Overview of the IER
Message from Director
Since its establishment in July 2013, Institute of Environmental
Radioactivity (IER) has tackled challenges associated with environmental radioactivity after the Fukushima Daiichi Nuclear Plant
accident. Meanwhile, our organizational framework has also beendeveloped into the current form by 2017, including the construction of both analytical and main buildings. In 2019, the IER has
launched the Joint Usage / Research Center program with otherﬁve institutes: Center for Research in Isotopes and Environmental
Dynamics (CRiED) of Tsukuba University, Institute of Radiation
Emergency Medicine (IREM) of Hirosaki University, Sector of
Fukushima Research and Development of Japan Atomic Energy
Agency (JAEA), Department of Radioecology and Fukushima
Project of National Institutes for Quantum and Radiological Science and Technology (QST), and National Institute for Environmental Studies (NIES) Fukushima Branch. Through this program,mechanisms have been established (strengthened) for eﬀectivelyfunctioning as a hub for accessing to Fukushima samples for collaborative researches between domestic / overseas researchers
and the IER researchers. Also in 2019, Masterʼs program of Environmental Radioactivity Science Major was established as partof the educational function of the IER, and the ﬁrst year students
enrolled. Following this, preparations for establishing a doctoral
program are underway toward the start in April 2021.
Researchers specializing in radioactivity and radiation in theenvironment are brought together at the IER. With radioactivity
and radiation as common subjects, the research ﬁelds behindeach researcher range from Topography, to Hydrosphere Ecology,
Forest Ecology, and Oceanography. The IER is interdisciplinary in
its nature, which naturally encourages internal collaboration andmay allow researchers to initiate new research, with ﬁnding new
perspectives in the gaps between the research ﬁelds that are overlooked in the conventional research targets.
Furthermore, researchers in countries that own nuclear power
plants and in neighboring countries pay close attention to the impacts of nuclear accidents on the environment and wildlife fromthe perspective of preparing for the next radioactive contamina-

What Our Logo Representstion. Accordingly, the researchers who study environmental radioactivity in Fukushima become naturally international. Since its
establishment, the IER has continued international collaborative
researches based on the scientiﬁc interests common to researchersin each country. We will continue to promote and enhance collaborative research.
In Fukushima, which was aﬀected by the nuclear accident, thefocus gradually shifted to the long-term issues from the urgent
challenges that contribute to the emergency measures at the timeof the IER establishment. In response to this, we need to switch
our research subjects to focus on long-term issues. One of the policies for long-term researches is to explore the basics with radionuclide and radiation in the environment put into perspective. For
example, in the ﬁeld of Environmental Dynamics, it is essential toelucidate the basics of hydrological and ecological mass transfer,and as for the radiation-induced morphological abnormality, it isessential to study the basics of morphogenesis mechanisms. It is
expected that these approaches will beneﬁt in suggesting measures
based on a deep understanding about the environment and nature.
In addition to its interdisciplinary and international characteristics, most importantly, the IER established at Fukushima University after the nuclear accident, has deep ties with the local community. We believe that it is important to value communication withthe local people, to conduct research that ﬁts to the changes of
their situation and interests, and to continue to share our research
results and ﬁndings to the local community. We will continue to
strive to manage the institute for eﬀectively conducting researchwith cooperation of the people concerned and local communities.
We would be grateful for your continued support and cooperation.

Our logo symbolizes environments such as water, land, and air. It expresses the dynamics of radioactive
materials in the environment, and the dynamics of ecosystems. Its round shape expresses an attitude to be
in harmony with the natural world. The colors of blue, green, and orange used in our logo represent thewater/sea, earth/forests, and air/sunset, respectively. The sphere in the upper right corner represents a clean
earth that is realized by the integration of studies and also stands for research outcomes and added values.
The slanting cut in the letter “I” expresses our wishes for ever-increasing progress and outcome.

