl catastrophe within the Union States for 2006-2010 from the budget of the Union State ofBelarus and Russia.

Actual variability in deposition andradiation fields

Conventional mapping (hand-held
NaI(Tl)-detector), 10x10 m2 area

Back-pack NaI(Tl)/LaBr3

Back-pack mapping and fusion of map and data points. >100 m2 area.

3.14 Variability in Chernobyl deposited Cs-137 and its influence on the human exposure | 187

Actual variability in deposition andradiation fields• Varies over time by e.g.
– nature processes (early/late), radionuclide composition,
human influence, location (migration, resuspension)…

• Correct estimates and prognosis of the depositedradionuclides are decisive for the inhabitants health– both immediately after, and in the future.
Radiation exposure above partly decontaminated road

Forest fires in former Soviet countries an issue for several reasons

188 | Christian Bernhardsson

Relationship between internal- andexternal effective doses (over time)• Due to the variability in the radiation fields, the external (andinternal) doses varies for different population groups, e.g. in:ForestFarmland

Kitchen garden

House

SchoolOffice/administration

Assessment of the actual variability indeposited Cs-137 over a surface
HPGe &/or HPIC
Back-pack NaI(Tl)

Soil core (<30 cm á 2cm)
Conventional RPinstruments

5.0m

1.5m

~1.0m

1m

3.14 Variability in Chernobyl deposited Cs-137 and its influence on the human exposure | 189

Examples of the actual variability indeposited Cs-137 in different locations
Example from one settlement in Belarus
1.4

Dose rate, H*(10) [ μSv h-1]

1.2
1.0

ForestOpen garden

0.8

Ploughed fieldNot decontaminated garden

0.6

Decontaminated garden
Inside wooden house

0.4

Inside brick house

0.2
0.0

1

Example of the actual variability indeposited Cs-137 within one location
m

100

50

x
50

190 | Christian Bernhardsson

100mRelationship between internal- andexternal effective dose (over time)
Whole body irradiation:• Internal effective dose
– Whole body counter, partial body counter,measurement of excretion, measurementof foodstuff• External effective dos– Individual dosemeters, mathematicalmodels (based on in situ measurements,
predictions), newretrospective/prospective dosimetry
methods• When to apply what method?

Relationship between average internaland external effective doses (over time)• Average annual effective doses (individual measurements in
Bryansk region villages)
30
25
20

3.0

Observed
rate of decrease (Eext)
Internal

2.5

External
1991– 1993-20% y-1

2.0

1994 – 1998

-12% y-1

1.5

1998 – 2008

-9% y-1

2000 – 2008

-3% y-1

1.0
0.5

15

0.0

10

2008

2006

2004

2002

Year

2000

1998

1996

1994

1992

1990

0

1988

5
1986

Effective dose (mSv y-1)

35

3.14 Variability in Chernobyl deposited Cs-137 and its influence on the human exposure | 191

Example of the variability within asettlement
Type of garden

Averagedose rate(µSv/h)

Cv

Max

Min

(µSv/h)(µSv/h)Decontaminated

0.19

26%

0.35

0.12

Not-decontaminated

0.24

35%

0.60

0.11

Abandoned

0.52

49%

1.08

0.23

• Human influence on the ground surface reduce the intra-site
variability in the external dose rate.

The radiation exposure situation changes
with time in different locations• The effective dose per unit absorbed dose varies in different
locations and over time (a downward migration effect) bothon Eavg and geometry.

Idealised exposure geometries

192 | Christian Bernhardsson

Angular variation of Eeff forphotons with different energy

Exposure geometry and Eavg influenceon the effective dose

ICRP Publication 116

Approach for effective dose assessments• Individual effective dose assessments– Requires a large (devoted) sample group.
– Representative person: probability is less than 5% that aperson drawn at random from the population will receive
a greater dose.
• Model calculations– Requires information on location factors and occupancy
factors.
– Requires information on the effective dose distribution.

3.14 Variability in Chernobyl deposited Cs-137 and its influence on the human exposure | 193

Some key points for consideration• The variability within a specific surface is generally higher
than between different surfaces,– surface dependent and human interference.

• Reference surfaces are important,– the exposure situation varies over time by natural
decay, human interference, and migration down in soil,– several places in inhabited and uninhabited areas.

• When evaluating actions for population protection, thevariability must be taken into consideration and the conceptof reference person should be applied,– internal-/external exposure varies over time, and theirrelative magnitude to the total effective dose.

194 | Christian Bernhardsson

3.15 Radio cesium fixation process to soil analyzed
by monitored radioactivity data of spinach in Fukushima
Elis Holm†, 1† Presenter: elis.holm@gu.se

1 Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden

Dialysis patients might constitute a critical group at a severe internal contamination of radioactive elements. On the other hand dialysis might be an effective tool for decreasing the dose to contaminated persons.
Eight persons were studied for the clearence of 137Cs by dialysis, 6 by haemo dialysis (HD) and 2 byhaemo filtration (HF) or haemo dialysis filtration (HDF). For the 6 HD patients whole volume of dialysis
liquid (about 120 l) was collected. The two HF patients were given reindeer meat contaminated with 137Cs
by the Chernobyl accident and nuclear test fallout before dialysis (ca 15 Bq) to establish the retention of137
Cs. Dialysis fluid was collected in 20 minutes or 40 minutes intervals. 134Cs was used as radochemical yield
determinant. The activity was measured by HPGe-detectors. This study showed that HD and especially HFand HDF are effective methods for removing radiocaesium from the blood pool.
We also studied a HD patient undergoing 131I treatment of thyroid carcinoma. Ten dialysis occasions werestudied for this patient. The results showed a very effective clearance of 131I using HD. There are also otheraspects to consider in such a case, e.g., the change in dosimetry to avoid over- and undertreatment and exposure of personnel during dialysis.
Keywords: Dialysis, Radiocaesium, Radioiodine, Clearance, Man

3.15 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 195

The effect of dialysis on 137Cs
and 131I in man

E. Holm

Department of Radiation Physics,
Gothenburg University

Objectives
Investigate if dialysis is an effective method
for removing radionuclides from the body atinternal contamination.(Emergency situation)
 Find out if persons with end-stage renal
disease constitute a critical group withrespect to internal contamination ofradionuclides.
 Does dialysis have an impact on the isotope
therapy for patients with thyroid cancer?


196 | Elis HolmDIALYSIS
Haemodialysis, HD
 Peritoneal dialysis, PH Haemofiltration, HF
 Heamodialysisfiltration, HDF
In HD the blood flows on one side of asemipermeable membrane (1-1.5 m2)
and the dialysis fluid on the other side.
 In PD the peritoneum acts as asemipermeable membrane with aneffective area of 1.5 m2


3.15 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 197

In HF the blood is led into small fibres andthe very low pressure on the other side of themembranes of the fibres will see to that there
is a transport of fluids from the blood overthe membrane with a velocity of 80-180
ml/minute.
 In HDF the membrane consists of a capillary
tube like in HF but a dialysis fluid flows on
one side of the membrane and blood on theother side like in HD.
 The HDF and HD treatments are more
effective than the HF treatment in removing
small molecules. Haemodialysis. The principle of clearance of the blood..

according to dialysis treatment. There is a constantly
exchanged dialysis concentrate and water on one sideof the membrane, on the other side the blood flows in
opposite direction.

Blood flow (Qb)
Dialysate flow (Qd)

Clearance (Cld)198 | Elis HolmComposition of extracellular fluid and of contemporary haemodialysis fluids (references inparenthesis). †Osmotic active substance.
Contemporary haemodialysis fluids
Interstitial fluid

Extreme range

Typical range[Diem et al.,1970] [Stewart,1989][Stewart,1989]

Sodium (mmol/l)

145

109 - 148

128 – 140

Potassium (mmol/l)

4.0

0 – 4.0

1.0 – 2.0

Calcium (mmol/l)

1.5

0 – 1.75

1.5 – 1.75

Magnesium (mmol/l)

0.5

0 – 1.5

0.5 – 0.85

Chloride (mmol/l)

114

87 - 117

95 – 109

Bicarbonate (mmol/l)

31

0 – 46.7

35 – 40

Glucose† (mmol/l)-

0 – 3011

3.15 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 199

Method
Whole volume of dialysis liquid (about 120 l) or thevolums during intervals (ex. 20 min.) were collected.
 137Cs was collected on cotton-wound cartridge filters
impregnated with copper ferro cyanide or
precipitated from the solution with copper
ferrocyanide. 134Cs was used as radochemical yield
determinant The filters were incinerated and measured by Hp-Ge
gamma spectrometry
 For 131I the samples were measureed directly by
HpGe gama spectrometry and the results decay
corrected to the time of administration.
Study No. 1
14 persons undergoing dialysis.
137Cs
 Dialysis fluid analysed for Whole body counting of patients

200 | Elis HolmStudy No 2
- 8 Persons undergoing dialysis- 2 persons consumed reindeer meat(about 15 Bq of 137Cs) contaminatedfrom nuclear test fallout and theChernobyl accident- Collection of dialysis fluid at intervals
 Whole body counting of one person

The selected dialysis patients. The table show the gender (Male or
Female) of the patient, type of and length of dialysis treatment,
weight of patient, the used filter during dialysis treatment ant thevolume of dialysate achieved during one dialysis session.

Patient Gender Type of
dialysis
1
2
3
4
5
6
7
8

M
M
M
M
F
M
M
M

HD
HD
HD
HD
HD
HD
HF
HF

Number of
Weight ofmonths ofpatient [kg]dialysis
PD 77 + HD 6
70.6
0
41.2
1
84.3
6
76.1
20
68.7
90
70.1
23
82.9
75
70.6

FilterVolume ofdialysate [l]600
600
600
600
600
700
700
700

160
100
165
160
155
160
160
120

3.15 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 201

Study No 3
One patient with the thyroid gland
removed due to cancer
131I Thereafter treated with 350 MBq of This patient was also underwent dialysis
for end-stage renal disease. These twothings happen together independently
for 1 person out of one million.
 Dialysis fluid (HD) collected at intervals
Results Study No 1

Table 1. Patient data and results for a previous study (Josefsson et al., 1995)
Patient Sex
Body
Time on Treat
Body
Body
Effectivemass(kg) dialysis ment
content content half-life
40
137
137
(months
K
Cs
Cs
(Bq)
(Bq)
(days)
1
M
49
42
HD
2700
24
67
2
M
74
2
HD
3500
28
120
3
M
50
15
HD
3300
41
110
4
M
78
1
HD
NM
NM
5
F
48
18
HD
NM
NM
6
F
84
180
HF
4100
ND
7
F
60
10
HD
2500
ND
8
M
68
9
HD
3800
54
130
9
M
85
7
HD
4300
78
75
10
M
78
14
HD
3700
53
201
11
M
60
58
PD
2900
66
120
12
M
78
19
PD
3000
92
232
13
M
63
9
PD
2800
110
780
14
M
69
15
PD
2900
79
89

202 | Elis Holm

Excreation
rate
Bq/24h
0.25
0.16
0.26
0.20
0.22
0.56
0.25
0.28
0.72
0.18
0.38
0.27
0.10
0.61

Results Study No. 1 contd.
The effective half-life for radiocaesium
was about the same as for persons withnormal renal functions.
 15 hours of haemodialysis during aweek achieve the same elimination of
137Cs as normal kidney Haemodialysis is more effective thanperitoneal dialysis
Results for Study No 2

3.15 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 203

The activities of 137Cs in the individual dialyatesof the selected dialysis patients
Patient Gender Type of Number of months Weight ofdialysis of dialysis
patient [kg]1
MHD
PD 77 + HD 6
70.6
2
M
HD
0
41.2
3
M
HD
1
84.3
4
M
HD
6
76.1
5
F
HD
20
68.7
6
M
HD
90
70.1
7
M
HF
23
82.9
8
M
HF
75
70.6

Filter
600
600
600
600
600
700
700
700

.

137

Volume of A ( Cs) [mBq]dialysate [l]16061192100
not meas.
16551577160
905136155
732110160
38057160
39960120
25638

Activity of 137Cs in intervals of 40 minutes per dialysis occasion - dialysis patient 7
450

HF

400

HDF

Activity [mBq] -

137

Cs

350
300
250
200
150
100
50
0

Before Intake In intervalsof 40 min

204 | Elis Holm

Dialysis at day 2 In
intervals of 40 min

Dialysis at day 5 In
intervals of 40 min

Dialysis at day 7 In
intervals of 40 min

Dialysis at day 9 In
intervals of 40 min

Dialysis at day 12 In
intervals of 40 min

Activity of 137Cs in intervals of 20 minutes per dialysis occasion - dialysis patient 8
350

250
200
150
100
50
0

Before Intake In
Dialysis at day 2 In Dialysis at day 5 In Dialysis at day 7 In Dialysis at day 9 In Dialysis at day 14 Dialysis at day 16
intervals of 20 min intervals of 20 min intervals of 20 min intervals of 20 min intervals of 20 min in intervals of 20 In intervals of 20minmin

Accumulated activity of 137Cs in intervals of 40 minutes per dialysis occasion- dialysis patient 7
2000
1800

137

Accumulated Activity [mBq] - Cs

Activity [mBq] -

137

Cs

300

1600
1400
1200
1000
800
600
400
200
0

Before Intake Inintervals of 40 min

Dialysis at day 2 In
intervals of 40 min

Dialysis at day 5 In
intervals of 40 min

Dialysis at day 7 In
intervals of 40 min

Dialysis at day 9 In
intervals of 40 min

Dialysis at day 12 In
intervals of 40 min

3.15 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 205

Accumulated Activity of 137Cs in intervals of 20 minutes per dialysis occasion- dialysis patient 8

137

Accumulated Activity [mBq] - Cs

2500

2000

1500

1000

500

0

Before Intake Inintervals of 20 min

Dialysis at day 2 In Dialysis at day 5 In Dialysis at day 7 In Dialysis at day 9 In Dialysis at day 14 in Dialysis at day 16 In
intervals of 20 min intervals of 20 min intervals of 20 min intervals of 20 min intervals of 20 min intervals of 20 min

Total activity of137

Cs per dialysis vs time - dialysis patient 7

1400
1200
1000

Activity [mBq] -

137

Cs

800
600
400
200
0
-200
-400
-600

0

10

20

30

Time [days]

206 | Elis Holm

40

50

Total activity of137

Cs per dialysis vs time - dialysis patient 8

1400

Activity [mBq] -

137

Cs

1200
1000
800
600
400
200
0

0

10

20

30

Time [days]

Results for Study No 3

3.15 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 207

Activity concentration (Bq/ml) of 131I at 20 min. interval
during 9 dialysis occasions. Data decay corrected to time ofadministration
Dialysis I-131

Activity concentration, Bq/ml

10000
Series1
Serie2
Series3

1000

Series4
Series5
Series6
Series7

100

Series8
Series910Time, minutes

1
0

50

100

150

200

Total activity (MBq) of 131I in dialysis liquid ateach treatment decay corrected to time ofadministration.

Accumulated activity, MBq

90
80
70
60
50
40
30
20
10
0
1

2

3

4

5

6

Dialysis occation

208 | Elis Holm

7

8

9

10

Conclutions for 137Cs-Dialysis is an effective tool for removing
137Cs from the body
-HDF is more effeftive than HF, HD, andPD with respect to removing small
molecules
The effective half-life in the body using
dialysis is only 8-11 days compared tonormally 70-100 days

Conclutions for 131I











HD is an effective method for removing 131I from the blood pool.
Dialysis has an important impact on the therapeutic doseOf the administered 350MBq, 156MBq were recovered in the
dialysis liquid
The remaining activity might be found in the filter or evaporated
during treatment or transport of the samples.
Or may be the fractional uptake is lower for a person with thethyroid gland removed and the remaining activity was removed
with faeces?
If a person is consuming stable Iodine the uptake is probably
lower.
The dialysis patients do not constitute a critical group forinternal contamination of 131Cs or 131I since the removal bydilaysis is effective.
However the effect of the 131I treatment might be less effective
especially if dialysis is performed shortly after administration.

3.15 Radio cesium fixation process to soil analyzed by monitored radioactivity data of spinach in Fukushima | 209

Suggestions for further work
Repeat study with larger amount of 137Cs
consumed Study patients wih normal kidneys undergoing
dialysys such as at poisioning.
131I with normal Thyroid Study patients forfunction Study other radionuclides used in nuclear
diagnostic medicine, 99Tcm (99Tc), 75Se etc.
 What is the effect of dialysis on naturalradionuclides, U, Ra, Po etc?
Thank you for your Attention

210 | Elis Holm

3.16 Uranium levels in mining lakes in Southern Sweden
Rimon Thomas†, 1, Juan Mantero1, Mats Isaksson1, Christoffer Rääf2,
Eva Forssell-Aronsson1, Elis Holm1† Presenter: rimon.thomas@gu.se

1 Department of Radiation Physics. Institute of Clinical Sciences. Sahlgrenska Academy at University of Gothenburg, Gothenburg
2 Department of Medical Radiation Physics, Institute of Translational Medicine, Lund University, Malmö

Sweden is a major metal mining country in the European Union and the mining activity results in large
quantities of generated waste. The effect of mining activities on hydrological regimes has been studied atmany locations worldwide where one of the major threats is the acid mine drainage water. In this work, acidmine water open pits will be studied, so called pit lakes. There is a growing awareness of the environmental
risk associated with these mining lakes, where several studies are focused on metallic elements and/or remediation activities, but few data related to radionuclides behavior at pit lakes can be found in the literature
today.
This work is the first stage of a project financed by the Swedish Radiation Safety Authority (SSM) that will
generate a database with results of naturally occurring uranium isotopes (238U, 234U and 235U) in waters fromthese sites that may enhance their activity concentrations affecting the surrounding areas through drainage
waters or even contribute to increase the external doses received by people visiting these sites for recreation
purposes.
Alpha spectrometry with PIPS detector was performed within a set of 25 water samples belonging to 15
different pit lakes from the Southern part of Sweden. A wide range of 238U activity concentration was found,with values from 2 to 700 mBq/kg. Since the average value of the 238U activity concentration in non-affectedlake water is around 30 mBq/kg, some of the studied pit lakes have enhanced U levels in superficial water.
Other parameters as temperature, pH, oxidation-reduction potential (ORP), specific conductance, dissolved
oxygen and salinity are also determined in the samples.
Keywords: radioecology, uranium isotopes, water, mining lakes

3.16 Uranium levels in mining lakes in Southern Sweden | 211

URANIUM LEVELS IN MINING LAKES IN
SOUTHERN SWEDEN

RIMON THOMAS PHD STUDENT

Behavior of radionuclides in mining lakes in Sweden
R. Thomas1, J. Mantero1, M. Isaksson1, C. Rääf2,
E. Forssell-Aronsson1, E. Holm1
1Department of Radiation Physics. Institute of Clinical Sciences. Sahlgrenska Academy at

University of Gothenburg, Gothenburg

2Medical Radiation Physics, Institute of Translational Medicine, Lund University, Malmö

University of Seville, Centro Nacional de Aceleradores (CNA)and CITIUS Lab
Risø Lab

Project funded by SSM

212 | Rimon Thomas, Juan Mantero, Mats Isaksson, Christoffer Rääf, Eva Forssell-Aronsson, Elis Holm

Mining in Sweden – A brief history
1200: Earliest documented mining

1600: Falu copper mine responsible for ~66% of the worlds copper
production
1750: 70% of Swedens export was iron from mines
1924: Bolidengruvan became the biggest and richest goldmine inEuropeUp to 3000 mines have been recorded in Swedish history

What is a mining lake?

3.16 Uranium levels in mining lakes in Southern Sweden | 213

Mineral Extraction
Examples:Pyrite𝐹𝐹𝐹𝐹𝑆𝑆2 + 14𝐹𝐹𝐹𝐹 3+ + 8𝐻𝐻2 𝑂𝑂 → 15𝐹𝐹𝐹𝐹 2+ + 2𝑆𝑆𝑂𝑂42− + 16𝐻𝐻 +Sphalerite𝑍𝑍𝑍𝑍𝑍𝑍 + 2𝑂𝑂2 → 𝑍𝑍𝑍𝑍2+ + 𝑆𝑆𝑂𝑂42−
Galena

𝑃𝑃𝑃𝑃𝑆𝑆 + 2𝑂𝑂2 → 𝑃𝑃𝑃𝑃 2+ + 𝑆𝑆𝑂𝑂42−

Chalcopyrite

𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝑆𝑆2 + 4𝑂𝑂2 → 𝐶𝐶𝐶𝐶2+ + 𝐹𝐹𝐹𝐹 2+ + 2𝑆𝑆𝑂𝑂42−

214 | Rimon Thomas, Juan Mantero, Mats Isaksson, Christoffer Rääf, Eva Forssell-Aronsson, Elis Holm

Uranium-238 levels in literature• Non affected waters, approximately 25mBq/L• Affected waters from Uranium mining, 16100mBq/L [Strømman
et al. 2013]• Guideline from WHO in drinking waters, 180mBq/L
Uranium, Thorium and Polonium levels in many non-Uranium
Swedish mines currently unknown…

Up until now

ORGANIZATION NAME (CHANGE HEADER
USE THE INSERT TAB-HEADER/FOOTER)

Project status
Sampled 40 mining sites

WaterSediments
Soil
Measurements:

External dose (µSv/h)
pH, ORP(mV), C(µS/cm), DO(mg/L)

3.16 Uranium levels in mining lakes in Southern Sweden | 215

Results – Water samples
24 water samples analyzed so far,In the rangeof [Bq/Kg]

U-238

U-234

Th-230 andTh-232

Po-2100.1 – 1250

0.1 – 1600

No significant results

Next stepMove to a new (permanent) radiochemistry lab

Finish the sample preparation and measure & analyze all thesamplesFor some relevant lakes:• Use the data for dose assessment

Choose one lake, for a deeper study:• Seasonal variation• Depth profile of uranium

216 | Rimon Thomas, Juan Mantero, Mats Isaksson, Christoffer Rääf, Eva Forssell-Aronsson, Elis Holm

3.17 Biokinetics and radiobiological effectsof low dose exposure from radiohalogens in rodents
Johan Spetz†, 1, Britta Langen 1, Eva Forssell-Aronsson1† Presenter: johan.spetz@gu.se / britta.langen@gu.se

1 Dept of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy
at University of Gothenburg, Sweden

Iodine is essential for the normal function of the thyroid gland. Hence, radioactive iodine is taken up in
the thyroid at a high rate, but it also accumulates in other tissues if to a much lower extent. Exposure to131
I through inhalation or ingestion can occur after a nuclear power plant accident, which can cause thyroid
cancer or other thyroid disorders later on in life. Radiohalogens such as 125I, 131I and 211At are also used inclinical research and applications. Accurate knowledge of their biodistribution is important for absorbed dose
calculation, risk estimation of exposure, and for optimal treatment planning. Dosimetric estimation requires
known biokinetics and biodistribution of these radionuclides in various tissues. This has been relatively welldetermined for mice, despite the difficulty to sample small organs and entirely excise them separately in mice.
Thus the difference in size between rats and mice makes organ sampling easier in rats. Still there has been
limited amount of data for rats.
In this work, we studied the biodistribution of 125I, 131I and free 211At in rats and determined absorbed doses
from these radionuclides to various organs and tissues. Male Sprague Dawley rats were injected simultaneously with 0.1–0.3 MBq 125I- and 0.1–0.3 MBq 131I-, or 0.05–0.2 MBq 211At. The rats were killed and dissected 1 hour to 7 days after injection. Radioactivity measurements were performed on the organs and tissues
collected, activity concentrations were determined and mean absorbed doses were calculated. We also studied
biological effects (genome-wide transcriptional regulation) of i.v. administered 0.064–42 kBq 211At in female
BALB/c nude mice after 24 h. Furthermore, we studied the effect that time-of-day of exposure initiation
has on biological response in various tissues in BALB/c nude mice 24 h after i.v. injection with 90 kBq 131I.
The biodistribution of 125I- was similar to that of 131I-. All three radionuclides were accumulated selectively in the thyroid gland; but the activity concentration of radioiodine was about five times
higher than that of 211At. The activity concentration of 211At was higher than that of radioiodine inall extrathyroidal tissues. The mean absorbed dose was highest to the thyroid. 131I gave the highest
dose to the thyroid at t=∞, and 211At gave the highest dose to all other tissues studied.
Regarding biological effects of internalized radiohalogens, we found a non-monotonous dose-response
behavior with a stronger effect at lower absorbed dose than at higher absorbed dose (Figure 1). We also
demonstrated that the time-of-day when 131I was administered strongly influenced the genome-wide transcriptional regulation in various tissues. However, it remained unclear whether circadian rhythm also had
an impact on the biokinetics of 131I uptake. Future studies will investigate if bio- distribution depends ontime-of-day of administration.

3.17 Biokinetics and radiobiological effects of low dose exposure from radiohalogens in rodents | 217

Fig.1 Dose-response of transcriptional regulation after 24 h following 211At administration.

218 | Johan Spetz, Britta Langen, Eva Forssell-Aronsson

BIOKINETICS AND RADIOBIOLOGICAL EFFECTS OF LOW DOSEEXPOSURE FROM RADIOHALOGENS IN RODENTS
Johan Spetz, Britta Langen, Eva Forssell-Aronsson

Overview•

Biokinetics of 125I, 131I and 211At in vivo•••

Radioactivity measurements in normal organs
Activity concentrations and absorbed doses in normal organs

Biological effects of low-dose radionuclide exposure in vivo•••

Gene expression and microarray method
Dose-response of 211At in mouse normal tissues
Dose-response of 131I in mouse normal tissues
in dependence of time-of-day of exposure initiation

3.17 Biokinetics and radiobiological effects of low dose exposure from radiohalogens in rodents | 219

Background•

Iodine is essential for thyroid function•

Also taken up to a smaller extent in other organs•

Exposure to radioidine can occur after nuclear powerplant
accidents•

Radiohalogens are also used in medical applications andresearch••e.g. 125I, 131I, 211At

Biodistribution knowledge neccessary for e.g. dosimetry & risk
estimation

220 | Johan Spetz, Britta Langen, Eva Forssell-Aronsson

Study design•

Male rats i.v. injected with ~200 kBq 125I, 131I and 211At•

Animals killed at 1 h to 7 d after injection•

Organs excised and radioactivity measurements performed

Wallac 1480 WIZARD 3’’ NaI(Tl) gamma counter

3.17 Biokinetics and radiobiological effects of low dose exposure from radiohalogens in rodents | 221

Study design•

Male rats i.v. injected with ~200 kBq 125I, 131I and 211At•

Kept on iodine-deficient food for 3 weeks before injections•

Animals killed at 1 h to 7 d after injection•

Organs excised and radioactivity measurements performed•

Absorbed doses calculated using the MIRD formalism

Radioactivity in thyroid
18
16

Thyroid %IA

14
12

I-131

10

I-125

8

At-211

6
4
2

0
0

24

48

72

222 | Johan Spetz, Britta Langen, Eva Forssell-Aronsson

96

120

144

168

192

Absorbed doses (mGy/MBq)
Tissue

131I

211At

Blood
Brain
Heart
KidneyLarge intestine
Liver
Lung
MuscleSalivary glands
Small intestine
SpleenStomachThyroid

8.6 (0.4)
0.82 (0.07)
16 (1)
7.0 (0.4)
4.2 (0.2)
5.9 (0.4)
6.5 (0.3)
7.1 (1.2)
5.0 (0.5)
10 (2)
4.6 (0.6)
64 (5)
21000 (2000)

98 (3)
190 (20)390 (20)210 (40)230 (20)1100 (100)130 (10)280 (10)340 (50)1000 (50)1200 (100)18000 (4000)

Note. Data are given as the mean (SEM).

3.17 Biokinetics and radiobiological effects of low dose exposure from radiohalogens in rodents | 223

Overview•

Biokinetics of 125I, 131I and 211At in vivo•••

Radioactivity measurements in normal organs
Activity concentrations and absorbed doses in normal organs

Biological effects of low-dose radionuclide exposure in vivo•••

Gene expression and microarray method
Dose-response of 211At in mouse normal tissues
Dose-response of 131I in mouse normal tissues
in dependence of time-of-day of exposure initiation

Study of biological effects
Gene expression and microarray analysis
poly-peptide chain

foldedproteinmodified
proteinnucleusnucleusprotein folding
translation
splicing

post-translational
modification
protein localization

Transcriptomic analysis using the Illumina MouseRef-8 Whole Genome Beadchip platform
High-throughput analysis of more than 19,100 unique genes and around 25,600 transcripts

224 | Johan Spetz, Britta Langen, Eva Forssell-Aronsson

Workflow – Langen et al., 2013. JNM. & Rudqvist et al., 2012. EJNMMI Res.
tissue sample
preparation

211At

absorbed dose
dose rate
time point

female BALB/c nude mice

Nexus Expression
kidneysliver
lungs
spleenstatisticalprocessing

Illumina
microarray
platform

thyroidabsorbed dose calculation:
MIRD formalism

main analytical endpoints
o significantly regulated transcriptso shared transcripts between
tissues or conditions
o signature gene regulation
─ ionizing radiation-associated─ thyroid hormone-respondingo profiling of cellular functions related
to enriched biological processes

Total transcriptional regulation after 24 h

Britta Langen, PhD thesis 2015; Gothenburg, Sweden.

3.17 Biokinetics and radiobiological effects of low dose exposure from radiohalogens in rodents | 225

Workflow – Langen et al., 2015. EJNMMI Res.
131I

absorbed dose
dose rate
time point
time of day

12:00
9:00 15:00

Nexus Expression
kidneysliver
lungs
spleenstatisticalprocessing

Illumina
microarray
platform

thyroid

female BALB/c nude mice

injection of
90 kBq 131I orphysiol. saline

tissue sample
preparation+24horgan excision
exactly 24h
after eachtime of day

absorbed dose calculation:
MIRD formalism

main analytical endpoints
o significantly regulated transcriptso shared transcripts between
tissues or conditions
o signature gene regulation
─ ionizing radiation-associated─ thyroid hormone-respondingo profiling of cellular functions related
to enriched biological processes

The number of significantly regulated transcripts isdependent on the time-of-day of administration

Absorbed dose
Mean absorbed dose (mGy)
Kidney cortex
Kidney medulla
Liver
Lungs
SpleenThyroid

2.1
2.1
1.4
2.2
0.75
5 900

Mean absorbed dose (mGy)over 24 h from 90 kBq 131I

Langen et al., 2015. EJNMMI Res.

226 | Johan Spetz, Britta Langen, Eva Forssell-Aronsson

Conclusions•

The biokinetics of radioiodine and astatine are different•

The thyroid selectively accumulates iodine and astatine••

Non-monotonous dose-response of transcriptional gene
regulation upon radionuclide exposure•••

About five times less astatine

strong effects at (very) low absorbed dose
effects not directly proportional to absorbed dose level

Circadian rhythm influences strength of biologicalresponse to absorbed dose

Outlook
Upcoming study:
Do uptake-kinetics vary with circadian rhythm?

3.17 Biokinetics and radiobiological effects of low dose exposure from radiohalogens in rodents | 227

Chapter 4
Workshop at Stockholm University

Japanese-Swedish Radioecology Workshop
Stockholm University, Sweden, 3-4 September 2015
(Meeting room ‘Bergsmannen’ in the building ‘Aula Magna’)

The meeting location:

Metro (Tbana)stationMeetingroom!
The red triangle shows the main entrance to Aula Magna – from there there will be signs to the meeting room
‘Bergsmannan’. See http://tinyurl.com/obn6gu8 for a zoomable map.

Getting to Stockholm University from central Stockholm:

230 | Sweden-Japan Workshop of Radioecology for Students, 2015

Take the red line on the Metro (Swedish: Tunnelbana or T-bana), final destination Mörby Centrum.
Get off at ‘Universitet’. A map of the T-bana network can be found here: http://sl.se/ficktid/karta/
vinter/Tub.pdf (the numbers in brackets show the number of minutes travel from the central station 'TCentralen').
More information in English about public transport in Stockholm can be found here http://sl.se/en/

Transport to/from the airport:
If you are coming straight from the airport (Arlanda) to the meeting, taking a taxi is probably thefastest and easiest option. Make sure you use one of the larger companies such as Taxi Stockholm,
Taxi 020 or Taxi Kurir all of whom have fixed prices from the airport.
If you are travelling to a central hotel, train or bus is probably better –For those of you arriving at Arlanda airport (https://www.swedavia.com/arlanda/), the quickest (butmost expensive) option is the Arlanda Express train: https://www.arlandaexpress.com/. It takes 20
mins to Stockholm Central station. There are also airport buses: http://www.flygbussarna.se/en whichtake c. 40 minutes to Cityterminalen at Stockholm Central station but are half the price.

Chapter 4

Workshop at Stockholm University | 231

Schedule
Time

Activity

Speakers

08:30

Welcome, round the table introductions

09:00

The Chernobyl accident - consequences andradiation risks in Sweden nuclear accident

Leif Moberg, former Research Director of theSwedish Radiation Safety Authority

09:30

Agricultural implications of Fukushima

Keitaro Tanoi for Tomoko Nakanishi,
University of Tokyo

10:00

tea/coffee break

Session 1: Wildlife
10:30

Ecological measurements and monitoring of large
terrestrial animals in Sweden

Robert Weimer, Swedish University ofAgricultural Sciences

10:50

Radiocesium contamination in wild boar

Keitaro Tanoi, University of Tokyo

11:10

Wetland radioecology post-Chernobyl and doses
to frogs from Cs-137

Karolina Stark, Stockholm University

11:30

Current conditions of fisheries, radioactive
contamination of seafoods, and fish ecologies onfishing ground in Fukushima

Tomoya Hori, Kyoto University

11:50

Role of trophic transfer in benthic ecosystems off
Fukushima

Clare Bradshaw, Stockholm University

12:10

Understanding of the consumer’s purchaseintentions on salted salmon produced in Miyagi
prefecture in Japan and its determinant factors

Takashi Suzuki, University of Tokyo

12:30

Lunch

Session 2: Plant uptake
13:45

Long-term desorption kinetics of Cs from soils

Kento Murota, University of Tokyo

14:05

Interception and storage of wet depositedradionuclides in crops

Stefan Bengtsson, formerly Swedish
University of Agricultural Sciences andFukushima University

14:25

Comparing Cs dynamics in two rice cultivars,
Milyang23 and Akihikari, by tracer experiments

Shuto Shiomi, University of Tokyo

14:45

The analysis of characterization of cesium
accumulation in wild radish

Nanami Oshima, Kyoto University

15:05

Phytoremediation - Is it possible to use plants toclean up after radioactive releases?

Maria Greger, Stockholm University

15:25

The impact of potassium fertilization:
Investigation by the radioisotope tracer
experiment

Natsuko I. Kobayashi, University of Tokyo

232 | Sweden-Japan Workshop of Radioecology for Students, 2015

15:45tea/coffee break

16:15

Ecosystem modelling for a future high-level
nuclear waste repository in Forsmark, Sweden

16:35 –
17:30

General discussion

18: 30Evening dinner at Stockholm University

Ulrik Kautsky, Swedish Nuclear Fuel andWaste Management Company

Chapter 4

Workshop at Stockholm University | 233

4.1 The Chernobyl accident – consequences
and radiation risks in Sweden
Leif Moberg

Presenter: Leif Moberg

Presentation at theJapanese-Swedish Radioecology Workshop, Stockholm University, 3-4 September 2015

Former Research Director at the Swedish Radiation Safety Authority.

The Chernobyl accident – consequences
and radiation risks in Sweden
Leif Moberg**Former Research Director at the Swedish Radiation Safety Authority
E-mail: lcmoberg@gmail.com

Content• The radioactive cloud and deposition in Sweden• Initial countermeasures• Consequences in the environment• Dose limits for food products• Radiation doses to the Swedish population• Communication of decisions and radiation risks• Experiences and lessons learned

234 | Leif Moberg

Forsmark nuclear power plant

In the morning 28 April 1986, the Swedish authorities were informed
about a possible radioactive leak at the Forsmark NPP.

Employees at Forsmark NPP were evacuated[Picture from an article by Anders Marklund inStrålskyddsnytt Nr 1, 1996]

The Soviet news agency TASS in the evening of 28 April 1986: An accident has
occurred at the Chernobyl nuclear power plant, one of the reactors isdamaged. Actions are taken to handle the consequences of the accident.
Injured people are treated. A governmental commission has been appointed.

4.1 The Chernobyl accident – consequences and radiation risks in Sweden | 235

The origin of the radioactive contamination at Forsmark was a reactor in Ukraine.

Chernobyl – a catastrophy

01.23 local time, 26 April 1986

Increased I-131 activities in air occurred at two occasions, the last days of April
and 8-10 May 1986.
[Chernobyl – its impact in Sweden, SSI-rapport 86-12]

236 | Leif Moberg

Ground deposition of Cs-137

European Commission ©EU/IGCE

Deposition of Cs-137 in Sweden

4.25 PBq or about 5% of
the Cs-137 released from
Chernobyl deposited in
Sweden About 5 % of the released
Cs-137 also deposited in
the Baltic sea.


4.1 The Chernobyl accident – consequences and radiation risks in Sweden | 237

Detected radionuclides
Sr-90
Zr-95
Nb-95
Mo-99
Ru-103
Ru-106
Rh-105
Sb-127
Te-129m
Te-131m
Te-132B
I-131
I-133

Cs-134
Cs-136
Cs-137
Ba-140La-140Ce-141
Ce-143
Pu-238
Pu-239+240
Pu-241
Am-241
Cm-242……….

Possible actions/countermeasures• Staying indoors/sheltering• Evacuation/relocation• Remediation, decontamination

Not judged to benecessary in
Sweden• Iodine prophylaxis• In this presentation: radiation doses and Cs in
the environment

238 | Leif Moberg

External doses


Average dose fromplume passage 0.01
mSv.
May have been
considerably higher incertain areas.