2Research Projects
P20 Speciation Radiochemistry
Cs
Cs

P12 Ecosystems

Cs

Cs

Cs

Cs
Cs

Cs

Cs

Cs

Cs Cs
Cs
Cs Cs Cs

Cs

Cs

Cs
Cs

Cs

Cs

Cs

P4

P8

Comparison

Cs
Cs

Cs
Cs
Cs

Rivers and Lakes

Oceans

P16 Measurement andAnalysis

P24 Modeling

Collaboration Agreements▪International▪International Atomic Energy Agency (IAEA)▪Colorado State University (CSU, USA)
▪University of Georgia (UGA, USA)
▪University of Portsmouth (UoP, UK)▪Scottish Universities Environmental Research Centre (SUERC, UK)▪Odessa State Environmental University (OSENU, Ukraine)▪Chernihiv National University of Technology (ChNUT, Ukraine)▪Ukrainian State Specialised Enterprise “Ecocentre”▪Institute of Mathematical Machines and Systems Problems of the Ukraine
National Academy of Science (IMMSP NASU)▪National Academy of Sciences of Ukraine Institute for Nuclear Research (KINR NASU)▪National University of Life and Environmental Sciences of Ukraine (NUBIP)▪Chornobyl Research and Development Institute (CRDI, Ukraine)▪Norwegian University of Life Sciences (NMBU)▪National Food Chain Safety Office (NFCSO, Hungary)▪Department of Chemistry, Faculty of Science, University of Chittagong (CU, Bangladesh)▪Commissariat à I'Energie Atomique et aux Energies Alternatives (CEA, France)▪Agence Nationale pour la Gestion des Déchets Radioactifs (ANDRA, France)▪Institut de Radioprotection et de Sûreté Nucléaire (IRSN, France)▪Institute of Radiobiology of National Academy of Science of Belarus (IRB)▪Belgian Nuclear Research Centre (SCK-CEN)▪Faculty of Geography, Moscow State University (MSU)▪Federal State Budgetary Institution “Russian Institute of Radiology and Agroecology”ofMinistry of Science and Higher Education of the Russian Federation (RIRAE)▪Nuclear Safety Institute of the Russian Academy of Sciences (IBRAE RAN)
▪Japan▪Institute of Environmental Sciences (IES)▪National Institute for Environmental Studies (NIES)▪Japan Atomic Energy Agency (JAEA)▪Quantum Medical Science Directorate of National Institutes for Quantum andRadiological Science and Technology (QST)▪College of Science and Engineering, Kanazawa University▪Hiroshima University▪Institute of Radation Emergency Medicine (IREM), Hirosaki University▪University of Tsukuba ▪Nagasaki University▪Tokyo University of Marine Science and Technology▪Fukushima Medical University

Overview of the IER

3

Project 1

R ivers and Lakes

01

44

02

03

05

06

04

07

08

［01］Setting up an artiﬁcial grass mat on Niida River ﬂoodplain ［02］Water sampling from an irrigation pond ［03］Dose rate survey of the waterfrontpark ［04］Study of the Niida River ﬂoodplain ［05］Runoﬀ plot ［06］Surface runoﬀ and soil erosion during heavy rain ［07］Decontamination siteeroded by rainfall ［08］Sampling of suspended sediments in the river

Project 1

Rivers and Lakes

5Project 1

R ivers and Lakes
Fate and Transport of Radionuclides in Soil-Water
Environment; Understanding Their Dynamics for
Future Prediction

Why Did We Start the Project?

Radioactive materials released as a result of a nuclear
accident are dispersed in the environment. Following the
Fukushima Daiichi nuclear accident, the released radionuclides were deposited on the ground and entered water
bodies. Deposited radionuclides were then subjected totransport by surface runoﬀ and wind resuspension. Understanding transport processes of radionuclides is required forpredicting their redistribution in the environment, whichis critical for reducing radiation risks. Of the accidentally
released radionuclides, 137Cs is of higher environmental
signiﬁcance because of its long half-life and large amounts
released. 137Cs can be easily associated with sediments because of its strong aﬃnity to soil particles and, during rainfall, it is transported with surface runoﬀ to the ocean via

river systems. Radionuclides partially accumulate in closed
water systems such as lakes and ponds and are slowly remobilized to water due to ion exchange. These phenomena
were elucidated through the studies of the environmental
behavior of radionuclides occurring as a result of global
fallout after nuclear bomb testing and contamination following the Chernobyl accident. The geographic setting ofFukushima Prefecture, however, is characterized by higher
precipitation and steeper topography as compared to otherareas studied and, therefore, the site-speciﬁc behavior ofradionuclides needs to be understood. From this respect,
the Rivers and Lakes group is tasked to explore how theclimatic and geographical conditions of Fukushima Prefecture inﬂuence the current and future radiation situation.