Average dose fromground deposition 0.6
mSv during 50 years.
 Highest dose fromground deposition 4
mSv first year and 33
mSv during 50 years.
[Graphs from an article by RobertFinck in Strålskyddsnytt Nr 1, 1996]

What is an acceptable radiation dose?
Basis for decisions in 1986:
 Highly justified to avoid long term individual doses (50 years)
above 500 mSv
 Not justified to take measures with great social andeconomical impact for society or individuals to avoid longterm doses less than 50 mSv
 The authority (SSI*) chose the lower end of the interval, i.e.
50 mSv in 50 years

 The dose during the first year should be less than 5 mSv and in
the following years less than 1 mSv/y in average*The Swedish Radiation Protection Authority (SSI), since 2008 the Swedish Radiation Safety
Authority (SSM)

4.1 The Chernobyl accident – consequences and radiation risks in Sweden | 239

Food limits in Sweden


In May 1986: 300 Bq/kg Cs-137
This should guarantee a longterm average radiation dose lessthan 1 mSv/y Annual intake less than 50 000 Bq
Cs-137 incl. contribution from Cs134


In June 1987: the limit forreindeer meat, game meat, fishfrom lakes, wild berries,
mushroom and nuts wasincreased to 1 500 Bq/kg.
Diet recommendations issued by the
Swedish National Food Agency in 1987

Cs-137 (Bq/kg) in the body
Reindeer herdsmen

Farmers Gävle area

SSM reference group StockholmCountry average[Pictures : Swedish
Radiation Safety Authority]

240 | Leif Moberg[Rolf Falk, Christopher Rääf,
Göran Ågren et al]Internal doses from foodStudies based on fallout fromthe atmospheric nuclear
bomb tests identified reindeer
farmers as the most criticalgroup in Sweden.
 Average 50 year dose fromeating food with Cs-137 andCs-134 is 13.2 mSv in thisgroup.
[Rääf , Strålskyddsnytt Nr 1, 2006]

Reindeer

Northern
SwedenCs-137 in reindeer in the south of Västerbotten[B Åhman, Strålskyddsnytt Nr 1, 2006

4.1 The Chernobyl accident – consequences and radiation risks in Sweden | 241

Consequences for reindeer industry• 78% of reindeer meat was destroyed the firstyear (>300 Bq/kg) = great cost and adverse
conditions for reindeer herders– 0.003 mSv to average Swede (22000 reindeer
between 300 – 1000 Bq per kg)• Second year 29 % destroyed (>1500 Bq/kg);
some years later less than 1% destroyed; aresult of various countermeasures

Agriculture
Cows not allowed to graze
outdoors until the area had
been cleared based on grassmeasurements.
 The first harvest was performedby cutting the straws at anincreased height.
 Increased frequency ofploughing combined withpotassium fertilizer mosteffective countermeasure.
 Consequences mainly in 1986
and 1987


242 | Leif Moberg[Rosén . Strålskyddsnytt Nr 1, 2006]

Milk (Cs-137 Bq/l, country average)

Average concentration July –December 1986

[P Andersson, Strålskyddsnytt Nr 1, 2006]

Cs-137 in forests

The content in mushrooms can be very high (and still be above the food limit
in some areas of Sweden)
The content in wild berries is on average one tenth of that in mushrooms.
The content in moose, which is important for hunting in Sweden, follow theCs-137 content in wild berries.
Cecium-137 i älgkött, medelvärden

Cs-137 in moose (Bq/kg)

Bq/kg

Gränsvärde för försäljning

1500

Västerbottens län
Gävleborgs län
Västmanlands län
Västernorrlands län

1000

2002

2001

2000

1999

1998

1997

1996

1995

1994

1993

1992

1991

1990

1989

1988

1987

1986

1985

1984

1983

1982

1981

0

1980

500

1979

[Data fromthe databaseat SSM]

4.1 The Chernobyl accident – consequences and radiation risks in Sweden | 243

Cs-137 in lakes
Cs-137 in pike (Bq/kg fw)
 1987 – Cs-content in fish

above 1500 Bq/kg in 14000
lakes
 2010 – Cs-content in fish
predicted to be below 300
Bg/kg on a regional basis
 The content in fish frominland lakes can still be
above 1500 Bq/kg Cs-137 insome areas.

[Håkanson, Strålskyddsnytt Nr 1, 2006]

small perch
large perch

pike

Cs-137 in pike, large and small perchin Storsjön
Cs-137 in pike in 178 lakes 19931995[Vår Föda Nr 3, 1996]244 | Leif Moberg

Risk communication pre-internet
Information channels 1986
 Media Press releases
 Reports and brochures
 Public meetings
 Telephone and fax
 Via other authorities and decision-makers
In addition today
 Internet (web pages, social media, e-mails…)

Brochure distributed tohouseholds in the counties of
Uppsala, Västmanland andGävleborg 26 May 1986

Brochure distributed to households
in the counties of Västernorrland, SW
Västerbotten, E Jämtland and NE
Gävleborg 4 June1986

See Appendix 1 for the entire brochure.

4.1 The Chernobyl accident – consequences and radiation risks in Sweden | 245

Brochure
distributed to
all households
in Sweden(autumn 1986)

After Chernobyl?

Information about theconsequences in
Sweden of the accident
in Chernobyl
See Appendix 2 for the entire brochure.

Experiences and lessons learned 1
 Comparing risks is difficult

 Cigarette smoking, driving a car, being struck by lightning,drowning, x-ray examinations, radon in houses

 Some risks are taken voluntarily others not, some risks(may) cause health effects later in life, other can cause
death instantaneously Individuals interpret similar risks in different ways

 Differences in how laymen and experts interpret risks
associated with radiation

 ”small radiation doses are harmless”, i.e. harmless in a more
everyday terminology and in comparison with many other risks
we subject ourselves to on a daily basis

 ”Ionising radiation” itself evokes a sense of danger

246 | Leif Moberg

Experiences and lessons learned 2
 Confidence Complete openness in providing information andassessment of the situation as it becomes
available is necessary

 Measurements of radiation levels (ground,
foodstuffs)
 Important to communicate rapidly

Experiences and lessons learned 3
Finally, Society must guarantee a certain minimum
protection level but in the end it is theindividual who decides what protection
he/she wants
 Therefore, authorities are responsible for boththe societal protection level and for providing
the individual with adequate information formaking his/her own assessments.

4.1 The Chernobyl accident – consequences and radiation risks in Sweden | 247

Summary Sweden Larger consequences than expected from a nuclear accident
abroad 5 % of released cesium-137 deposited in Sweden (4,25 PBq)
 Only cesium-137 today, in forests and lakes
 No observable radiation induced health effects expected Many people have felt a lower quality of life A major radioecological research program was initiated Substantial improvements in nuclear emergency
preparedness after 1986248 | Leif Moberg4.2 Agricultural implications of Fukushima nuclear accident
Tomoko M. Nakanishi†,1† Presenter: atomoko@mail.ecc.u-tokyo.ac.jp

1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

More than 4 years have passed since the Fukushima Daiichi nuclear power plant accident. More than
110,000 people who were evacuated from the area remain at locations different from where they used
to live. Immediately after the accident, the Graduate School of Agricultural and Life Sciences at Tokyo
University created an independent team from a wide variety of research specialties including soil, vegetation, animal life, fishing, and forestry. This team entered sites in the affected areas immediately after
the accident and initiated research studies. They are continuing their research to determine the effectsof the accident on agricultural fields. Our Graduate School includes many research areas, and many facilities such as meadows, experimental forests, and farming fields are associated with the school. Employing these facilities, many on-site research studies have been conducted in Fukushima Prefecture.
It was important to the Graduate School of Agricultural and Life Sciences that the results of these researchstudies contribute to the recovery of the affected area; therefore, we have endeavoured to officially publish theresults. For example, 11 meetings have been held since November 2011 to report research results. The objectiveof these meetings was to provide a simple explanation of the results of the research studies so that the generalpublic could understand them. We published two books about the research on Fukushima, one through Springer
Publishing Company and the other as an easy-to-understand book written in Japanese. The books were published to allow a wide range of ordinary people to have a correct understanding of the impact of radioactive material on agricultural, forestry, and fishing products and the countermeasures taken against radiation exposure.
Based on the scientific data from these studies, we initiated lecture classes for students and for thegeneral public to explain the behaviour and movement of radioactivity in the environment and to provide basic knowledge about radioactivity. To provide firsthand experience of radio-ecology in the environment for students, we periodically hold open lectures in the contaminated fields or mountains.
A major feature of the radioactive fallout is that radioactive caesium (Cs) has remained at the initial contact sites and has moved very little since the initial event. In animals, metabolic activity has reduced the radioactivity level over time at a much faster rate than the physical half-life. The biologicalhalf-life in animals was estimated to be less than 100 days. Soil plays a major role in immobilising fallout. When fallout nuclides are absorbed into the soil, little of the radioactive Cs is taken up by plants
growing there. In the mountains, radioactive Cs was transferred gradually from vegetative litter tosoil and subsequently moved very little, even when the soil was washed with heavy rain. The mechanism of contamination by radioactive nuclides is completely different from that of heavy metals.
Similar to the agricultural environments of other Asian countries, Japan is located in a monsoon
area, with many paddy fields used to grow rice. However, the climate and agricultural environment
in Japan differ from those near Chernobyl; therefore, it is important to gather information regarding the movement and features of fallout that are specific to Japan from an agricultural point of view.
It appears that the recovery of the agricultural, forestry, and fishing industries in Fukushima Prefecture willtake quite some time, but the Graduate School of Agricultural and Life Sciences at Tokyo University willcontinue to support the recovery of these industries in the future.
4.2 Agricultural implications of Fukushima nuclear accident | 249

Keywords: Fukushima Daiichi nuclear power plant accident, radiation contamination, agriculture, radio-ecology

チューリップTomoko M. Nakanishi(substitute speaker; Keitaro Tanoi)
The slides were the same as 3.1 (page. 36-54)

250 | Tomoko M. NakanishiThank	
  you	

4.3 Monitoring of 137Cs in large terrestrial animals in Sweden
Robert N. Weimer

Presenter: robert.weimer@slu.se

Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU)

Monitoring of 137Cs in large
terrestrial animals in Sweden
Robert N. Weimer (MSc in Biology)
Licentiate-student at the Department of Aquatic Sciences and Assessment, UppsalaE-mail robert.weimer@slu.se

Forest or Mixed Ecosystems:
Monitoring or investigations of 137Cs in animals, such as:SpeciesWhen

PurposeMoose (Eurasian elk) (Alces alces)
Wild boar (Sus scrofa)
Brown bear (Ursus arctos)
Lynx (Lynx lynx)- autumn- all year
- autumn- spring

meat
meat
meat
mgmt

4.3 Monitoring of 137Cs in large terrestrial animals in Sweden | 251

Monitoring of
Cs-137 in Moose

Heby municipality
Start in 1986
~3700 samples
Gävle municipality
Start in 1986
~ 12 000 samples

My thesis

Two data sets on 137Csconcentrations in moose
from Heby (1986-2012)
and Gävle (1986-2008).
Paper 1:
descriptive
Paper 2:modelling withmultivariate statistics.
(PLS)

252 | Robert N. Weimer

Baltic Sea

Long-term Decline of Radiocaesium in Moose (Paper 1)
10000

Gävle 137Cs T1/2 eff =16 years

Bq kg-1 (f.w.)

1000

100

Heby 137Cs T1/2 eff= 16 years
10

Heby 134Cs T1/2 eff= 3 years
1

Year
Weimer et al., unpublished data

137Cs on average 18% higher in calves

compared to adults (Gävle)Bq kg-1 (f.w.)

10000

1000

100

Year

Weimer et al., unpublished data

4.3 Monitoring of 137Cs in large terrestrial animals in Sweden | 253

Model influence of various parameters* on 137Csconcentrations in moose by PLS (Paper 2)(* Environmental variables and physical characteristics)•

Heby annual mean variation in 1986-2012 was 68% (49-98%)•

Gävle annual mean variation in 1986-2008 was 53% (46-61%)

Weimer et al., unpublished data

Explanatory variables in PLS-models
1, Information from data set on:age, weight, sex, killing spot and date2, Supplementary information on:
Rainfall (mm) and temperature (°C) in June September
Deposition (Bq m-2) and habitat (%) around killingspots (Heby)254 | Robert N. Weimer

Heby area – 2 700 killing spots

PLS-model on Heby
data set

Deposition and time since deposition
Habitat type
Moose age
Weather conditions prior to hunting
seson

Weimer et al., unpublished data

4.3 Monitoring of 137Cs in large terrestrial animals in Sweden | 255

137Cs in Wild Boars in East-central Sweden,

2010-2014• ~170 muscle samples• High variation CV=162%• ex, 100 and 4900 Bq kg-1
,same date and place• Lowest levels in autumn
2 x BSc-thesis, Hallqvist, E. 2013 andFrtitzon, K. 2013

137Cs in Wild Boars 2010-2014

256 | Robert N. Weimer

137Cs in Bear and Lynx
An example from county of Västerbotten (Y)
Year
2010
2011

Bear (n)695±571 (9)553±423 (17)Range
90-202048-1280

Lynx (n)1369±1147 (2)910±1943 (11)Range
558-2180
90-6750

Brown bear

Lynx

MSc-thesis Chaiko, Y. 2012

Thanks for listening!
Questions ?

4.3 Monitoring of 137Cs in large terrestrial animals in Sweden | 257

4.4 Radiocaesium contamination in wild boars
Keitaro Tanoi†, 1† Presenter: uktanoi@mail.ecc.u-tokyo.ac.jp

1Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, JapanI present the distribution of radiocaesium in wild boars, as well as the official monitoring data of wildboars inspected in Fukushima Prefecture. After the Fukushima Daiichi nuclear power plant accident in 2011,
the radiocaesium contamination levels in wild boars in most of Fukushima Prefecture exceeded 100 Bq/kg,
which has been the limit for radioactivity in meat since April 2012 in Japan. The most contaminated wildboars were observed in Soso District, where the radiocaesium concentration in the soil was the highest in thewhole prefecture. To obtain detailed information on radiocaesium contamination in wild boars, we measured
radiocaesium concentrations in different organs and tissues from wild boars inhabiting Iitate Village in Soso
District in 2012 and 2013. After capturing the wild boars, we collected 24 organs and tissues and placed theminto vials. Using a NaI(Tl) scintillation counter, we determined the concentrations of radiocaesium (134Cs
and 137Cs) and found that the levels were highest in the muscles (approximately 15,000 Bq/kg) and lowest in
the ovaries (approximately 600 Bq/kg) in 2012, indicating large variation among the organs and tissues. The
trends were similar in 2012 and 2013. Observations of the contamination levels in wild boars revealed theradiocaesium availability in the forest and village ecosystems.

137Cs concentration (Bq kg-1)

Keywords: radioactive materials, radiocaesium, wild boars, Fukushima Daiichi nuclear power

Fig.1 Radiocaesium concentration in wild boar organs in November 2012.

258 | Keitaro Tanoi

Radiocesium contamination in wild boars
after the Fukushima daiichi NPP accident
Keitaro Tanoi

Wild boars in Fukushima
1. Introduction - Why wild boars?
2. Inspection data from Fukushima
3. Distribution of radiocesium in wildboars in 2012 and 2013
4. Summary
2

4.4 Radiocaesium contamination in wild boars | 259

Introduction•

Signiﬁcant quantities of radiocesium werereleased from Fukushima Daiichi NPP in
March 2011

• 70-80 % of Fukushima prefecture is
Forest.

Forest in Fukushima

3

Introduction• The dominantradionuclides in soil
are radiocesium 134
137
Cs and Cs.

• Very small amount ofradiostrontium(Steinhauser et al2013) and plutonium(Zheng et al .2012)were deposited in soil.

4

260 | Keitaro Tanoi

Introduction• Wild boars are…
• wild animals.
• vermin• omnivorous feeders.
• increasing in evacuated area
• need to be controlled by hunting in
5evacuated area.

2. Inspection data in Fukushima

6

4.4 Radiocaesium contamination in wild boars | 261

Location of Fukushima prefecture7

2. Inspection data in Fukushima

Figure. Inspection data of 137Cs
performed in Fukushima prefecture.
•••

Correlated with soil contamination
Highest: more than 50,000 bq/kg
Most of the samples have >100 Bq/kg
8262 | Keitaro Tanoi

3. Distribution of radiocesium in wild boars in 2012
and 2013

9

3. Distribution of radiocesium in wild boars in 2012
and 2013• Iitate-village• highlycontaminatedby the NPP
accident.

• all the inhabitant evacuate even after 4 years.
• need to reduce wild boars.
10

4.4 Radiocaesium contamination in wild boars | 263

3. Distribution of radiocesium in wild boars in 2012
and 2013

12

264 | Keitaro Tanoi

020121125-01
20121125-02
20121125-03
20121125-04
20121125-05
20121129-01
20121129-02

colon contens

muscle of fromt leg

tonguetonguemuscle of fromt leg

heart

heart

kidneystomachstomachmuscle of hind leg

small intestine

small intestine

kidneysmall intestine…

small intestine…

lungs

spleenlungs
spleen

liver

liver

brain

brain
colon

testistestisbladderpancreaspancreas

colon

blood

blood

bladderadrenal glands
ovary and uterus

adrenal glands

muscle of hind leg

7000

muscle of fromt leg

muscle of hind leg

kidneytongueheart

stomachsmall intestine

spleen

lungs

liver

bladdercolon

20131206-02

brain

20131206-01

5000

testis6000

pancreas

blood

4000

White: Juvenil, Gray: adultovary and uterus

20121125-01
20121125-02
20121125-03
20121125-04
20121125-05
20121129-01
20121129-02

adrenal glands

stomach contents

stomach contents

2013
thyroid gland0

thyroid gland

2000
bone

4000
ovary

6000

bone

8000

ovary

10000

stomach contents

Radiocesium (134Cs+137Cs)(Bq/kg)

3. Distribution of radiocesium in wild boars in 2012 and 2013
20000
18000
16000
14000
12000
10000
8000
6000
4000
2000
0
12000

thyroid gland2012

137Cs (Bq/kg)

137Cs(Bq/kg)

3. Distribution of radiocesium in wild boars in 2012

Figure: Radiocesium concentration of organs of wild boars in November 2012.
Data is shown as average of 5-7 wild boars captured in November of 2012.
13

Fig. 5

3000

2000

1000

14

4.4 Radiocaesium contamination in wild boars | 265

3. Distribution of radiocesium in wild boars in 2012
and 2013
Table The ratios of blood to muscle in 137Cs

ave.0.24

15

4. Summary• Monitoring the wild boars revealed that..
• The muscle, or meat, is highly

contaminated.

• The change of the radiocesium

situation in forest ecosystem.

• We need to have more data for years.
16

266 | Keitaro Tanoi

References

17

References
Coming	  soon	  !!	
  Agricultural	  Implica3ons	
  of	
  the	  Fukushima	
  Nuclear	
  Accident:	
  The	
  First	  Three	
  Years	  The First Three Years

18

4.4 Radiocaesium contamination in wild boars | 267

4.5 Wetland radioecology post-Chernobyl
and radiation doses to amphibians
Karolina Stark

Presenter: karolina.stark@su.se

Department of Ecology, Environment and Plant Sciences, Stockholm University

Wetland radioecology post-Chernobyl
and radiation doses to amphibians

Karolina Stark

karolina.stark@su.se

Stockholm University, Department of Ecology,
Environment, and Plant Sciences

137Cs fallout over Europe from the Chernobyl

accident in 1986

www.ssm.se
16/10/2015268 | Karolina Stark/Karolina Stark, Radioecology Workshop, Stockholm

Study sites

137Cs deposition (kBq/m2) in Sweden.

Air gammaspectrometry measurementsfrom SSM

Wetland ecosystems● ”Kidneys of the landscape”● Bogs = peat accumulating, no inflow/outflow

mires● Fens = peat accumulating, inflow● Swamps = mineral soil, with trees/shrubs● Marshes = mineral soil, emergent plants

4.5 Wetland radioecology post-Chernobyl and radiation doses to amphibians | 269

Factors influencing 137Cs accumulation in wetlands
FactorExampleMechanism ofretention

Reference

Type of soil

Peat or mineral soil

137Cs high affinity to clay

Sawhney, 1972; Broberg &Andersson, 1991; Avery,
1996

Degree of salinity

Marine or freshwater

Low salinity (saline
waters makes Cs+ moremobile)Horrill, 1984

Level of pH

High, neutral, lowHigh or neutral pH (H+releases Cs+ from soil
particles)

Munthe et al., 2001

Duration of saturation

Permanent or
temporary

Dry periods (constantly
saturated area loose
137Cs faster)Nylén & Grip, 1991;
Hilton et al., 1993;
Saxén, 1994

Topography

Elevated or low areas

Hollows/depression
enhance sedimentdeposition

Jeffries et al., 2002; Van
der Perk et al., 2002

Type of vegetation

Tall or short, thick or
scarceTall and thick vegetation
filter particles

Horrill, 1984; Mungur etal., 1995

Level of nutrients in soilHigh or low

High uptake of 137Cs byplants if low K+ andhigh NH4+

Camps et al., 2003

minerals

Modified from Stark et al., 2006. J of Environ Radioact 87: 175‐187● Wetland area in Utnora, Sweden● Alder forest swamp and a marsh dominated by reed
● Depositon >100 kBq/m2● Average inventory 1 MBq/m2 in wetland

270 | Karolina Stark

Results from 137Cs budget calculations
137Cs deposition

lake
outletstream

29 % of all 137Csfrom the lake
in 1986‐2002
was found in thewetlandAccumulation
occurred over
several years
flooding

17 kBq/m2
sedimented
on the stream banks
in 2003.
Counteracted by decay

The accumulation
prolongs the time thewetland will contain highactivity concentrations

From Stark et al., 2006. J of Environ Radioact 87: 175‐187

Radiation exposure assessment• New recommendations for radiation protection of theenvironment (animals and plants) increase the need tomeasure and estimate doses to biota in their specificenvironment.

• Estimating doses to biota has proved to be challenging(e.g. IAEA EMRAS I, II and IAEA MODARIA, STAR Network)• Assumptions in current biota dose models (e.g. ERICA
tool, RESRAD‐BIOTA) needs to be validated by fieldstudies taking biota ecology and physiology in toconsideration.

4.5 Wetland radioecology post-Chernobyl and radiation doses to amphibians | 271

Amphibians•

Amphibians can influence the energy and contaminant
dynamics within ecosystems (Seale, 1980; Beard et al., 2002)•

Key species in many wetlands, often having the greatest
abundance among vertebrates•

Amphibians are threatened world‐wide•

Protected in national legislation•

Amphibians may need special attention in manyenvironmental risk assessments for releases of contaminants
such as radionuclides

A frog’s physiology & ecology● Both aquatic &terrestrial stages● Complex life-cycle● Thin skin
● Hibernate where 137Cs

accumulates● Small home range

272 | Karolina Stark

● Constructed frog phantoms of PMMA containing

thermoluminescence (TL) chips

Measurement of dose to frog phantom

Measured dose for 90 days in 2003 and 2004
at site A and site B. 5 phantoms/year

5 cm

4.5 Wetland radioecology post-Chernobyl and radiation doses to amphibians | 273

Results:
External dose

● The measured doses were lower than thecalculated doses● Measured doses: 0.026 ± 0.003 mGy/d● Modelled dose range: 0.017-0.128 mGy/d

Measured external dose
0.004

2004
2003

Higher dose
measuredto the phantom
surface= frog skin

Dose rate (mGy/d)

0.00350.003

0.0025

0.002
0

1

2

3

4

Position•Phantoms provide valuable dose information forimprovement and verification of dose models
and in site‐specific assessments

274 | Karolina Stark• Workgroup exercise within IAEA’s Environmental Modellingfor Radiation Safety (EMRAS) II Programme

16/10/2015/Karolina Stark, Radioecology Workshop, Stockholm

4.5 Wetland radioecology post-Chernobyl and radiation doses to amphibians | 275

Assessment tools
Terrestrial

Freshwater

MarineStudy sites: Wetland swamps in temperate/sub‐tropicalregions

276 | Karolina Stark

Results
Terrestrial parameters

Results

Occupancy assumptions

Food choice

4.5 Wetland radioecology post-Chernobyl and radiation doses to amphibians | 277

Results

Assumed soil moisture
IAEA’s EMRAS II programme:
Radiation doses to hibernating frog in soil

Estimated and measured external radiation dose rates (µGy/h) from 137Cs to moor frog in Utnora
Swamp assuming 100% occupancy in soil. Measurements were done using frog phantoms(Stark and Pettersson, 2008).
16/10/2015278 | Karolina Stark/ Karolina Stark, Radioecology workshop, Stockholm

Thank you for your attention!

4.5 Wetland radioecology post-Chernobyl and radiation doses to amphibians | 279

4.6 Current conditions of the fisheries,
radioactive contamination of seafood, and fish ecology
on the fishing grounds of Fukushima
Tomoya Hori†,1, Takuji Noda1, Toshihiro Wada2, Takashi Iwasaki3,
Hiromichi Mitamura1, 5, Nobuaki Arai 4, 5
† Presenter: t-hori@bre.soc.i.kyoto-u.ac.jp

1 Graduate School of Informatics, Kyoto University, 606-8501 Kyoto, Japan

2 Institute of Environmental Radioactivity at Fukushima University, Fukushima, Fukushima 960-1296, Japan
3 Soma Branch, Fukushima Prefectural Fisheries Experimental Station, Soma, 976-0022 Fukushima, Japan
4 Field Science and Education and Research Center, Kyoto University, 606-8502 Kyoto, Japan
5 CREST, Japan Science and Technology Agency,332-0012 Saitama, Japan

After the Fukushima Daiichi Nuclear Power Plant accident, vast amounts of radionuclides were released
into the ocean. In April 2011, Fukushima prefecture began monitoring radioactive Cs concentrations in Fukushima’s marine products at the instruction of the Fukushima Prefectural Government (MAFF, 2015). The
radionuclide (134Cs and 137Cs) concentrations in marine species collected off the coast of Fukushima Prefecture were inspected. For three months after the accident, more than 50% of the specimens exceeded the Japanese regulatory limit for radioactive Cs (100 Bq/kg-wet). Subsequently, the overall radioactive Cs concentrations in marine products have decreased significantly. In the most recent tests, only 1% of the specimens
exceeded the limit, and no Cs was detected in more than 80% of the specimens (MAFF, 2015). Radioactive
Cs concentrations also differ greatly among taxa, habitats, and spatial distributions (Wada et al. 2013). This
report presents an example of fish ecology on fishing grounds contaminated by Cs. Since September 2013,
annual acoustic telemetry monitoring of the white spotted conger (Conger myriaster) has been conducted at
Matsukawa-ura, a brackish lagoon, in Fukushima, Japan, to elucidate their spatiotemporal distribution andactivities. The study showed that congers mainly inhabited areas with low Cs concentrations but that theysometimes spent time in other areas in which the sediments contained high levels of Cs contamination (106
to 3,773 Bq/kg dry, Fukushima Pref., 2014).
Keywords: Acoustic telemetry, Activity, Conger myriaster, radioactive contamination, fish ecology

280 | Tomoya Hori, Takuji Noda, Toshihiro Wada, Takashi Iwasaki, Hiromichi Mitamura1, 5, Nobuaki Arai

4.7 Role of trophic transfer in benthic
ecosystems off Fukushima
Clare Bradshaw

Presenter: clare.bradshaw@su.se

Department of Ecology, Environment and Plant Sciences Stockholm University

Role of trophic transfer in benthic
ecosystems off Fukushima
Clare Bradshaw
Dept. of Ecology, Environment and Plant Sciences
Stockholm University• Dose rates from 134+137Cs are highest in demersal fishwith sediment‐associated food chains and feeding
behaviours (Johansen et al 2015)• Demersal fish haveconsistently havehigher 137Csconcentrations ofthan pelagic ones
• Some species still
have highconcentrations
even 4 years after
the accident• Why?!
Wada et al (2013) JER 124: 246‐254

4.7 Role of trophic transfer in benthic ecosystems off Fukushima | 281

• Some benthic invertebrates
also have a slow decrease inCs‐137 concentrations• Is transfer to fish
through the benthic
food chain important?
Sohtome et al (2014) JER 138: 106‐115

Benthic foodweb structure
Most foodweb studies:
Benthic fish
Benthic invertebrates

Sediment (or organic
matter in sediment)

But what about meiofauna?
Benthic fish
Benthic macro‐invertebrates

Benthic meiofaunaorganic matter insediment

New project started July 2015!
sediment
Goals:
to understand how 137Cs is accumulated in marine benthic
meiofauna, and the role of this group of organisms as a source offood and Cs to higher trophic levels.
282 | Clare Bradshaw

Cruise on the Oshoro Maru
26 July – 10 August 2015
(University of Tokyo &Hokkaido University)

Benthic invertebrates

sediment

meiofauna !
Benthic fish

4.7 Role of trophic transfer in benthic ecosystems off Fukushima | 283

We will:• Analyse 137Cs concentrations in as many components ofthe food web as possible• Evaluate fish diet using gut content analysis (visual andwith DNA sequencing)• Evaluate meiofauna community composition using DNA
sequencing• Analyse stable isotope ratios (δ13C and δ15N) in as many
components of the food web as possible

This will:• Give us more detailed information about benthic foodweb structure, particularly the role of meiofauna• Allow us to better link food web structure to 137Csconcentrations

284 | Clare Bradshaw

4.8 Understanding consumer purchasing intentions towards
salted salmon produced in Miyagi prefecture, Japan
Takashi Suzuki†, 1, Taro Oishi 2, Hisashi Kurokura1, Nobuyuki Yagi1† Presenter: takashi-suzu1182@kss.biglobe.ne.jp

1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
2 Faculty of Socio-Environmental Studies, Fukuoka Institute of Technology, Higashi, Fukuoka, 811-0295 Japan.

After the Great East Japan Earthquake and Fukushima nuclear power plant accident in 2011, some newspapers said that consumers avoided purchasing fish products produced in the affected area because of concerns about radioactive contamination. However, consumers also bought fish products to contribute to thereconstruction of the affected area. Some previous research on agricultural products mentioned that consumers prefer to purchase products that have not only private dimensions but also public dimensions (e.g. environmental conservation, animal welfare, sustainable resource management, fair trade, and helping the local
economy). Thus, it is clear that consumer evaluations of a product differ according to the product’s dimensions. However, as there is limited research concerning fish products, the extent to which consumers’ concerns
about the radioactive contamination of fish products has had a negative on their purchasing intentions remains unclear. Thus, we sought to clarify the degree to which concerns about radioactive contamination had
negative effects on purchasing intentions by focusing on the salted salmon produced in Miyagi prefecture.
A factor analysis was conducted on data collected through an online survey targeted at consumers living inTokyo and Osaka in August 2012. Then, we clarified the effects of factors by applying structural equation
modelling based on the results of the factor analysis. The results of the factor analysis revealed four factors(F1: value of food, F2: concern about radioactive contamination, F3: purchasing intention along the private
dimension, F4: purchasing intention along the public dimension) related to consumer attitudes towards
Miyagi’s salted salmon, which we incorporated into a structural study (Fig. 1). The results of structural equation modelling indicated that the path coefficient between F1 and F3 and F4 was higher than that between
F2 and F3 and F4. Additionally, there was a significant difference between F2 and F3 by area. In Osaka, thenegative effect between F2 and F3 was significantly higher than the effect between F2 and F4. These results
indicate that advertising the public dimensions of fish products may be an effective way to reduce the negative effects between purchasing intentions and concern about radioactive contamination.
Keywords: consumer behavior, public dimension, Miyagi’s salted salmon, Great East Japan Earthquake,radioactive contamination of fish products
Value of food
(F1)

Tokyo :0.63***
Osaka:0.69***

Concern about
radioactive
contamination (F2)Tokyo :-0.26***
Osaka:-0.38***

Tokyo :0.60***
Osaka :0.67***

Purchase intention
for private attribute(F3)Tokyo :-0.19***
Osaka:-0.15**

Purchase intention
for public attribute(F4)

Goodness of fit
GFI:0.820 AGFI:0.765 RMSEA:0.061***：significant at.1% **：significant at.5%

Fig.1 Result of structural equation modeling by using SPSS Amos 20

4.8 Understanding consumer purchasing intentions towards salted salmon produced in Miyagi prefecture, Japan | 285

Understanding of the consumer ’s
consciousness for public aspects on
salted salmon produced in Miyagi
prefecture in JapanTa k a s h i S u z u k i 1 , Ta r o O i s h i 2 ,H i s a s h i k u r o k u r a 1 a n d N o b u y u k i Ya g i 1
1The

U n i v e r s i t y o f To k y o , 2 F u k u o k a I n s t i t u t e o f Te c h n o l o g y

Background：Great east Japan earthquake	

2	

Iwate	

Miyagi	

Fukushima	
©Kahoku-Shinpo	

Main affected area	
Severe affected area	

©TEPCO	

Huge damage for coastal area of north-east Japan286 | Takashi Suzuki, Taro Oishi, Hisashi Kurokura, Nobuyuki Yagi

Damage on fishery by nuclear disaster	

3	

Fukushima daiichi nuclear power plant accident	
・Contaminated water withradio cesium was leaked
to the sea→Fishery activity was suspended・Consumers avoid purchasing
fish produced in affected areas→Damage by bad image	©Yomiuri news paper (May 2012)	

Recovery of fishery activities are delayedby nuclear power plant accident and bad image
4	

Damage on fishery by bad image

Price decreasing of Miyagi’s farmed silver salmon 	
Price（Yen/Kg）	

Population exceeded
the standard	

600

6

500

5

400

4

300
200
100
0

3

The lowest
price(240 yen/kg)

2
1
02003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
yen/kgPopulation exceeded the standard(year)	

Even though silver salmon didn’t exceeded,
price decreased about 130 yen/kg by bad image©The Suisan-Keizai（August 2012）2011	

※No Production in

4.8 Understanding consumer purchasing intentions towards salted salmon produced in Miyagi prefecture, Japan | 287

Consumer’s altruistic behavior	

5	

＜Sales of antenna shop＞
・Iwate: 2 times
・Miyagi: 2.5 times
・Fukushima: 3 times(Compared to sales of April 2010)“This is the first time to visit thisshop, but I wish I would help
even a little by purchasing”©Nikkei news (May 2011)©Natural Essay (March 2012)	

Consumers purchase products produced inaffected area in order to contribute to reconstruction

Product’s public aspect	

6	

Product’s aspects of vegetable 	Excludable

Environmental
conservation

Rivalry	Contribution to
local industry

Private aspect	

Public aspect	

Codron et.al.(2006), Moser et al.(2011) and Ujiie(2013) 	

・Pay additional cost for product with public aspects

Tully and Winer(2013)

Public aspect is important on altruistic consumption
288 | Takashi Suzuki, Taro Oishi, Hisashi Kurokura, Nobuyuki Yagi

4.8 Understanding consumer purchasing intentions towards salted salmon produced in Miyagi prefecture, Japan | 289

9	

Questionnaire survey	
・Data collection :Online survey

Miyagi・Date of survey :August 2012
・Area :Tokyo and Osaka

Fukushima・Sample size :395 (Tokyo:210, Osaka:185)

Tokyo

Miyagi’s salted salmon

Osaka

・Market price was decreased
・Important product in Miyagi
Main affected area	
・Well-known by consumers
Severe affected area	
10	

Concern about radioactive contamination	
Tokyo	

Osaka	

9%5%

Miyagi

19%

47%

Fukushima

28%

45%

16%

Tokyo

9%

9%

13%

Concerned about all Japanese fish	

Osaka
Main affected area	
Severe affected area	

Concerned about affected area’s fish	
Concerned about Fukushima‘s fish
Concerned about all fish including imported ones	
Not concerned about fish sold in Japan	

290 | Takashi Suzuki, Taro Oishi, Hisashi Kurokura, Nobuyuki Yagi

11	

Example of Questions	
Example of questions （18 questions）	
・Miyagi's salted salmon tastes good	・It seems that Miyagi's salted salmon can be preserved for a
longtime because it is salted	
・By purchasing Miyagi's salted salmon, we contribute for thereconstruction of the affected areas	
・Having concerns about the inspective institutions onradioactivity of Miyagi's salmon	
・I want to buy Miyagi's salted salmon to consume at home	

Using five-point scale	
1Strongly
Agree
	

2
Agree

3
Indifferent

4
Disagree5Strongly
Disagree12	

Result：Factor analysis	
Detecting about consumers’ latent consciousness
Quality offood

Privateaspect

8 questions	

5 questions	Institution	

Concern
about
radioactivity
2 questions	

Method	Publicaspect	
3 questions	Online shop	
Consume at
home	




	

Prepared		

Taste	

Job creation
Reconstruction

Tradition	

Purchase intentions
4 factors on consumer consciousness
can be applied to structural equation modeling 	
4.8 Understanding consumer purchasing intentions towards salted salmon produced in Miyagi prefecture, Japan | 291

Result : Structural equation modeling
Value of foodTokyo :0.60
Osaka :0.67	

13	

Purchase intention
for private aspect

Tokyo :0.63
Osaka:0.69

Concern about
radioactive
contamination

Tokyo :-0.26
Osaka:-0.38	
Tokyo :-0.19
Osaka:-0.15	

Purchase intention
for public aspect<Goodness of fit> GFI:0.820 AGFI:0.765 RMSEA:0.061“Concern about silver salmon's radioactivity” doesn’t
have the strongest effects on purchase intention 	All path coefficients are significant at 5%

292 | Takashi Suzuki, Taro Oishi, Hisashi Kurokura, Nobuyuki Yagi

Discussion

16	

・Consumers place more importance on the values offood than concern on radioactivity 	Consumer’s rejection isn’t the main reason of pricedecreasing of salmon
・Negative effect differs by product’s aspects
Advertising public aspect of fish products can be
an effective way to reduce the negative effect ofradioactive contamination
Japanese consumers opted altruistic behaviorpurchasing products with public aspects	

4.8 Understanding consumer purchasing intentions towards salted salmon produced in Miyagi prefecture, Japan | 293

1177 	 Thank you for listening	

294 | Takashi Suzuki, Taro Oishi, Hisashi Kurokura, Nobuyuki Yagi

4.9 Long-term desorption kinetics of Csfrom contaminated soil
Kento Murota†,1, Takumi Saito1, 2† Presenter: kento.murota@nuclear.jp

1 School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8654, Japan

2 Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Ooaza Shirakata, Tokai, Naka, Ibaraki 319-1195, Japan.

Understanding the behaviour of caesium (Cs) in soils is crucial in the disposal of soil that is contaminatedby radiocaesium (137Cs). Cs is known to selectively adsorb to clay minerals in soils, and desorption of Cs fromsoils and clay minerals has received much research interest in recent decades. However, the Cs desorption has
typically been underestimated, which is particularly important for long-term management of contaminatedsoil. We investigated the long-term desorption kinetics of Cs from soil in the Fukushima prefecture via batch
desorption experiments in the presence of an adsorbent. The adsorbent can maintain a low concentration of
Cs in solution, and prevent re-adsorption of the desorbed Cs.
Up to 50% of 137Cs was desorbed after 139 days in 1-mM KCl, which was more than that desorbed via
ordinary short-term extraction using 1-M ammonium acetate. Furthermore, desorption of 137Cs continued
after this period. We also found that high concentrations of K+ prevented desorption of Cs in the initialstages of desorption, but that the effect decreased with time. The desorbed fraction of stable Cs (133Cs) was
less than that of 137Cs, which indicates that 137Cs can gradually move to more stable sites in the soil.
Keywords: Radiocaesium, stable caesium, soil, desorption, adsorbent, decontamination.

4.9 Long-term desorption kinetics of Cs from contaminated soil | 295

296 | Kento Murota, Takumi Saito

4.9 Long-term desorption kinetics of Cs from contaminated soil | 297

298 | Kento Murota, Takumi Saito

4.9 Long-term desorption kinetics of Cs from contaminated soil | 299

300 | Kento Murota, Takumi Saito

4.9 Long-term desorption kinetics of Cs from contaminated soil | 301

302 | Kento Murota, Takumi Saito

4.10 Interception and Storage of Wet Deposited
Radionuclides in Crops
Stefan B. Bengtsson

Presenter: stefan.bengtsson@me.com

Formerly at Swedish University of Agricultural Sciences and Fukushima University

Interception andStorage of Wet
DepositedRadionuclides in
Crops

Contents
 Introduction
 Background Aim
 Materials and Methods
 Results and Discussion
 Conclusions

4.10 Interception and Storage of Wet Deposited Radionuclides in Crops | 303

Introduction
 Release of radionuclides from accidents can result indeposition onto food crops.
 Main harmful radionuclides → radiocaesium (Cs), iodine(I) and radiostrontium (Sr)
 Level of interception is dependent on; 1) morphology, 2)angle of leaves, 3) plant biomass, and 4) water storage
capacity.
 Redistribution to edible plant parts depends on uptake.
 Information is essential for the risk assessment for foodchain.