To better understand particulate 137Cs migration throughthe river system and related temporal changes in the contamination levels, the Rivers and Lakes group has conducted monitoring on the Niida River located in the areas
contaminated after the Fukushima accident. The characteristics measured on the river basin include the river waterﬂow rate, suspended sediments discharge and 137Cs activity
concentration in suspended sediments, which are used toestimate 137Cs wash-oﬀ from the catchment. Accumulationand losses of sediments and 137Cs on the ﬂoodplain during
the ﬂoods are also being determined. In addition, we studied the 137Cs activity concentrations in sludge at the sewage-treatment plant of the Abukuma River system. For further understanding temporal variations in the 137Cs activity
concentration in closed and semi-closed water systems,
samples of water, sediments and soils are collected on aregular basis on the catchments of four irrigation ponds inOkuma town.
The catchments contaminated after the Fukushima accident have become a source of long-term secondary radio-

active contamination of rivers and lakes due to radionuclide
wash-oﬀ by surface runoﬀ. For deepening our knowledgeof radionuclides wash-oﬀ from areas of various land use,such as forest, farmland and grassland, observational facilities (runoﬀ plots) were set up in Date City. Using theserunoﬀ plots, samples of runoﬀ water and eroded sediments
are collected to quantify 137Cs discharge in particulate anddissolved states.
Accumulation of radionuclides due to sedimentation andtheir loss due to erosion lead to changes in the air dose rate(indicative of external radiation risk). For example, in thecases of radionuclides removal from soil surface by erosion
or their burial below fresh uncontaminated sediments, theambient air dose rate is supposed to decrease. For keeping
track of such changes; i.e., identifying places and time
when such changes occur, we continuously measure the air
dose rate at our observation/monitoring sites.
Another important task is evaluating eﬀects of decontamination. In order to investigate the impact of decontamination on migration of radionuclides on contaminated

How Do We Study?

6catchments, we have set up runoﬀ plots on a decontaminated area in Kawamata Town. Additionally, geomorphological surveys were conducted in the Iitate Village using
a 3D laser proﬁler for better understanding of soil erosion
processes on decontaminated lands.
The comparative analysis of data on radionuclide behavior in the environment has shown that Fukushima-derived
137
Cs features a stronger binding to particles than was
the case at Mayak and in Chernobyl, which is conducive
to faster scavenging of 137Cs in surface waters and predominant transport of 137Cs on suspended material withsurface runoﬀ and river ﬂow. Fukushimaʼs soils contain ahigher amount of clay, which contains a mineral that caneasily adsorb and retain 137Cs. Our analysis of data on theradionuclides activity concentrations in sludge at the sewage-treatment plant has shown that three years after theaccident, the concentration of 137Cs in sludge decreased andwas about one-tenth of the concentration measured immediately after the nuclear disaster. Fukushimaʼs sewage treatment system is diﬀerent from systems in Europe including
Chernobyl and, consequently, the 137Cs concentrations insludge in Fukushima are relatively low.

Our study of 137Cs in the ponds of Okuma Townshows that the ratio of particulate 137Cs and dissolved
137
Cs is approximately 7:3. Similar to what was found in
Fukushima rivers, 137Cs was found to be strongly boundto sediments, and the total activity concentration in water column was found to be higher with increasing suspended sediments load in water. We will continue monitoring 137Cs activity concentration in water to elucidate
the radionuclide seasonal variations and their controlling
factors.
The undertaken measurements of air dose rate indicate that sediment transport during typhoon extreme
ﬂood events lead to a decrease in the air dose rate on
the river ﬂoodplains. A sharp decrease in the air dose
rate after a heavy ﬂood was observed on the ﬂoodplainof Niida River system, which can be explained by lesscontaminated coarse-grained sediments covering morecontaminated sediments below.
Investigations of the decontaminated areas are providing an insight into the inﬂuence of decontamination.
Our studies using the runoﬀ plots indicate that the 137Cs
activity concentration in sediments on decontaminatedareas has decreased almost by half, as compared to those
before decontamination. Observations of the Niida Riverbasin are indicative of a decreasing trend in 137Cs activity
concentration of suspended sediment in the river, thecatchment of which is being decontaminated. These results suggest that decontamination causes 137Cs activity
concentration to decrease in sediments transported fromland to rivers and lakes. Our current task is to better understand how decontamination inﬂuences dynamics of137
Cs and sediments on the river basin scale.

What Did We Find?

How Will the Research Benefit Society?

Knowing the current situation and better understanding how radionuclides will behave in the future in rivers and lakes is essential from the standpoint of reconstruction of safe living and industrial
activities. It should also be remembered that waterfrom rivers and reservoirs is used for agricultural
purposes. Determination of activity concentrations
and speciation of radionuclides, as well as theirtemporal dynamics in the soil-water environment,is critical for safe and appropriate farming. It is alsoof vital importance to understand 137Cs uptake byaquatic organisms, including ﬁsh, particularly for recovery of the ﬁshing industry. Quantitative analysesof accumulation of radionuclides in waterfront parks
provide an estimate of radiological risk in the area.
The data obtained by our group are crucial for pre-diction of radionuclide migration in the environment.
Numerical model simulations are used to predict future large-scale spatial and temporal distributions ofradionuclides. Validation and calibration based on observational results can help to improve the accuracyof model simulations. Our activity allows us to collectvaluable datasets and thereby contributes to better
prediction of radionuclides fate.

(PIC) The Niida River(PIC) A reservoir in Okuma Town

Project 1

Rivers and Lakes

7

Project 2

Oceans

01

88

02

03

04

05

07

06

08

［01］R/V Umitaka-maru, Tokyo University of Marine Science and Technology conducted a research cruise in the waters oﬀ the Fukushima Daiichi Nuclear Power
Plant ［02］Retrieving a seawater sampler that collected seawater at desired depths between the surface to just above the sea bottom. ［03］Drawing collectedseawater into a container onboard ［04］Retrieving a net used for collecting biota samples ［05］Radioactivity screening survey on biota samples just after being
collected ［06］Sorting biota samples by species in the laboratory ［07］Sampled sediment ［08］Sampling surface seawater at Tomioka, Fukushima Prefecture

Project 2

Oceans9

Project 2

OceansUnderstanding the dynamics of radionuclides
in the marine environment is an importantclue for the evaluation of radiation dose eﬀects
on human society through food chain

Why Did We Start the Project?
How are radionuclides transported to the ocean

Artiﬁcial radionuclides released in the environment will bedeposited on land and ocean surfaces mainly due to precipitation(wet deposition), gravity, or its interactions with ocean surface(dry deposition). In addition, artiﬁcial radionuclides deposited onland can be transported to the marine environment via rivers, theatmosphere. Or, they are directly introduced into the marine environment from facilities located on the coast.

Behavior of radionuclides in the ocean

Artiﬁcial radionuclides spread throughout the ocean due toadvection and diﬀusion. Part of them are deposited in sediments
or transported into ecosystems as sinking particles. Such behaviorof radionuclides is called “biogeochemical cycles”. Although spatiotemporal distribution of radionuclides in the ocean is complicated by various factors, understanding biogeochemical cycles ofradionuclides results in evaluating radiation dose eﬀects on humansociety through food chain.

How Do We Study?

In our project, we conduct the following studies in collaboration withother institutions to clarify the biogeochemical cycles of artiﬁcial radionuclides in the ocean released by the accident at TEPCO Fukushima
Daiichi Nuclear Power Plant (FDNPP).

1.Field observation in estuarine and coastal waters,
and the ocean/Modelling & simulation/Laboratory
experiments with a method of solution chemistry
We collect and measure samples such as seawater and sedimentsfrom estuarine and coastal waters, and the ocean in order to understand the dynamics of radionuclides in these systems. We also estimate the amount of radionuclides (ﬂuxes) which ﬂow into the ocean
through rivers. In addition, we conduct laboratory experiments based

10

What to understand

It is important to study biogeochemical cycles in the oceanand how artiﬁcial radionuclides reach the ocean from rivers
and the atmosphere. It is also important to understand “howmuch of the radionuclides are deposited in the bottom sediments of the ocean and transported into ecosystems”. Thus,ﬁeld observation is required. Modelling & simulation andlaboratory experiments under the environmental conditions
are also necessary for further evaluation. In addition, there
are natural radionuclides and stable nuclides in the ocean as
natural analogue to artiﬁcial radionuclides. Understanding
their behaviors also helps to predict those of artiﬁcial radionuclides.