Background Entrance of radionuclides into plants– Two main types of deposition: dry deposition and wet deposition– Uptake of radionuclides differs depending on: growth stage →well-developed stage, a majority are taken up.

 Interception of radionuclides− Complicated process → negatively charged leaves: weakerretention of monovalent ions than for divalent ions
− Related to plant morphology

304 | Stefan B. Bengtsson

Background

Cs+
−

−

−

−

−
−

−

−

−

−

− −

Sr2+
− −

Illustration with permission from Koranda & Robison (1978)

Background Uptake of radionuclides– Radionuclide entrance depends on: plant species, precipitation,
temperature, light, pH, carrier of the radionuclides, and valence ofthe radionuclides.
– Radionuclides are actively transported by the symplastic pathways
and by exchange mechanisms between phloem and xylem.

BBC (2013)4.10 Interception and Storage of Wet Deposited Radionuclides in Crops | 305

Background Distribution of radionuclides in plants– Radiostrontium, lower redistribution than radiocaesium– Epidermis retain more radiostrontium (divalent)– Caesium analog to potassium and strontium analog to calcium

 Transfer of radionuclides– Transfer is regulated by rate of foliar uptake and root uptake by plantparts.
– Concentration of radionuclides in plant is linearly related to theconcentration of radionuclides in the root zone of the soil.
– Described by a transfer factor (TF, m2 kg-1) or translocation factor(TLF, m2 kg-1), is explained later.

Aim Overall aim →306 | Stefan B. Bengtsson

to determine the amount ofradionuclides intercepted, taken up andredistributed to different plant parts
during wet deposition at different
growth stages of oilseed rape, wheat
and ley.

Aim The specific aims were:
1) Measure interception of 134Cs and 85Sr by oilseed rape,
wheat, and ley at different growth stages and clarify the
relation to plant biomass, leaf area, type of radionuclide
and type of crop (Papers I and III).
2) Investigate accumulation of 134Cs and 85Sr between plantparts of oilseed rape, wheat and ley at different growthstages and describe transfer to seeds and other plantparts through calculation of transfer factors (Papers II and
III) and translocation factors (Paper III).
3) Calculate distribution of 134Cs and 85Sr between plantparts of spring oilseed rape and spring wheat (Paper II).
4) Extend a trace element cycling model by including wet
deposited radionuclides with a description of interception
and foliar uptake for wheat (Paper IV).

Location of Uppsala

4.10 Interception and Storage of Wet Deposited Radionuclides in Crops | 307

Materials and Methods
 Study area
– Conducted at Ultuna– Two growing seasons
in 2010 and 2011Materials and Methods

308 | Stefan B. Bengtsson

Materials and Methods– The sowing in middle of May both years for spring oilseed rapeand spring wheat.
– The ley established in 2010 on bare soil.
– The ley was a mixture of grass (90%) and clovers (10%).
– Fertiliser rates were normal for the crops (nitrogene andphosporus).
– No potassium (K) was added

Materials and Methods− 134Cs was in the form as caesium
chloride and 85Sr was in the form
as strontium chloride− 1st year the amounts applied were;25-31 kBq m-2 for 134Cs and 29-50
kBq m-2 for 85Sr
− 2nd year the amounts applied
were; 40-41 kBq m-2 for 134Cs and85Sr

4.10 Interception and Storage of Wet Deposited Radionuclides in Crops | 309

310 | Stefan B. Bengtsson

Materials and Methods
 Calculations– Interception fraction (f) = activity in the standing plant directly after
deposition (Ai) divided total amount of activity deposited (At)– Transfer factor (TF) = activity in edible plant parts (Ac) divided total
amount of activity deposited (At)– Translocation factor (TLF) = activity in edible plant parts (Ac)divided activity intercepted at deposition (Ai)

Results and Discussion
 Interception (Paper I)− Depended on both biomass and leaf area
− Increased in relation to biomass for wheat and ley− Weaker relation for oilseed rape due to shedding of leaves andincrease of biomasss

4.10 Interception and Storage of Wet Deposited Radionuclides in Crops | 311

Results and Discussion
 Interception cont. (Paper I)− Increasing interception related to LAI for both
radionuclides− Although weaker relation for spring oilseed rape

Results and Discussion
 Activity concentration in ley (Paper III)

312 | Stefan B. Bengtsson

Results and Discussion
 Foliar uptake (Paper II)− TF-values used to estimate
uptake of radionuclides− TF-values had the same trend
as the activity concentration

Acknowledgements

To my supervisors!
••••

Assoc. Prof. Klas Rosén
Assoc. Prof. Jan Eriksson
Assoc. Prof. Annemieke Gärdenäs
Assoc. Prof. Mykhailo Vinichuk

4.10 Interception and Storage of Wet Deposited Radionuclides in Crops | 313

 Thesis can be found here:
http://pub.epsilon.slu.se/10855/1/bengtsson_s_131017.pdf
 Paper 1:
http://pub.epsilon.slu.se/9012/
 Paper 2:
http://pub.epsilon.slu.se/10789/2/bengtsson_et_al_130916.pdf
 Paper 3:
http://pub.epsilon.slu.se/11527/1/bengtsson_et_al_140929.pdf

314 | Stefan B. Bengtsson

4.11 Comparing Cs dynamics in two rice cultivars,
Milyang23 and Akihikari, by tracer experiments
Shuto Shiomi†,1, Tatsuya Nobori1, Natsuko I Kobayashi1, Keitaro Tanoi1, Tomoko M Nakanishi1† Presenter: nomanoma16@gmail.com

1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, JapanThe Fukushima Daiichi nuclear power plant accident occurred in 2011, resulting in the emission of ahuge amount of radioactive nuclides, subsequently contaminating farmlands in Fukushima. The rice plant(Oryza sativa L.), which is Japan’s main crop, was damaged by radiocesium (Cs-134 and Cs-137). Thus, we
explored breeding of a novel cultivar that accumulates less cesium in brown rice. Based on previous reports,
it was shown that Milyang 23 accumulates more cesium compared to Akihikari. Therefore, in this study, we
compared Milyang 23 and Akihikari in various growth stages to examine the differences in cesium concentrations, focusing on translocation that contributes to cesium accumulation. Phloem sap, which contains cesium, is transported from a source organ to a sink organ; thus, the primary measurement objects were brownrice during the harvesting stage and the youngest leaf (6th leaf ) during the juvenile stage. In brown rice, thecesium concentration was twice as high in Milyang as in Akihikari. In the 6th leaf, the result was similar tothat for brown rice. Conversely, in the 4th leaf blade, which transports phloem sap to the 6th leaf, levels in
Akihikari were higher than Milyang. These results suggest that Milyang transports more cesium than Akihikari by translocation.
Keywords: Fukushima Daiichi nuclear power plant accident, radiocesium, rice plant, translocation,
tracer experiment4.11 Comparing Cs dynamics in two rice cultivars, Milyang23 and Akihikari, by tracer experiments | 315

Comparing Cs dynamics in two ricecultivars, Milyang 23 and Akihikari,by tracer experiments.
Shuto Shiomi; Tatsuya Nobori; Natsuko I Kobayashi;
Keitaro Tanoi; Tomoko M Nakanishi
Graduate School of Agricultural and Life Sciences,
The University of Tokyo

Outline1. Background & Strategy
2. Tracer Experiments: Grown-up Rice Plant
3. Discussions
4. Tracer Experiment: Young Rice Plant
5. Conclusion

2316 | Shuto Shiomi, Tatsuya Nobori, Natsuko I Kobayashi, Keitaro Tanoi, Tomoko M Nakanishi（背景）Background: Contaminated Rice
Investigations of all rice inFukushima

Radiocesium accumulationin the brown riceYear

Total number

Over 100 Bq/kg

2012

10,345,207

71

2013

11,005,841

28

2014

11,004,552

2

Screening test
Detailed inspection

Under 100 Bq/kg

Over 100 Bq/kg

Shipping

Disposal（ Fukushima-no Megumi Anzen Taisaku Kyogikai webpage ）However, rice cropping is stillsuspended in some areas.
3

Background: Measures and Researches so far
At farmland• Potassium fertilization• Deep tillage

Genetics approach• Investigation of Cs uptake by root (e.g. AtHAK5)

Quantitative Trait Loci(QTL) analysis 	44.11 Comparing Cs dynamics in two rice cultivars, Milyang23 and Akihikari, by tracer experiments | 317

Strategy: QTL(Quantitative Trait Loci) analysis
Goal: Identifying genes contribute to quantitative trait
Process to the QTL analysis
1 . Cultivar selection
Necessary conditions for two cultivars① Inbred lines exist.
② Clear differences exist.
2. Phenotyping analysis
Using inbred lines
3. QTL analysis
Analyzing the results and mapping QTLStrategy: Cultivar Selection
Milyang 23 accumulates
much Cs in brown rice.
(Ishikawa, et al. 2009)

Milyang 23 is often used with
Akihikari as parental linesof the QTL analysis.
(e.g. Drought stress)

Are there any differencesof Cs dynamics between
Akihikari and Milyang ??

Akihikari	
  • Japonica	
  rice	• Origin： Japan	
• High	  yielding	• Early	
  maturing	

Milyang	
  23	
• Indica	
  rice	• Origin： Korea	
• High	  yielding	• Semidwarf	

Seeds of the rice

318 | Shuto Shiomi, Tatsuya Nobori, Natsuko I Kobayashi, Keitaro Tanoi, Tomoko M Nakanishi

6Objective

Finding out the differencesof Cs dynamics between
Milyang 23 and Akihikari（ Miyagi Prefectural Government Webpage）

Juvenile Stage

Experiment 1

Heading Stage

Harvesting Stage
7

Investigations in
the heading and the harvesting stages

137Cs: 9.0 kBq/L

K: 0.27 mM

Growing rice plant
In a growth chamber

Measuring 137Cs by an
NaI scintillation counter8

4.11 Comparing Cs dynamics in two rice cultivars, Milyang23 and Akihikari, by tracer experiments | 319

Milyang 23 accumulated much Cs in the ears
Heading stage
Graphradiocesium accumulation and distribution ofrice plants.
	

Milyang 23 accumulated much Cs in the brown rice
Harvesting stage
Graphradiocesium concentration of various tissues ofrice plants.
	

320 | Shuto Shiomi, Tatsuya Nobori, Natsuko I Kobayashi, Keitaro Tanoi, Tomoko M Nakanishi

Experiment 2

Cesium uptakes from the roots
were at the same level

Graphradiocesium concentration ofshoot and root of rice plants.
	

shoot
root

11

Focusing on Translocation＝

A sap flow in the phloem from the old organs to the young organs＝

Source organs＝

Experiment. 1

Sink organs

Experiment. 3?
?

Experiment. 2

12

4.11 Comparing Cs dynamics in two rice cultivars, Milyang23 and Akihikari, by tracer experiments | 321

Growth process

Experiment 3

Investigations in theJuvenile Stage

137Cs: 9.0 kBq/L

No RI

K: 0.27 mM

Measuring 137Cs by an
NaI scintillation counter

Measuring K by
an ICP-OES
14

322 | Shuto Shiomi, Tatsuya Nobori, Natsuko I Kobayashi, Keitaro Tanoi, Tomoko M Nakanishi

In K concentration, there was nodifference between the two cultivars
Juvenile stageGraph
potassium concentration of various leaves ofseedling rice plants.
	

Milyang 23 accumulated much Cs in the new leaves
Juvenile stage
Graphradiocesium concentration of various leaves ofseedling rice plants.
	

16

4.11 Comparing Cs dynamics in two rice cultivars, Milyang23 and Akihikari, by tracer experiments | 323

Conclusion

Cultivar selection

Phenotyping analysis

This research

Milyang 23 accumulated much Cs in・new leaves in the juvenile stage.
・ears in the heading stage.
・brown rice in the harvesting stage.

In progress

QTL analysis

Breeding new cultivars

Acknowledgements

Rice planting

Harvesting rice

324 | Shuto Shiomi, Tatsuya Nobori, Natsuko I Kobayashi, Keitaro Tanoi, Tomoko M Nakanishi

18

Tack för att ni lyssnade	

4.11 Comparing Cs dynamics in two rice cultivars, Milyang23 and Akihikari, by tracer experiments | 325

4.12 The characterisation of caesium accumulationin wild radish
Nanami Oshima†, 1, Maki Katsuhara2, Hiroaki Setoguchi1† Presenter: oshima.nanami.58x@st.kyoto-u.ac.jp

1 Faculty of Integrated Human Studies, Kyoto University, Yoshidanihonmatsu-cho, Sakyo-ku, Kyoto, 606-8501, Japan
2 Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan.

This study evaluated the characteristics of caesium accumulation in two ecotypes of Raphanus sativus L.
var. raphanistroides Makino (wild radish). Following the Fukushima Daiichi nuclear power plant accident,
radioactive caesium was dispersed across agricultural areas, especially in Fukushima Prefecture. Some of
the crops cultivated in these areas accumulated caesium, preventing their use for consumption. However,
the ability of these plants to accumulate caesium could be used for the phytoremediation of radiocaesium.
Wild radish was chosen because of its high caesium transfer factor. Two ecotypes of wild radish, coastal areaand freshwater lakeshore, were analysed to identify their tolerance of and ability to accumulate caesium.
They were grown in soils containing increasing caesium concentrations in order to determine the concentrations of caesium and potassium that induce plant death. In another experiment, plants were exposed tothree fixed concentrations of caesium solution for 16 days in order to evaluate the responses of the two ecotypes, and the levels of accumulation in the plant body, at each exposure concentration. The concentrationof caesium in vacuoles and vessels were also investigated to reveal the localisation of accumulated caesium.
Further studies to dissect the physiological and molecular mechanisms of caesium accumulation are needed
to develop effective phytoremediation with wild radish in real fields.
Keywords: Phytoremediation, caesium, wild radish, Fukushima Daiichi nuclear power plant accident

326 | Nanami Oshima, Maki Katsuhara, Hiroaki Setoguchi

The  analysis  of  characteriza1on  of  cesium  accumula1on  in  wild  radish	
Nanami	  Oshima	
  (Kyoto	
  University)	
  Maki	
  Katsuhara	
  (Okayama	
  University)	
  Hiroaki	  Setoguchi	
  (Kyoto	
  University)	

Kumagawa  area  in  Ohkuma  town	
Kumagawa	
  area	  in	
  Ohkuma	
  town	  is	
  located	
  	
  
3	
  Km	
  away	  from	  Fukushima	  Daiichi	
  Nuclear	
  Power	  Plants.	
Air	
  dose	  rate	  in	
  2013	
  :	
  20	
  μSv	  /	  h	  Annual	  exposed	
  dose	  in	
  2013	
  :	
  438	
  mSv	  	
  	

4.12 The characterisation of caesium accumulation in wild radish | 327

Kumagawa  area  in  Ohkuma  town	About	
  96%	  of	
  residen4al	
  area	  has	  been	  designated	
  to	
  “diﬃcult-­‐to-­‐return	
  zone”	
The	
  acPvity	
  of	
  cesium	  in	
  the	
  surface	
  of	
  the	
  soil:	
  
85.2	
  ±	
  6.10	
  Bq	
  /g	
  (CulPvaPon	
  depth	  =	
  5	
  cm,2013)	

Preliminary	
  experiment	
  for	  in	
  laboratory	  	
  Watering	
  only	  once	  with	
  5mM	
  cesium	
  chloride	
  (non	  radioac4ve)	
  	
  
and	
  culPvaPon	
  for	  60	  days	  (Setoguchi	  et	
  al,	
  unpublished)	
  	
Artemisia	
  fukudo	
  	
  
0.16	
  mg	
  Cs	
  /	
  kg	
  dw	
(Asteraceae) 	
  (coastal	
  plants,	
  halophyte)	
Arabidopsis	
  kamcha/ca 	
  
0.47	
  mg	
  Cs	
  /	
  kg	
  dw	
(coastal	
  and	
  	
  
	
  	
  	
  	
  	
  	
  	
  inland	
  ecotypes)	
Wild	
  radish	Raphanus	
  sa/vus 	  	

328 | Nanami Oshima, Maki Katsuhara, Hiroaki Setoguchi

1.96	
  mg	
  Cs	
  /	
  kg	
  dw	

The  Result  of  ﬁeld  experiment  for  two  and  half  a  month  in  Kumagawa  area  in  2013  (wild  radish  from  inland  area)	

Hou$uynia	
  cordata	
  :	
  0.329	  others	  	
  including	
  Poaceae	
  exhibited	
  0.060	
  or	
  less	  	  (	  Yamashita	  et	
  al,	  2014	
  )	
  

Wild	
  radish	
  showed	
  relaPvely	
  high	  transfer	
  factor	  value.	

Material  and  methods	

4.12 The characterisation of caesium accumulation in wild radish | 329

Wild  radish	l Raphanus	
  sa2vus	
  L.	
  var.	
  raphanistroides	
  Makino	  	  l	  Habitat	
  across	
  Japan,	  mainly	
  in	
  coastal	  area.	
  l	  Annual	
  plant	  Two  ecotypes  used  for  this  study	

Habitat	
Loca4on	
Coastal	Mie	  Pref.	
  (Matsunase	
  shore)	
Inland	 Shiga	  Pref.	
  	
  (Lake	
  Biwa)	
330 | Nanami Oshima, Maki Katsuhara, Hiroaki Setoguchi

Two  ecotypes  of  wild  radish	Diﬀerent	
  ecological	
  trait	  	
  (defense	
  mechanism)	
=	
  Prevent	
  plants	
  from	  taking	
  too	  much	  harmful	
  components	

Coastal	Inland	  		  	
  Seawater	
  	

Freshwater	  	The  objec1ve  	
Diﬀerent	
  mechanism	
  in	
  each	  type	CharacterisPcs	
  of	
  each	  type	  to	
  cesium	
  	
  
What	
  contributes	
  to	
  characteris4cs	
  and	  	
  from	
  which	  part	  this	  comes?	
  4.12 The characterisation of caesium accumulation in wild radish | 331

Diﬀerence  among  two  types  and  roots  and  leaves	
Coastal	  	Inland	

Leaves	What	
  contributes	
  to	
  characteris4cs	
  and	
  from	  which	  part?	
  Roots	

Methods  	Germina4on	
  	

Growth	  	
  Measurements	
  of	
  	
  
in	
  controlled	
  condi4on	
 cesium	
  and	
  potassium	
  	

Vermiculite	
FerPlizer	
  	

332 | Nanami Oshima, Maki Katsuhara, Hiroaki Setoguchi

Methods  	l	
  Cesium	
  chloride	
  (	
  Cs	
  133	  )	  soluPon	
  was	
  cultured	  with	
  each	  	
  replicate	
  acer	  two	
  foliage	
  appeared.	
  	
  Preliminary	
  experiments	  	
  Cultured	
  with	  	
  incremental	
  increase	  of	
  cesium	
  soluPon	
  (up	  to	
  30mM)	
  8	
  replicates	
  from	  each	  types	
  were	  cultured	
  with	  each	
  	
  	
  
5mM,	
  15mM,	
  25mM	  cesium	
  chloride	
  soluPon	
  every	
  3	
  days	  by	
  5mM	
  for	  16	  days	  .	
  	
  Dried	
  for	  72	  hours	
  and	
  crashed	
  and	
  mixed.	
  	