Food chain

Overview of biogeochemical cycles

on their particle-water interactions, in order to elucidate the factorsof desorption of radionuclides in particulate phase along the salinity
gradient from rivers to the ocean.

2.Transfer parameters of radionuclides from seawater to sediments or organisms

We obtain transfer parameters to understand how much of theartiﬁcial radionuclides are transported from seawater to sediments ororganisms. Using radioactive data on sediments, organisms, and corresponding seawater, we calculate the ratio of radioactivity between
the samples and seawater, as a transfer parameter. This information
is important for modelling & simulation to evaluate the eﬀects ofradionuclides to human society through food chain.

3.Prediction of long-term dynamics of artificial
radionuclides in the ocean using natural radionuclides and stable nuclides

What Did We Find?

From the investigations carried out so far, we havefound some spatiotemporal changes of artiﬁcial radionuclides discharged into the ocean by the FDNPP accident.

1.Dynamics of radiocaesium in seawater and sediments during the two years immediately after theaccident

Radiocaesium discharged into the ocean by the accident decreased
rapidly due to the mixing of the plume with relatively uncontaminated open-ocean waters. It was also found that vigorous vertical mixing during the winter contributed to the downward ﬂux of part of the
FDNPP-derived radiocaesium into bottom waters. Additionally, we
revealed that at least 0.2 % of the radiocaesium directly discharged
into the ocean was deposited in sediments.

2.Mass balance of radiocaesium in seawater around
FDNPP

We investigated the inventory of radiocaesium in the coastal water oﬀ Fukushima Prefecture and neighboring prefectures (surface
area: 6160 km2, volume: 753 km3) from May 2011 to February 2015.
The rediocesium inventory about four years after the accident wasapproximately twice the background inventory. Quantitative analysis
suggested that the on-going direct discharge from the FDNPP is theprincipal source of radiocaesium to maintain the relatively high inventory in the oﬀshore area.

By understanding the spatiotemporal distributions of radionuclides
and stable nuclides existing in the marine environment, we elucidate
the long-term behaviors of some artiﬁcial radionuclides of which
dynamics have not been fully understood yet.

3.Influx of FDNPP-derived radiocaesium into the
Sea of Japan

A nationwide investigation of radioactivity that has been conducted since 1984 in coastal areas where there are nuclear power plants
around showed that the FDNPP-derived radiocaesium was transported to the Sea of Japan by the Tsushima Warm Current throughthe Tsushima Strait. The net increase of radiocaesium inventory in
the Japan Sea through the addition of FDNPP-derived radiocaesium
accounts for less than 1% of the total ﬂux from the FDNPP to theocean.

4.Estimation of riverine radiocaesium fluxes to themarine environment

Part of radiocaesium deposited on land is eventually transported
to the ocean through rivers. In order to study the eﬀects of radiocaesium ﬂuxes from rivers to the ocean, we conducted laboratory experiments. As a result, desorption of this nuclide from riverine particles
by change of salinity from rivers should be considered for the total
radiocesium ﬂux in dissolved phase. However, since the extent ofdesorption depends on the physico-chemical properties of the particles, laboratory experiments are also highly required to evaluate therelationship between desorptive behavior and particle composition.

How Will the Research Benefit Society?
● Outreach activities for the explanationof principal information on biogeochemical cycles in order to support
public better understanding
Fisheries have been a basic industry in Japan. Ensuring the integrity of the marine environment, especially the safety of ﬁshery products and their impacts
on human society through the food chain, with respect
to radioactivity after the FDNPP accident is a high priority of the public.
We will continue to provide principal information of
the current status of the radio-contaminated marine
environment for the dose assessment by publishing
results to the scientiﬁc journals and by presenting to

the public. We believe that outreach activities help toprevent spreading of bad rumor based on the wrong
information.