  0.1g	  from	  this	  were	
  dissolved	
  in	
  60	
  %	
  nitric	
  acid.	
  The	  concentraPon	
  of	
  cesium	  and	
  potassium	
  were	  measured	
  only	  once.	
  Results  and  discussion  	

4.12 The characterisation of caesium accumulation in wild radish | 333

Tolerance  to  high  cesium	

Preliminary  experiment  (24  replicates)	
8mM	
  (3	
  days)	
 20mM	  (16	  days)	
 30mM(29	
  days)	

Inland	  	Both	
  types	
  could	  survive	  under	
  30mM.	

Coastal	  	334 | Nanami Oshima, Maki Katsuhara, Hiroaki Setoguchi

Tolerance  to  cesium(5mM,  15mM,  25mM)  	Both	
  types	  have	  almost	
  the	
  same	  tolerance	
  to	
  cesium	

5mM	

15mM	

25mM	

Inland	  	7	
  have	  died	2	
  have	  died	
Coastal	  	5	
  have	  died	1	
  has	  died	Diﬀerence  among  two  types  and  roots  and  leaves	
Coastal	  	Inland	

Leaves	
Roots	What	
  contributes	
  to	
  characteris4cs	
  and	  	
  from	
  which	  part?	
  4.12 The characterisation of caesium accumulation in wild radish | 335

Cesium/potassium  ra1o  in  roots  and  leaves	
Cesium	  selec4vity	
  in	
  leaves?	
  	

Coastal	Inland	

20	
  

20	
  

15	
  

15	
  

10	
  

10	
  

5	
  

5	
  

0	
  

0	
  
5mM	
  

15mM	
  

Roots	
  

25mM	
  

5mM	
  

15mM	
  

Roots	  Leaves	
  

25mM	
  

Leaves	
  Diﬀerence  among  two  types  and  roots  and  leaves	
Coastal	  	Inland	

Leaves	
Roots	What	
  contributes	
  to	
  characteris4cs	
  and	  	
  from	
  which	  part?	
  336 | Nanami Oshima, Maki Katsuhara, Hiroaki Setoguchi

Cesium  concentra1on  in  leaves  and  roots	

900.0	  	
  Roots	

	
  Defense	
  mechanism	
  ?	

800.0	  	
  700.0	  	
  600.0	  	
  500.0	  	
  400.0	  	
  300.0	  	
  200.0	  	
  100.0	  	
  Cesium	  concentraPon	
  (ppb)	

Cesium	  concentraPon	
  (ppb)	

1000.0	  	
  Leaves	1000.0	  	
  900.0	  	
  800.0	  	
  700.0	  	
  600.0	  	
  500.0	  	
  400.0	  	
  300.0	  	
  200.0	  	
  100.0	
  	
  
0.0	
  	
  

0.0	
  	
  

5mM	
  

15mM	
  

Coastal	
  

25mM	
  

Inland	
  

5mM	
  

15mM	
   25mM	
  Coastal	
  Inland	  Summary    	Coastal	  	
Leaves	Ecological	
  trait	
  (defense	
  mechanism)?	

Cesium	  selec4vity	
  ?	

Roots	

Inland		
  Diﬀerent	
  tendency	
  	

Nearly	  the	
  same	  tendency	

4.12 The characterisation of caesium accumulation in wild radish | 337

Discussion  	

Coastal	  	Inland	  	Ecological	
  trait	  (defense	
  mechanism)	

Accumula4on	
  (Accumulate	
  more	  cesium	  as	
  concentraPon	
  increases	
  in	
  leaves)	

Tolerance	
Selec4vity	
  	In	
  leaves	

○	
 ×	

×	

○	

○	

×	

Almost	  the	
  same	  	Further  research	l	
  InvesPgate	
  the	
  eﬀect	
  of	
  characterisPcs	
  on	
  cesium	  uptake	
  and	
  accumulaPon	
  	
  
l	
  Plants	
  are	
  grown	
  under	  low	  concentraPon	
  of	
  cesium	
  soluPon	
  to	
  invesPgate	
  their	
  aﬃnity	  to	
  cesium.	
  l	  Measure	
  the	  concentraPon	
  of	
  cesium	
  in	
  	
  
vacuoles	  in	
  leaves.	
  
	
  
	
  
	
338 | Nanami Oshima, Maki Katsuhara, Hiroaki SetoguchiAcknowledgement  	Ms.	
  Sanae	
  Rikiishi	
  (Okayama	
  University)	
  
All	
  of	
  Setoguchi	
  laboratory	
  members	
  	
  
	
  	
  	
  	
  

4.12 The characterisation of caesium accumulation in wild radish | 339

4.13 The impact of potassium fertilisation:
Investigation using a radioisotope tracer experiment
Natsuko I. Kobayashi†, v, Ryohei Sugita1, Tatsuya Nobori1, 2, Ryosuke Ito1,
Keitaro Tanoi1, Tomoko M. Nakanishi1† Presenter: anikoba@mail.ecc.u-tokyo.ac.jp

1 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
2 Present address; Max Planck Institute for Plant Breeding Research, Köln, Germany

To ensure the reduction of radiocesium contamination in agricultural products, it is important to define
the factors affecting radiocesium behaviour in a living plant. For rice, survey data collected from various
paddy fields in Fukushima clearly demonstrated that soil potassium (K) content is negatively correlated withradiocesium content in rice plants, resulting in the encouragement of K fertilisation. However, the scientificbasis for the effect of K supply on radiocesium uptake and transport remains unclear. Therefore, we performed Cs-137 tracer experiments to investigate the physiological effect of K supply on radiocesium uptake
and movement. When rice plants were grown in solution containing 3 mM K for 8 weeks, Cs-137 content
in shoots was reduced to less than half of that grown under K deficient conditions. We also found that theamount of Cs-137 transferred from old to new leaves and ears was significantly decreased by supplying K in
the solution. As a result, Cs-137 content in the grain was reduced to one-sixth in the presence of K. These effects of K fertilisation could be generally explained by the similar movement of K and Cs in plants, as well as
by competition between K and Cs ions during the root uptake process. In this context, we performed several
tracer experiments to clearly demonstrate the similarities and differences between the behaviours of the twoions. Our results increased our understanding of the physiological characteristics of radiocesium in plants,
which can be used for the development of robust measures in agricultural fields.
Keywords: Tracer, potassium fertilisation, rice, uptake, transport

340 | Natsuko I. Kobayashi, v, Ryohei Sugita, Tatsuya Nobori, Ryosuke Ito, Keitaro Tanoi, Tomoko M. Nakanishi

4.13 The impact of potassium fertilisation: Investigation using a radioisotope tracer experiment | 341

342 | Natsuko I. Kobayashi, v, Ryohei Sugita, Tatsuya Nobori, Ryosuke Ito, Keitaro Tanoi, Tomoko M. Nakanishi

4.13 The impact of potassium fertilisation: Investigation using a radioisotope tracer experiment | 343

344 | Natsuko I. Kobayashi, v, Ryohei Sugita, Tatsuya Nobori, Ryosuke Ito, Keitaro Tanoi, Tomoko M. Nakanishi

4.13 The impact of potassium fertilisation: Investigation using a radioisotope tracer experiment | 345

346 | Natsuko I. Kobayashi, v, Ryohei Sugita, Tatsuya Nobori, Ryosuke Ito, Keitaro Tanoi, Tomoko M. Nakanishi

4.13 The impact of potassium fertilisation: Investigation using a radioisotope tracer experiment | 347

4.14 Really long term radiological assessmentof ecosystems and humans
Ulrik Kautsky

Presenter: ulrik.kautsky@skb.se

Swedish Nuclear Fuel and Waste Management Company (SKB)

348 | Ulrik Kautsky

4.14 Really long term radiological assessment of ecosystems and humans | 349

350 | Ulrik Kautsky

4.14 Really long term radiological assessment of ecosystems and humans | 351

352 | Ulrik Kautsky

4.14 Really long term radiological assessment of ecosystems and humans | 353

354 | Ulrik Kautsky

4.14 Really long term radiological assessment of ecosystems and humans | 355

356 | Ulrik Kautsky

4.14 Really long term radiological assessment of ecosystems and humans | 357

358 | Ulrik Kautsky

4.14 Really long term radiological assessment of ecosystems and humans | 359

360 | Ulrik Kautsky

4.14 Really long term radiological assessment of ecosystems and humans | 361

362 | Ulrik Kautsky

4.14 Really long term radiological assessment of ecosystems and humans | 363

4.15 Visit to Forsmark
Orientation for visiting the final repository for radioactive operational waste and the ecosystem monitoring sites for the proposed deep repository for nuclear waste at Forsmark operated by SKB, Swedish Nuclear
Fuel and Waste Management Co.
See the photographs record of Day 4 on 4 Sep 2015 in Chapter 6.

Programme
2015-09-04

10:00

Arrival at Forsmark.

10:00

Presentation of SKB Forsmark.

11:00

Check-in at SFR.
Passport- and security control.

11:15

Guided tour exhibition underground.

12:30

Lunch at Forsmark’s Inn.

13:30

Out in the field with Sara Nordén – site investigations
for the proposed deep repository for nuclear waste.
We will visit a range of different ecosystems in the area.

16:00

Departure.

364 | Sweden-Japan Radioecology Workshop for Students, 2015

Important information when visiting our facility
Visitor services at our facilities are an important part of the comprehensive work we put into informing the
public about the management of Sweden’s nuclear waste. Regarding the visit, please find some important
information below.

Final repository for radioactive operational waste, SFR
Active side (approx. 2 hours)
The visit starts with information about the facility. This is followed by a guided tour underground, down
to a depth of 50 metres. SKB’s own bus will be used for the underground tour. Please note that the tour
includes a 400 metres long walk underground in steep slopes and stairs.
Minimum age: 18 years.
For the safety of each visitor the following regulations must be attended when visiting our facilities:
・ Each person has to be able to walk without support in SFR. Therefore, no wheel chairs, walkers,
crutches or sticks are permitted underground.
・ Alcohol may not be consumed before or during the visit.
・ We recommend comfortable shoes and casual clothing.
・ We do not allow visitors to bring cameras, cell phones or bags during the visit in SFR-facility.
It is incumbent on the group leader to pass this information on to all participants.
According to unpredictable activities in our facilities, we reserve ourselves the right of changing the
programme or if necessary cancel the visit.

Those who, after considering the above, choose to abstain from the tour are welcome to contact us todiscuss how we, in an alternative way, can provide required information.

Kind regards,
Svensk Kärnbränslehantering AB(Swedish Nuclear Fuel and Waste Management Co.)
Visitor’s administration
Telephone: +46 173 883 00
Email: linda.bergman@skb.se

Chapter 4

Workshop at Stockholm University | 365

Chapter 5
Student Reports

5.1 Attending the Japan-Sweden workshop
Nobuko Mitsuoka

Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

1. Introduction
As a researcher studying the impact of the Fukushima nuclear power plant accident, I was also very interested in the impact of the Chernobyl accident on agriculture. I have read many studies related to the Chernobyl accident in an attempt to gain more knowledge that could enhance my own research. Although thescale and location of the accident differ between Fukushima and Chernobyl, in my opinion there are many
similarities, and a significant body of scientific knowledge has accumulated as a result of the Chernobyl accident from which the Japanese can greatly benefit. Thus, I wanted to attend the workshop and hear the stories
of researchers who were leading experts during the Chernobyl accident. Besides my interest in the accidentsite and studies on the area, an additional motivation for me to attend the workshop was to improve my scientific communication skills. Since I had never given a presentation in English at an international workshop
or academic meeting, I wished to gain such experience.
I was originally interested in heavy metal contamination of soil and wrote my senior thesis on the topic.
I was in my senior year of undergraduate studies when the Great East Japan Earthquake happened. I was
studying abroad in the US at the time and did not experience the earthquake directly. However, it was extremely shocking news for me and I was very concerned about its impacts. After the earthquake, next camethe Fukushima Daiichi Nuclear Power Plant accident. This was such a devastating event, and I could not believe the response of the Japanese government. When I returned to Japan in May 2011, the country was still
experiencing the aftermath of the disaster. Shipment of most of the agricultural products from Fukushima
was suspended. Even after the ban was lifted for certain products, people did not want to buy them becauseof harmful rumours. At this time, I felt the urgent need for scientific evidence and communication with thegeneral public to get rid of the negative image of agricultural products from Fukushima. Before the nuclear
accident, Fukushima was renowned as a rich agricultural area. I hoped to contribute to the restoration of
Fukushima’s image as a major agricultural area using my scientific knowledge on soil contamination. For thisreason, I chose to study soil caesium contamination and its phyto-availability.
Some of my findings were reported at the Fukushima Contamination Commission by my professor; with
this, I felt that I was partly able to contribute to the restoration of Fukushima’s reputation. Attending theworkshop was also a wonderful opportunity for scientific communication, allowing me to present the latest
research on Fukushima to people from another country, and furthering understanding in this field of study.

2. What I felt in Sweden
2-1. Impressions after attending the workshop

This was my first presentation in English at an official event, and so I felt very nervous before attending
the workshop. However, it turned out to be an excellent opportunity for scientific communication. Although

368 | Sweden-Japan Radioecology Workshop for Students, 2015

my English skills are not perfect and there are many areas in which I can improve, several of the Swedish
students and professors showed interest in and praised my presentation. I also received constructive feedback
for future improvement.
All of the presentations were extremely interesting and I gained considerable new insights into the fieldof radioecology. I found the case of pit lakes particularly interesting. In the first instance, I had never heardof pit lakes and the problems connected with radioactive contamination. Although some lakes can containa certain amount of uranium-related radioactive material, even if they are not uranium mining sites, it surprised me to learn that, without knowing this fact, some people spend their holidays and swim in those lakes.
I thought that it would be an important research topic to create a distribution map of radioactivity levels inpit lakes across Sweden.
It was also interesting to learn more about events at the time of the Chernobyl accident. Since I was notvery familiar with Sweden or its geography, I did not know how close Sweden was to Chernobyl and theextent of the effects of the accident in the country. There are many similarities between Japan and Sweden. I
wish we had known about the knowledge accumulated by the Swedes as this could have helped us to respond
more rapidly to the Fukushima accident.

2-2. Swedish nuclear waste management site

In my opinion, nuclear power plants are currently necessary in Japan because of the problems of thermal
power plants, such as their high CO2 emissions and the limited reserves of fossil fuels. Ideally, we would gradually shift to renewable energy to ensure sustainable energy production to protect the futures of both people
and nature. However, for now, it is extremely difficult to cover Japan’s energy needs with renewable energy;
therefore, in my opinion, nuclear power plants should resume operation in Japan. The largest challenge is
how to manage nuclear waste. This has been the topic of long discussion in Japan, and remains unresolved. In
Sweden, the discussion has been ongoing since before 1970, and studies to determine suitable waste management sites and procedures have been carried out since that time. It is astonishing to me to learn that Sweden
has had to deal with this issue for such a long time, and has a thorough plan for nuclear waste management
for nuclear power plants in operation throughout the country. In my opinion, there are many useful things
that Japan can learn from Swedish nuclear management planning.

1-3 Food, nature and people in Sweden
1-3-1 Food in Sweden
As I expected from my preconceptions of Northern Europe, I had many opportunities to eat salmon!
Although I ate salmon almost every day, I never became tired of it because it was so delicious! At the reception event at Gothenburg University, people from the university treated us to large amounts of seafood,including salmon, shrimp, and crayfish. There were three varieties of salmon; smoked, fermented, and grilled.
It was surprising for me to see people eating fermented fish; however, really, it was not that bad at all! The
most shocking food I ate during my stay was “surströmming” which we were introduced to by professors at
Stockholm University. Surströmming is known as “the stinkiest food in the world.” The smell was hundredsof times worse than I had imagined, and some of us had to rush into the toilet to get rid of the smell. It was
an interesting cultural experience, but I would not like to eat it again….
1-3-2 Nature in Sweden
We experienced Swedish nature through excursions on the second day at Gothenburg University and thefifth day in Forsmark. The birch and cedar forests were somewhat similar to those in Japan, such as in Nagano
Chapter 5

Student Reports | 369

or Hokkaido. There were also many Japanese species in the botanical garden at Gothenburg University. However, some parts were very different from Japan, and I got to experience true Scandinavian nature. Enormous
mushrooms and berries (lingonberries and blueberries) could be found everywhere. It felt very comfortable
walking in the deep forest feeling softly piled soil underneath my feet. Walking through Swedish nature wasone of the experiences that made the greatest impression during my visit.
1-3-3 People in Sweden
I was extremely impressed by the excellent English skills of Swedish people. I talked to many people in
Sweden including taxi drivers, shop assistants, and restaurant staff, and had no problems at all communicating with them in English. Everybody seems to understand and speak English very fluently with perfect pronunciation. I asked one Swedish person, “How come you speak English so well?” He answered that they havebeen watching English language television programs with subtitles since their childhood and that English is
deeply rooted to their lives. I was envious of Swedish people for having such an environment and I wish thatJapan could be like that. I also found Swedish people were very helpful, polite and humble. I asked the way
several times when I got lost in the city and everyone gave me directions in a very polite way. Some Japanesepeople would just say, “I don’t know” if they were asked directions by a foreigner, but everyone in Sweden
responded to me politely, despite the fact that I was from another country. I became a big fan of Sweden andits people, and I hope to visit the country again in the near future.

3. Summary
I would like to express my immense gratitude to the NPO group and professors from all of the participating universities for providing me with the opportunity for such a wonderful and memorable experience. Thiswas my first time visiting a European country and I was excited and nervous at the same time to be travellingaround with people I had never met before and to give a presentation in English in a foreign country. However, it turned out to be an incredible experience. Everything I saw in Sweden was beautiful, and the people
were lovely. The workshop and fieldtrip were extremely interesting and I learned a lot about nuclear power
plants and radioactivity. I am sure that knowing that so many people in Sweden are still conducting research
after Chernobyl will motivate me to deepen my research and to publish the outcomes for people who are
waiting for the most up-to-date results. I plan to build upon the experience and knowledge that I gained in
Sweden during my future research.

370 | Sweden-Japan Radioecology Workshop for Students, 2015

5.2 My first workshop on radioecology
Kyoko Ichikawa

Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

1. Introduction
At the time of the Great East Japan earthquake, I was visiting a pear (Pyrus spp. L.) orchard about 7 km
from the Fukushima Daiichi Nuclear Power Plant, and the farmers and I evacuated to the safety of a peach
farmer’s house. In response to this experience, I decided to study the effects of radiocesium contamination onpeach production. Therefore, the workshop described below was a good opportunity for me.
I was concerned that only a few people would participate in a workshop that focused on the Fukushima
Nuclear Power Plant accident, because I thought that the effects of radioactivity on agriculture were little
studied. I did not know other students who studied the Fukushima incident, but I looked forward to meetingthem.

2. Main section
2-1. Swedish researchers

Scientists from the University of Gothenburg and Stockholm University participated in this workshop.
Several researchers from the University of Gothenburg had previously studied the Chernobyl nuclear accident. The University of Gothenburg provided both experienced participants and a hospital. It was, however,difficult for me to understand their very technical scientific reports. Based on their experience with the Chernobyl accident, I felt that Swedish citizens might be more inclined than Japanese to take the issue of nuclear
safety seriously. The Chernobyl accident was the first catastrophic nuclear power plant accident, and its scale
was even greater than that of the Fukushima accident. I was interested in reports of the effects of using ‘thewhole body counter’ rather than the effects on a particular species or area of residence.
Because there were many biological presentations, I was interested in the seminar at Stockholm University.
The Swedish presentations of results from studies
of wild animals such as reindeer and moose wereinteresting.