● The research of radionuclides plays animportant role to solve other issues

Radionuclides and applying their radioactive decay
and isotope eﬀects can be used as analogues for tracing
the transient dynamics of materials. For example, naturalradionuclides are used to determine not only the sourcesof water masses but also biogeochemical dynamics ofother contaminants. They are also used to trace elements
in aquatic systems such as rivers, estuaries and oceans,
thereby providing us clues to solve climate change or evenother new environmental problems.

Project 2

Oceans11

Project 3

Ecosystems

01

12

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07

03

08

05

04

06

09

［01］Fukushimaʼs rich nature, forest and stream ［02］Sampling a tree using an increment borer ［03］Biopsy of contaminated boars ［04］Investigating the
distribution of radiation in Lake Numazawa to determine contaminant transfers to ﬁsh ［05, 06］Research on the behavior of wild boar and their radiationdose by using special GPS-dosimeter collars ［07］Laboratory preparation of samples to examine microbial community structure ［08］Studies of ﬁsh at acontaminated reservoir in Okuma Town ［09］Research on landlocked masu salmons at the Katsurao River

Project 3

Ecosystems

13

Project 3

Ecosystems
Research on the Behavior of Radioactive
Materials in Ecosystems and Radiation
Eﬀects on Plants and Animals

Why Did We Start the Project?

Our ecosystem group conducts research related to Radioecology.
[Radioecology] is a branch of science that studies the
behavior of environmental radioactive materials anddetermines the eﬀects of radiation on humans and theenvironment. It is an integrated science covering multiple
disciplines, such as nuclear physics, chemistry, biology,
toxicology, physiology, ecology, modeling, and risk analysis. Naturally occurring radioactive materials have existed
in our atmosphere, lands, water, plants and animals since
the earthʼs formation. All creatures are therefore routinely
exposed to background radioactivity. The cells of all creatures have evolved highly eﬀective mechanisms to repair
damage caused from such low-level radioactivity.
However, when accidents occur at nuclear facilities,

How Do We Study?

We conduct ﬁeld research on the radioactive contamination of plants and animals within aquatic and terrestrial
environments of the Fukushima Prefecture, as well as conduct research under more controlled laboratory conditions.
We also study the eﬀects of radiation on plants, animals,
and microbial communities. The six members of the Ecosystem group contribute their diverse backgrounds and expertise and jointly collaborate on various research projects.

Radioactive caesium concentrations when
dissolved in water, and when the Cs is
attached to small particles suspended in
the water column
The Abukuma River, Lake Hibara, and Lake Numazawa

Trends in radioactive caesium concentrations in fish and how they take up radioactive caesium
14large amounts of man-made radioactive materials canbe released into the environment. It is then necessary toknow the environmental behavior of the released radioactive materials to evaluate the risks to humans and theenvironment. The Fukushima Daiichi nuclear accident released large quantities of radioactive materials into the environment, including radioactive caesium. In view of this,
we investigate where the radioactive contamination has
been distributed among environmental components (air,soil, lakes, rivers, agricultural lands, forests, plants andanimals). We also measure the radiation dose received byplants and animals and determine their associated healthrisks. We then develop computer simulation models thatallow us to predict how the contaminantʼs concentration,
distribution, and health risks will change with time.

The Abukuma River system, rivers in Hamadori, andreservoirs around the Fukushima Daiichi Nuclear
Power Plant

Radioactive caesium in forest ecosystems

Yamakiya area in Kawamata Town and the area surrounding the Fukushima Daiichi Nuclear Power Plant

Tracking wildlife, measuring their contaminant levels and radiation dose
The evacuation zone and the area surrounding the
Fukushima Daiichi Nuclear Power Plant

Influence of radioactive caesium contamination on microbial composition of forest
soil
The area surrounding the Fukushima Daiichi Nuclear
Power Plant

What Did We Find?

Radioactive caesium concentrations when
dissolved in water, and when the Cs is attached to small particles suspended in thewater column

Our research showed that radioactive caesium concentrations in lakes and rivers, in both the dissolved
and suspended states, decreased rapidly after the nuclear accident.