2-2. Japanese researchers

The aim of this workshop was for Japanese
students to experience Swedish culture and learn
more about radioecology. It also gave me the opportunity to meet Japanese students who werestudying the Fukushima accident. The group in
my laboratory was relatively small, and I felt particularly motivated to stay with them during theChapter 5

Student Reports | 371

workshop. It was a good opportunity to discuss ourresearch and share ideas. I will keep in touch withthe workshop participants in the future.

2-3. Swedish ecology

Visiting the forest near the Forsmark nuclear
power plant was particularly interesting. It was
my first opportunity to enter a near-virgin forest.
I thought the difference between Japan and Sweden was related to the ice age. Most forests in Japanare located in a temperate zone, with many typesof deciduous trees. Fallen leaves litter the groundand contribute to increasing the soil organic matter
content. In addition, the numerous volcanoes in Japan have produced a class of soil that contains volcanic ash. Swedish forests contain large rocks fromthe ice age. As most of Sweden is located in a frigid
zone, the country has many coniferous trees, andthe breakdown of organic waste in the soil is slower
than that in Japan.
I was surprised that many berries grow on the moss found on the rocks (picture). Berries make fruits injust one year, despite their shallow roots and the heavy snow in winter. It seems that moss growing near the
Fukushima nuclear plant should readily absorb radiocesium. I concluded that the radiocesium concentration
in berries was higher because they grow on moss. The minimum acceptable level of radiation in food grownin the wild was increased from 300 Bq/kg to 1500 Bq/kg in Sweden.

3. Summary
I was near the Fukushima Daiichi Nuclear Power Plant at the time of the catastrophic earthquake at
nearby Tohuku. Thereafter, I participated in a workshop in Sweden, the home of scientists who had studied
the Chernobyl nuclear accident. I met many scientists and students who shared my interests. I have studied
the different approaches taken by scientists from Japan and Sweden following their respective nuclear power
plant accidents. I enjoyed learning about Swedish ecology. The workshop facilitated contact with other young
scientists studying the Fukushima accident.

372 | Sweden-Japan Radioecology Workshop for Students, 2015

5.3 A wonderful experience in Sweden
Osamu Hashimoto

Master course, Graduate School of Agricultual and Life science, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

1. Introduction
First, I would like to explain why I am studying the radioactive materials emitted from Fukushima Daiichi Nuclear Power Plant (FDNPP). My hometown is Koriyama City, Fukushima Prefecture, located 50 km
west-northwest from the FDNPP, so my hometown lies within the zone affected by radioactivity from theaccident. As everyone knows, high radiation doses cause serious damage to human health, and no one wants
to live under such circumstances. Those people who decided to leave Fukushima have been gradually moving
to other prefectures, and the people who decided to stay in Fukushima need support. I wish to help thesepeople, including my family, and this is why I study radioactive materials.
I study the absorption and translocation of radioactive caesium by roots from soils. However, I found thatthe more I studied this topic, the more I also needed knowledge of other subject areas. To have a thoroughunderstanding of my study topic, I need a broad knowledge of other related study areas. For me, this workshop was very appealing because I could learn a lot about both Fukushima and Sweden based on the impactsof Chernobyl. The information on Sweden was particularly interesting for me. It is easy for me to obtain
information on Fukushima, but I cannot easily learn about Sweden. Thus, I decided to participate in thisworkshop because I thought it was an excellent opportunity.

2. The experience in Sweden
2-1 Difficulty of communication

The main difficulty I faced was in communicating in English. It was particularly difficult to talk with
Swedish researchers about my study, despite the fact that it was my major. I had felt confident in my English
skills, but I realised that I had been wrong! When I travelled overseas in the past, I had no problems with
communication. This, I realised, was because the context was informal, and it was not necessary to speak correct English. However, when I wanted to explain about my study, I felt that I needed to speak correct, clear
English. I found even conversations about my research difficult, so it was natural that my presentation felt
like somewhat of a failure. I was unable explain myself clearly, and this felt extremely frustrating.

2-2 The presentations by other Japanese students

All of the presentations by the other Japanese students were excellent, and no one seemed to have problems
with their English, except me. The topics were very interesting, and I enjoyed the presentations. But when
they finished their presentations, the students seemed to have various regrets about them. I was surprised tosee their obvious desire to improve their skills. I experienced problems in speaking English, but other students tried to raise their English, presentation, and other skills. This experience served as motivation for me.

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2-3 The presentations by Swedish researchers

The presentations by Swedish researchers provided me with motivation from an academic point of view. I
found it surprising that they focused on naturally occurring radioactive materials in the natural environment.
I had thought that the quantities of these radioactive materials were so small that their effects could be ignored. However, in some areas in Sweden, higher levels of radioactive materials occur in the natural environment than we tend to be aware of, so I realised the importance of considering their effects.
At the end of the workshop we were asked, “How can we recruit new students? Most Swedish people haveforgotten the Chernobyl accident, and they don’t pay any attention to radioactivity.” This question made quite
an impression on me, and I realised that Japanese people will also gradually forget the FDNPP accident. If
we completely forget the accident, a similar disaster could be repeated in the future. It may be necessary tomaintain people’s interest, but how do we do that? I do not have any immediate answers to this question. If
we continue to study the FDNPP accident, we will eventually have to face this question, and at some pointin the future, we will need to find the answer.

3. Summary
By participating in this workshop, I was able to obtain significant knowledge about radioactivity. I found
all of the presentations very interesting, and each one taught me something new. I was very pleased to haveattended the workshop. I was left with two main impressions. One was my awareness of my poor English
skills. Other students had competent English skills, but I was unable to speak to Swedish people with fluency, and I found I was unable to present my study as I would have liked, which I found very frustrating. The
other point was realising the fact that people gradually forget such terrible accidents and perhaps becomecomplacent over time. I feel that this is a serious problem and a difficult one to address. Swedish people have
faced this problem with Chernobyl. I find myself asking when the Japanese will also face the same problem
and how will we address it.
These new perspectives and the added motivation the experience gave me make me feel so grateful to havebeen able to participate in this workshop, and I know I will draw on my experience in Sweden in my researchin the future.

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5.4 What I learned at the Japan–Sweden workshop
Momo Takada

Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1,Kagamiyama, Higashi-hiroshima,
Hiroshima 739-8521, Japan

1. Introduction
The purpose of the Japan-Sweden workshop was to learn about cutting-edge radioecology research andemergency preparedness for radiation disasters in Europe.
I study radiocaesium dynamics in forest soils, focusing on the temporal variation and spatial heterogeneity.
I first learned about the academic discipline “radioecology” after the Fukushima nuclear power plant accident
about 4 years ago. I also knew that radioecology evolved in northern European countries, including Sweden,
where it has been studied since the Chernobyl nuclear power plant accident, which occurred 30 years ago.
Therefore, I expected radioecology in Sweden to be 25 years ahead of studies in Japan.
I am interested in the social responses to the Chernobyl accident in Europe. I also wanted to learn about
the emergency preparedness of European countries for future radiation disasters. Few Japanese expected the
Fukushima accident after the Great East Japan Earthquake in 2011 and the accident lead to great confusion.
As Sweden experienced the Chernobyl accident about 30 years ago, I wanted to learn about the current situation in Sweden regarding future accidents.

2. Radioecology in Sweden and Japan
2-1. University of Gothenburg, Stockholm University

We heard about actual experiences following the Chernobyl accident, including details of the accident,
environmental measurements, the detection of radioactive materials, and surprise at the results. I found thetalks interesting because my university professors also spoke about their experiences following the Fukushima accident, which were similar to the experiences associated with the Chernobyl accident. I postulated
that a series of steps always follows a nuclear accident, i.e. the accident itself, measurements, detection, andsurprise. Various studies related to radioecology have been conducted. I wanted to learn more about studies
on radiocaesium dynamics in forest ecosystems.
I heard several presentations about the temporal changes in radioactivity in wild animals. I learned that themost effective measure to protect humans and society from radiation is to control the amount of radionuclide
intake in food. Therefore, food monitoring is important and has long been conducted. In Japan, radioactive
materials are dealt with as special substances. In Sweden, radioactive materials produced by the Chernobyl
accident are dealt with as an environmental pollutant, like heavy metals.
The University of Gothenburg has a course on emergency preparedness. This interested me, so I asked a
PhD student about the course content. Possible emergency situations are accidents occurring at industrial
nuclear facilities, including nuclear power plants. Preparedness involves preparing equipment for measuring
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ment of human resources for emergencies should be enhanced. However, researchers may not contributemuch to emergency preparedness.

2-2. Studies of Japanese students and my presentation

The conference represented a good opportunity for me to learn about research involving graduate students
in Japan because I do not have many other opportunities to learn about their research. The research themes
and results obtained by graduate students at other universities are also interesting. I got to know PhD students from other universities and talked about our research goals and concerns for the future. I also learned
about cutting-edge research on radioecology after the Fukushima accident from professors at the Universityof Tokyo. Several Japanese academic societies study radioecology, including forestry, agriculture, and ecology
societies, but there is no unified academic society for radioecology. Therefore, I would not have had a similar
opportunity in Japan.
I have presented my study at international conferences several times. On this occasion, I thought thatmy English was the best has ever been, although I still need to improve. As the audience were from various
backgrounds, my talk might have been too specific, difficult, and boring for many. Nevertheless, I believe thatmy research results are important and interesting, but I need to give a presentation that appeals more to a
non-professional audience.

2-3. SKB (Swedish Nuclear Fuel and Waste Management)

The process of disposal of radioactive wastes in Sweden is completely different from that in Japan. Sweden
seems to be 50~100 years ahead of Japan because Japan has not designated a disposal site for radioactive
wastes. I tried to identify differences between Japan and Sweden, but I could not. I assumed that the difference is due to differences in social and political systems; perhaps geological differences between Sweden andJapan also made site selection easier in Sweden, as Japan is frequently affected by earthquakes and volcanoes.
I was interested in the results of the site investigation at Forsmark from 2002 to 2007 because my researchbackground also includes cycles of materials such as carbon and nitrogen in forest ecosystems. I was impressed by the detailed environmental assessment conducted at Forsmark before building the repository. The
result of the environmental assessment is also important academically. As a PhD student studying material
cycles in a forest ecosystem, I wanted to join the site investigation team.
This was my first opportunity to see a boreal forest because my study sites are temperate forests in Japanand tropical forests in Malaysia. The coniferous forest in Forsmark was very beautiful, and the understory
vegetation and soil were very different from what I know in Japan and Malaysia.

3. Summary
My goals at the Japan-Sweden workshop were to learn about cutting-edge radioecology research in Japanand Sweden and emergency preparedness for radiation disasters in Sweden. I learned that radioecology is
evolving in both Sweden and Japan. This has increased my motivation. I also learned that Sweden is ahead ofJapan in terms of protecting humans, society, and the environment from radiation. The university in Sweden
has a course on radiation emergency preparedness, and careful environmental assessments are conducted in
Sweden before building nuclear facilities.

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5.5 Report on the Japan-Sweden Workshop
Tomoya Hori

Graduate School of Informatics, Kyoto University, 606-8501 Kyoto, Japan

1. Introduction
The Chernobyl nuclear plant accident was one of the first cases in which neighbouring countries faced radioactive contamination and its effects on human health. Japan has examined how countries such as Sweden
have coped with radionuclide problems. Sweden has experienced nuclear weapons fallout and is regarded asa pioneer of studies of radioecology, radionuclide contamination, and treatment management. Many articles
on Chernobyl and its effects on Sweden, including radioecology, have been published. Nevertheless, international conferences are one of the few opportunities for Japanese to discuss these issues with foreigners. This
workshop was a wonderful opportunity to collaborate and share our knowledge with Swedish pioneers onradioactive studies and to advance Japanese research.
I study fish movements in coastal areas in Fukushima affected by the 2011 earthquake and tsunami. There
are few reports on the fine-scale activities of fish and their ecology in disturbed environments, and suchinformation can contribute to environmental reconstruction activities following disasters. In terms of radioecology and food safety in Fukushima, radionuclide dispersal in marine food resources should be considered.
The fine-scale monitoring of fish movements may be a key factor for clarifying radionuclide uptake in fish.
At the workshop, I wanted to learn more about current and historical studies of radioecology in Japan and
Sweden, for future study ideas. The fisheries in Fukushima are still regulated and limited to small-scale trial
fishery operations. Many of the fishery people that I meet in the course of my studies want to return to thework they had before the earthquake. Radioactive contamination of fish and its effects on human health areimportant concerns. I hoped to get ideas on how to clarify these problems.

2. Workshop reviews
2-1 Workshop at the University of Gothenburg

I discovered a great deal of new information at the presentations in the workshop at the University of Gothenburg. First, I was surprised to learn that the Swedish regulatory limit for radioactive Cs in foods was 300
Bq/kg, albeit not for all food resources. The Japanese limit for food is 100 Bq/kg and some Japanese feel thatthe value is lax compared with the limits in other countries. I also learned that the radioactive contaminationof grasslands, which affects cows and milk, is important in Sweden, while Cs contamination of rice still attracts the most attention in Japan. These differences arise from cultural and historical differences between the
countries, and the food safety policies of each government have to consider the Cs contamination of food inways that protect food producers from consumption declines.
The most interesting information that I learned at the workshop was about pit (mining) lake studies. The
artificial aquatic environment in these lakes is contaminated with metallic elements from the mining effort.
This results in external dosing of visiting animals and people. The release of specimen fish is one possible
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way to test the radioactive uptake by fish in order to study the effects of radionuclides on animals in the lake.
My study can contribute to this research since the study of fish movement and distribution appears to beimportant experimentally.

2-2 Workshop at Stockholm University

I was more at home at the Stockholm University session because many speakers talked about the radionuclide contamination of animals. Although there were many interesting talks about the radioecology ofanimals (e.g. wild boars and amphibians) and plants (e.g. crops, rice, and wild radish), I found the study on
the intentions of customers to purchase salted salmon from Japan the most interesting. As I explained in
the Introduction and Subsection 2-1, consumers in Japan are still concerned about the safety of seafood andboth economic and social studies are essential to establishing safe marine products for recovering seafoodmarkets in Japan. Even if basic studies of the radioactive contamination of food resources clarify the various
safety issues, people may still not feel confident about food safety. This study showed that these concerns arealso important in other agricultural products and trade markets in other countries. Although the talk focusedon specific areas, I also learned how to use my fish ecology studies to clarify problems that fisheries in Fukushima are currently facing.

3. Summary
I had expected that this workshop would be a good opportunity to collaborate with Swedish scientists andto consider future avenues of research. I obtained a great deal of new knowledge and talked with pioneers inthe study of radioecology from Sweden and Japan. I developed some ideas for future studies and met Swedish
and Japanese scientists with whom I may have a chance to collaborate in the future.

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5.6 Long-term desorption kinetics of Csfrom contaminated soil
Kento Murota

School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8654, Japan

1. Introduction
It is necessary to investigate the mobility and kinetics of caesium (Cs) in the subsurface environment as
part of soil decontamination following nuclear accidents, as well as to assess the environmental impact ofthe disposal of high-level radioactive waste. Among the radionuclides contained in contaminated soils following the accidents at the Fukushima Dai-ichi and Chernobyl nuclear power plants, 137Cs is of particularconcern because of its long-term environmental effects due to its long half-life of 30 years. Radiocaesium isalso contained in spent fuel from nuclear plants. Furthermore, the mobility of 135Cs (which has a half-life of
approximately 2.3 million years) should be taken into account in the disposal of high-level radioactive waste.
In Japan, the locations for new repository sites for decontaminated radioactive waste and high-level radioactive waste have not yet been decided. This is due both to technical problems, such as understanding the chemical
properties of radiocaesium in soils, as well as to social issues. The Swedish nuclear fuel and waste managementcompany SKB has selected repository sites for spent fuels, even though Sweden suffered radioactive contamination due to the Chernobyl accident. In this workshop, we are interested in the differences between Japan and
Sweden in terms of public perception of the disposal of high-level radioactive waste and selection of repository sites. I am grateful to have had the opportunity to learn about these differences by visiting Forsmark andattending a research presentation by Dr. Kautsky, and from my many conversations with Swedish researchers.

2. Differences between Japan and Sweden
2-1 Public awarenessI was interested in the effects of the Chernobyl accident on public awareness of radiation and disposal ofradioactive waste. One Swedish researcher has stated that Swedish students are indifferent to the accident.
Although it is possible that there are different trends in other generations, the adverse effects of the accident
do not appear to be a significant concern, at least for now. This is thought to be because approximately 30
years have passed since the accident, which occurred in a country that does not share a border with Sweden.
The public confidence in atomic energy companies and the government in Sweden is particularly interesting. The main reason for lack of progress in feasibility studies in Japan is the opposition of local residents.
Another Swedish researcher stated that this confidence stems from a lack of failure incidents. After hearing
this opinion, I realized the need for greater effort from Japanese atomic energy companies and authorities torecover public confidence following the Fukushima Dai-ichi nuclear accident, which resulted in considerable
disaffection towards nuclear power, electric companies and the government’s handling of the disaster.

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2-2. Publication

SKB have investigated not only the subsurface environment, but also the surrounding ecosystem of geological repositories for long periods of time. A booklet is available from SKB providing a summary of theirresearch, and is accessible to the public. There are many introductions to individual researchers, with pictures
illustrating their research work. These are thought to be effective in providing a positive view of the researchers and their work, which helps to build public confidence. Although similar material is available in Japan,
these publications are mainly composed of data on the safety of disposal.

2-3. Technical aspects

Earthquakes or fault activities are important factors in the selection and assessment of disposal sites inJapan, whereas Swedish researchers have studied long-term models considering glacial periods, where repositories are covered by snow year round. In practice, however, the planning of the disposal of nuclear waste issimilar between the two countries. It follows that social aspects are particularly important in nuclear waste
disposal, and may indeed be of greater importance than the technical details of waste management.

3. Summary
My experience of this workshop showed me that there are significant differences in public confidence inrelation to the disposal of radioactive waste between Japan and Sweden and, furthermore, that public confidence is of crucial importance in the future development of the nuclear industry; indeed, it is arguably ofgreater significance than technological progress. In conclusion, in Japan we must concentrate our efforts torecover public confidence in the nuclear industry.

A photograph of a conversation with Dr. Nordén.

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5.7 Importance of international communication
among researchers
Suzuki Takashi

Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

1. Introduction
When I was a student at Kitasato University, which is located within the area affected by the 2011 greateast Japan earthquake, I lived in the tsunami-affected area and experienced the loss of my house and one of
my friends. Furthermore, I learned about several problems in the reconstruction of fishery industry when I
talked with acquaintances who worked in fisheries. One of the biggest problems was the economic damage
to the affected area caused by people avoiding purchasing fish products because of concerns about radioactive
contamination. Thus, I wanted to contribute to solving this problem and started my research on consumer
attitudes towards seafood produced in affected area.
After the great east Japan earthquake and Fukushima Daiichi nuclear power plant accident in 2011, somemedia and researchers reported that some foods produced in the affected area exceeded the radio cesium
standard, leading consumers to avoid purchasing them. This problem is similar to the situation in Sweden
after the Chernobyl nuclear power plant accident in 1986. In the case of Chernobyl, radioactive substances
leaked into atmosphere, and some of them reached Sweden. As a result, Swedish consumers and food producers worried about the radioactive contamination of food. Moreover, because Swedish researchers had
been monitoring radioactive substances in the field and hydrosphere, they had abundant knowledge about
nuclear hazards and the potential for damage to nature and society.
My purpose in participating in this workshop is to communicate with researchers from other countries not
only by presenting and discussing my research but also by integrating interdisciplinary knowledge.

2. Outcomes of the workshop
2-1. Recognition of the importance of international discussion

I recognized the importance of international discussion and the sharing of research themes, methods, andresults with researchers from other communities. In particular, comments about my research and an explanation of the Swedish government’s countermeasures in response to the Chernobyl accident encouraged
my scientific study of nuclear disasters. For example, Dr. Leif Moberg mentioned the regulation of 134Cs
and 137Cs; the limit is 300 Bq/kg in normal food and 1500 Bq/kg in some foods (e.g. freshwater fish andmushrooms). As these regulations differ from Japanese food regulations (100 Bq/kg in normal food), it was
important to me, and this information gave me an opportunity to assess people’s awareness of the regulationof radioactive substances in Sweden. In addition, this information about the Swedish regulations gave me achance to think about the possibility of reducing Japanese consumers’ concerns about the radiation standard
by providing information about Swedish regulations.
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Furthermore, many participants offered opinions about my research during discussions, breaks, and field
trips.
My research topic was consumer awareness of seafood produced areas affected by the 2011 great east Japan
earthquake. In particular, my interest was in consumers who wanted to contribute to reconstruction by purchasing and in behavior and concerns related to the radioactive contamination of seafood. Thus, I conducted
a questionnaire survey in 2012 and found that consumers who wanted to contribute to the reconstruction
through their purchasing behaviors had lower levels of concern about radioactive contamination. I presented
this result at Stockholm University, but many participants from the University of Gothenburg also offered
opinions over meals and during field trips. In particular, one participant offered the following meaningfulcomments and encouraged me to continue my research: “This is a new aspect compared with former research
about risk communication” and “It sounds interesting when the difference in consumer altruistic behavior
and consciousness is clarified by country”.

Fig.1 International human network involving participants of this workshop

2-2. Knowledge from different fields

As I am interested in research on radiation undertaken in other fields, this workshop was a good opportunity for me to learn about new points of view. Dr. Juan Mantero presented an introduction to research
focused on mining-related radioactivity in a lake. I was impressed by the demands placed on the lake as a
tourist site, which it had become because of its good scenery and clear water. However, the lake includes minerals that emit radiation, rendering it important to monitor for 226Ra to clarify the risk of radiation exposure
when people swim in the lake. This case requires the development of strategies to both the monitor the situation and inform the society about the results. Thus, I recognized that research topics related to radioactivity(including nuclear disasters) are related to not only the natural sciences but also the social sciences. Thus, aninternational and interdisciplinary approach is needed to solve these problems.

Fig.2 Opportunities to gain interdisciplinary knowledge

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3. Summary
This workshop provided information about the countermeasures taken by the Swedish government inresponse to the effects of the Chernobyl accident and about the research that has been conducted in thisdomain. In addition, participants from Japan gave presentations about the mechanisms by which radioactive
substances move and are adsorbed into the soil and organisms, including by the species living in the hydrosphere after the Fukushima Daiichi nuclear power plant accident. I also gave a presentation on the results ofmy post-disaster consumer research.
The main theme of this workshop is nuclear disasters. Thus, participants gave presentations related to thistheme and discussed it relative to their specialties. This kind of international discussion is important for thecommunication of and reflection on our research. Furthermore, it is important that researchers who focus
on topics that have natural and social science aspects participate in interdisciplinary collaborations so thatthey can adopt a broad view that extends beyond individual specialties. This workshop taught me about theimportance of international discussions and motivated me to engage in international collaborative work withresearchers from different areas.
Finally, I am grateful to the professors, secretaries, and participants who organised this forum and provided
this opportunity to me.

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5.8 What I felt throughout the Japan-Sweden workshop
Shuto Shiomi

Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan

1. Introduction
When I watched the news regarding the Fukushima Daiichi nuclear power plant (FDNPP) accident, I
realised that I wanted to perform research on the damaged area. Then I became a member of a laboratory ofRadioplant Physiology and have been performing research related to Cs transportation within rice plants.
The reason I chose this theme is that vast areas of paddy fields were damaged by radiocesium and there areareas where rice cropping is still suspended in the Fukushima Prefecture.
Before I visited Sweden, I had an understanding regarding the relationship between Sweden and theChernobyl accident. First, Sweden was the first country that alerted the world about the Chernobyl accident.
Second, after the Chernobyl accident occurred, Sweden focused on exploring the effects to the environmentand conducting counter measures for radionuclide contamination.
Based on my understanding, I thought that this Japan-Sweden workshop would allow me to obtain new
knowledge regarding radioecology and provide guidance for my research. Thus, I decided to participate inthis workshop.

2. People’s accurate understanding of radiation and the nuclear accident
2-1. After accident

In Sweden, the information pamphlet “Efter Tjernobyl (in English: After Chernobyl)” were distributed
to all households in the autumn of 1986 (Fig. 1). This pamphlet helped people understand the effects ofradiation and the Chernobyl accident. Since I observed numerous people who were confused by a variety of
inaccurate information regarding the FDNPP accident, I was impressed when I heard this topic and readthis pamphlet at Stockholm University. I appreciated the importance of disseminating correct information
to the people.

2-2. Final depository

I attended a presentation on the “final depository for spent nuclear fuel in Forsmark” by a member of the
SKB staff and understood that there are two necessary conditions to build the final depository; namely, safe
technical solutions and a consensus with the people who live in the district. In this presentation, the staff
member said, “Knowledge is power, but most power is people who live here”. These words left a strong impression on me. Surprisingly, nearly 90% of residents were in favour of having the storage site in their community in Forsmark. I believe that this consequence was due to the SKB’s long-running effort and people’s
earnest attitude to understand the necessity of the final depository. If people have an ambiguous understanding regarding the final depository’s safety and necessity, they may not agree with this policy.

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3. Summary
Through this workshop, I did not acquire new knowledge regarding my research; however, I learned newthings, such as the final depository and Sweden’s concrete efforts to cope with the Chernobyl accident, that I
was not aware of before visiting Sweden. Using this experience, I would like to focus on radiation issues andcontinue my research more deeply.

Fig.1 Efter Tjernobyl

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5.9 What I learned in Japan–Sweden workshop, 2015
Nanami Oshima

Faculty of Integrated Human Studies, Kyoto University, Yoshidanihonmatsu-cho, Sakyo-ku, Kyoto, 606-8501, Japan

1. Introduction
The Great East-Japan earthquake happened when I was a high school student in Kyoto. The disaster
caused by the tremendously powerful tsunami and the Fukushima Daiichi Nuclear Power Plant accident
made me think about what I could do for people in the Tohoku region, but I had no answer at that time.
However, when I had the opportunity to give a presentation about nuclear power plants last year, I learned
what researchers have done to deal with the nuclear power plant accident. That has motivated me to study
phytoremediation, which is one solution to the agricultural problems caused by the accident. I actually started
my study this April, but had few opportunities to communicate with others about the accident and associatedresearch activities. Therefore, I felt that joining this workshop would enhance my communication with others
and improve my research.
In addition, I was interested in how researchers in Sweden and other countries have dealt with the Chernobyl accident. People in the Tohoku region are still confused about radiation contamination and it is unclear
how long this situation will last. Furthermore, despite the Chernobyl accident, nuclear power plants in Sweden still generate most of the energy needed in Sweden. I believe that exchanging information with Swedish
researchers will provide clues about how to deal with the Fukushima accident.
This was also the first time that I presented my study. I have learned how difficult it is for me to convey
my thoughts well enough for others to understand them. In preparing for my presentation, I received a great
deal of advice from the academic staff and other participants. I found the process a bit difficult but verystimulating at the same time. These interactions helped me recognise problems in my study and motivatedme to study more.

2. What I learned in the workshop
2-1 The importance of having various views

I learned a great deal from both the Japanese and Swedish participants in this workshop. While my research has focused primarily on plants, other participants study diverse topics such as the effects of radiation
on humans, animals, and fisheries, and the spatial distribution of radioactive material. While listening to thepresentations, I came to feel that it was necessary to think of connections or relationships among the various
topics and fields of research. Professors in my faculty, the Faculty of Integrated Human Studies, often say that
it is necessary to integrate other fields in order to deal with problems, but I had not fully understood what
they meant. However, the presentations at this workshop, given from various perspectives, have given me
insight into this concept. In addition to collaborating with other researchers, I found that it is also importantfor me to approach my problem from various directions. Understanding this will clarify the steps to be taken
in order to tackle my specific problem.

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I also found that I need to understand the problem from the perspectives of both the arts and science. For
example, people might not be certain about the border between safe and dangerous levels of contamination in
food. As some presenters said, we cannot precisely identify a limit for what is dangerous. However, it is natural for people living in the contaminated area and those with children to worry about this kind of problem. I
feel that scientists should not only give these people scientific solutions, but also understand their viewpoints,
even if what they think is not scientific. This is the first step to knowing why people think the way that they
do and it is crucial in order to understand and evaluate problems scientifically.

2-2 The importance of knowledge

Visiting Forsmark during the workshop left a lasting impression. I had not considered spent nuclear fuel.
Visiting the repository has stimulated me to study how Japan deals with spent nuclear fuel.
I was also impressed how the importance of knowledge was stressed in the explanation of Forsmark. In
Japan, the TV, radio, and internet provide a great deal of information about nuclear power plant accidents andradiation. However, too much information can be confusing and makes it difficult to judge which information is correct. Some commentators say that nuclear power plants should be banned and viewers are affectedby the commentators’ opinions because they do not have enough knowledge of their own to counter them.
A lack of knowledge frightens people more than it should. I think this is one of the factors that confused
people after the nuclear accident in Japan. Electric power companies should provide this information directly,
including the negative aspects.
In addition, I was very surprised to learn that 80% of the residents agreed with the construction of the repository in Sweden. This was because SKB earned their trust through conversations and communication withresidents over a long period. I wondered whether this would be possible in Japan in the case of the construction of nuclear power plants. In Japan, the representatives change frequently and politicians seem to avoid
direct communication with residents, especially with regard to nuclear power plants. Even if the governor ofa city knows that some residents disagree with the construction of nuclear power plants, he might accept theplan because the city can get more money as a benefit of having a nuclear power plant. Consequently, politicians lose the trust of the people. I hope that this will change and that electric power companies will provide
enough information and give people the opportunity to ask questions.

2-3 About radiation

When we visited the University of Gothenburg, we had a chance to see some machinery and learn about
radiation. Although I had read about radiation in books, this was the first time I heard an explanation. It was
sometimes difficult to understand, but others helped me. I need to learn more about radiation and how it isapplied in various fields.
When I returned to Japan, I discovered that one of the groups at my university has developed a car for
emergencies similar to one I saw in Sweden. Although I did not known how my university was prepared torespond to accidents, my experience in Sweden helped me recognise these activities.

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2-4 What I learned from other participants

I learned not only about radiation and radioecology but also how I should deal with problems in my own
study. I was very nervous about giving my presentation and lost confidence in the results of my study because
there is a lot of room for improvement. However, one of the Swedish participants gave me some very good
advice: everybody was once a beginner! If I need to improve, I can get advice from others to help me toimprove. This advice cheered me. I had an opportunity to reflect on my study through my preparations andlistening to other presentations. I have also learned how to approach a study using appropriate experiments
and methods.

3. Summary
In this workshop, I learned the importance of having various views of a problem and thinking about therelationships among various factors. In addition, visiting the repository stimulated me to learn more about
nuclear power plants and radiation. I simultaneously discovered that I lacked knowledge on these issues. I
want to learn more about nuclear power plants and be able to evaluate the future of nuclear power. Other
participants also taught me how to approach my study, which will improve it.
Finally, I was able to spend some very stimulating days in Sweden. I appreciate all of the people involvedin this workshop and am grateful for having this precious opportunity.

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Chapter 6
Photographs of Activities

Gula stråket 2B at Sahlgrenska University Hospital

The emblem of “cruiser Sheffield” on the oldiron shield of the whole body counter at Sahlgrenska University Hospital

The campus map of Sahlgrenska University Hospital,
Gothenburg, Sweden. Dept of Radiation Physics, Institute of Clinical Sciences, located at Gula stråket 2B
A whole body counter

An old germanium semiconductor detector

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A pretreatment room for samples in the fieldMobile equipment for field sampling and measurementof radiation

A soil core sampler

A mini lecture for alfa ray spectrometry by Dr. R. Thomas

Simulated setting up of an electrodeposition
cell for uranium alpha source preparation

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Änggårdsbergen Nature Reserve

Gothenburg botanical garden andÄnggårdsbergen Nature Reserve
Gothenburg botanical garden
Japanese cherry tree, Prunus sargéntii
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Japanese cypress, Chamaecyparis obtuse in the nature reserve

Japanese pond in the nature reserve

The workshop participants at the hilltop of Änggårdsbergen Nature Reserve

The city of Gothenburg

The welcome event (mingel) at Dept of Radiation Physics

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Presentation by Prof. S. Mattsson

Presentation by Ms. N. Mitsuoka

Presentation by Ms. K. Ichikawa

394 | Sweden-Japan Workshop of Radioecology for Students, 2015

Presentation by Dr. R. Finck

Presentation by Associate Prof. N. Nihei

Presentation by Dr. G. Bengtsson

Chapter 6

Photographs from Activities | 395

Presentation by Mr. O. Hashimoto

Presentation by Ms. M. Takada

Prof. E. Forssell-Aronsson and Project Associate Prof. S. Miura

Presentation by Associate Prof. C. Rääf

396 | Sweden-Japan Radioecology Workshop for Students, 2015

A group photo of participants of
the workshop in Gothenburg

Japanese students at Gothenburg Central Station

Gothenburg
Central Station
Arrival at
Stockholm
Central Station

Chapter 6

Photographs of Activities | 397

Aula Magna, the venue of the workshop at Stockholm University

The meeting room of the workshop

398 | Sweden-Japan Radioecology Workshop for Students, 2015

Presentation by Mr. R. Weimer

Presentation by Associate Prof. N. Tanoi

Presentation by Mr. T. Hori

Presentation by Mr. T. Suzuki

Presentation by Mr. K. Murota

Presentation by Dr. S. Bengtsson

Chapter 6

Photographs of Activities | 399

Presentation by Mr. S. Shiomi

Presentation by Assistant Prof. N. I. Kobayashi

Presentation by Ms. N. Oshima

Presentation by Dr. U. Kautsky

The campus of Stockholm University

Workshop forfor
Students,
2015
Workshop of Radioecology
Students,
2015
400 | Sweden-Japan Radioecology

Prof. A. Wojcik was introducing the low dose
rate (mGy/h) gamma incubator (Cs-137 source).

The mixed beam (alpha / X-ray) exposure facility
PhD theses accepted in the laboratory
S

elcomeming w
m
ö
r
t
s
ur

party

Chapter
Chapter
6 6Photographs
Photographs
fromof Activities | 401

A coach ready to go to excursion for the final repository at
Forsmark
The map of Forsmark foundry
managed by VATTENFALL,
an electric energy company

Explanation of history of Forsmark
village’s former steel industry

Nine Japanese students
at Forsmark village

An old spruce-dominated forest within terrestrial monitoring sites in Forsmark,which is located above the underground final repository for radioactive waste of SKB

The old spruce-dominated forest

Understory of the old spruce-dominated forest

The workshop participants inthe old spruce-dominated forest
A monitoring site of frogs
and orchids in Labbo forest wetland in Forsmark

A pond in Labbo forest wetland

Chapter 6

Photographs of Activities | 403

Watching frogs or tadpoles?

Lingonberry, vaccinium vitisidaea in Labbo forest wetland

Picking mushroom
or lingonberry?

404 | Sweden-Japan Radioecology Workshop for Students, 2015

An edible mushroom (funnel chanterelle; Cantharellus tubaeformis) in Labbo forest wetland

Another mushroom, edible or not?

Tea break near lake Bolundsfjärden

Possible future wetlands study site in relation to hydrology andtransport mechanisms of surface hydrology at lake Bolundsfjärden

A d r a go

nfly

Comm

on toad
,

Bufo
Bufo.

Arable land in Forsmark

Chapter 6

Photographs of Activities | 405

Postscript

The present project, “Sweden-Japan Workshop of Radioecology for Students, 2015”, was co-organisedby the Graduate School of Agricultural and Life Sciences, University of Tokyo (GSALS UTokyo) and the
NPO Radiation Safety Forum. This project was also supported by the Watanabe Memorial Foundation for
the Advancement of New Technology and GSALS UTokyo.
There are two main aims of this project. One is related to education, allowing students to become familiar
with English presentations. In this context, the final report is also published in English, and all of the presentations given in Sweden were in English. English fluency is becoming increasingly important for everyone,
not only researchers. Given this, Master’s and Diploma students, in addition to PhD students, attended the
project.
The other aim is to develop a closer relationship between Sweden and Japan, focusing on radioecology,
which has been a maturing topic in Sweden since the Chernobyl accident, and has been drawing increasing
attention in Japan since the Fukushima Daiichi nuclear power plant accident in 2011. I was impressed by theattitude of the Swedish researchers in investigating and developing countermeasures to the contaminationof fields and forests. I am also confident that the Japanese team were able to provide fundamental data about
the agricultural situation in Fukushima to the Swedish researchers. I deeply appreciate the contribution of
the Swedish participants. It is important to maintain contact and arrange the next workshop soon.
Through the two workshops in Sweden, I was really impressed by the students’ research related to Fukushima. In addition, all of the students were able to benefit from the activities, namely, presentations anddiscussions in English. In fact, I found that the students tended to focus too much on the English language,especially English pronunciation and fluency. I strongly recommend that the students look back on theirpresentations and subsequent discussions and check the following points:•
Did they really get the audience to understand what they were talking about? Did they give up on
telling the story when they lost their way?
•
Was their attitude towards the audience sincere and earnest? When they made a mistake, did theylaugh the matter off ? Alternatively, did they try to cover it up by speaking fast?
•
Had they thoroughly prepared their presentation in advance?
The students who attended the project will have (or had already) noticed what is really important when
they speak in front of an audience. Improving English skills is not the only solution to giving better presentations in English.
Lastly, I would like to thank the leader, Dr. Miura, for coordinating all of the activities in the present
project. All of the participants were able to obtain valuable experience thanks to his consideration and care.

Keitaro Tanoi
The University of Tokyo
NPO Radiation Safety Forum406 | Sweden-Japan Radioecology Workshop for Students, 2015

Appendix 1

Statens strålskyddsinstitut
informerar om det radioaktiva nedfalletfrån kärnkraftsolyckan i Tjernobyl(“Swedish Radiation Protection Authority News of the radioactive fallout
from the Chernobyl nuclear accident”, a brochure introduced in p.245.)

Reprinted with the permission by Swedish Radiation Safety Authority

408 | Sweden-Japan Radioecology Workshop for Students, 2015

Appendix 1 Statens strålskyddsinstitut informerar om det radioaktiva nedfallet från kärnkraftsolyckan i Tjernobyl | 409

410 | Sweden-Japan Radioecology Workshop for Students, 2015

Appendix 1 Statens strålskyddsinstitut informerar om det radioaktiva nedfallet från kärnkraftsolyckan i Tjernobyl | 411

Appendix 2

Efter Tjernobyl?
(“After Chernobyl?”,a brochure introduced in p.246.)

Reprinted with the permission by Swedish Radiation Safety Authority413

414 | Sweden-Japan Radioecology Workshop for Students, 2015

Appendix 2 Efter Tjernobyl? | 415

416 | Sweden-Japan Radioecology Workshop for Students, 2015

Appendix 2 Efter Tjernobyl? | 417

418 | Sweden-Japan Radioecology Workshop for Students, 2015

Appendix 2 Efter Tjernobyl? | 419

420 | Sweden-Japan Radioecology Workshop for Students, 2015

Appendix 2 Efter Tjernobyl? | 421

422 | Sweden-Japan Radioecology Workshop for Students, 2015

Appendix 2 Efter Tjernobyl? | 423

424 | Sweden-Japan Radioecology Workshop for Students, 2015