Trends in the radioactive caesium concentrations in fish and how they take in radioactive Caesium

We found that radioactive caesium concentrations
in landlocked masu salmon in rivers of the Aizu area
and west of Nakadori contained low levels of radiation.
Whereas, there were still some samples with caesium
concentrations above the reference value (100 Bq/kg)
from tributaries northeast of Nakadori. This meansthat fresh water ﬁsh, including those living in mountainstreams, retain radioactive caesium for long periods
and are thus subject to the eﬀects of chronic exposures.
We also found that radioactive caesium concentrations
in ﬁsh from reservoirs around the Fukushima Daiichi
Nuclear Power Plant are among the most contaminatedand can have radioactivity concentrations that reachseveral thousand becquerels per kg.

Radioactive caesium in forest ecosystems

We found that radioactive caesium initially deposited in the top crowns of trees mostly transferred to thesoil, due to defoliation and rainfall in the forest ecosystem (as of 2016). New leaves increased in radioactive
caesium concentration. This suggests that their intakeof radioactive caesium was from the contaminated soil
via root uptake. We also found that a high percentage
of Japanese red pine trees exposed to radioactivity inthe juvenile stage have morphological abnormalities.

Tracking wildlife, measuring their contaminant levels and radiation dose

We found that boar and raccoons prefer the areas
evacuated by humans, even though these are areas
with the highest radiation levels. Boar and raccoons
are increasing in the evacuation zone because of theabundance of abandoned homes that provide shelter.
Fukushima boars, like those at Chernobyl, can containvery high radioactive caesium levels, several thousandsof becquerels per kg. Using specialized GPS collars that
contain dosimeters, we found that the dose from external exposure experienced by Fukushima boars can be
far greater than the dose they receive from ingesting
radioactive food and water. We also found that the levelof external dose can vary greatly over short time periods (less than a week) because of the large variation incontaminant levels that exists in environments.

How Will the Research Benefit Society?
Our research has documented the level of radioactive contamination in many diﬀerent environmental
components of Fukushimaʼs ecosystems. Information
on radioactive contaminant uptake by various ecosystem components is useful in understanding thetransport and fate of radiocaesium contamination
within the environment. For example, the data collected by the Ecosystem Group will make it possible
to estimate the radiation dose received by humans as
inﬂuenced by forest and forest products. This is important to people that return to their homes after theevacuation order is lifted. Our data provide additional
information on the distribution and habits of wildlifethat are considered pests because they are destroying property and could potentially spread disease.
Moreover, research on radiation eﬀects to wildlife
can provide insights into what humans might haveexperienced if evacuation orders were less stringent.
The IER openly shares the results of our research,and strives to be unbiased and neutral in presenting
our scientiﬁc data to general citizens, administrative
bodies, and domestic and foreign researchers. Suchscientiﬁc information is extremely important to thepeople of Fukushima, as well as those residing near
the 442 nuclear reactors the world-over (Source:
IAEAʼs PRIS as of March 28, 2016).

Radioactive materials moving in the ecosystem

Project 3

Ecosystems

15

Project 4

Measurement and Analysis

01

16

02

07

05

08

03

04

06

［01］Assembling an underwater robot by a lake ［02, 07］Adjusting an ICP-MS system for rapid analysis of radioactive strontium ［03］Outdoor radioactive
nuclide mapping using a portable gamma-ray spectrometer ［04］Minerals contained in soil (observation using an optical microscope and transmission electron
microscope) ［05］A full view of the underwater robot for sampling soil ［06］Test operation of the underwater robot in the lake ［08］Press release on aradioactive strontium rapid analysis technique

Project 4

Measurement and Analysis

17

Project 4

Measurement and Analysis
From Environmental Measurement to InfinitesimalScale Analysis Toward the Establishment of New
Measurement and Analysis Methods

Why Did We Start the Project?

“Analysis” refers to measuring, separating and looking.
Since the dawn of history, humans have been conducting
analysis in a broad sense to obtain information essential
to making judgements and eﬀectively proceeding with
the next action or step. That is to say, everyone conducts
analysis in order to make judgements or decisions. Analysis is not a basic act limited to only scientists, but is an
integral part of policymaking in administrative bodies.
Shorter, more accurate analysis allows swift decision-making for the next step. In other words, swiftness
and accuracy are very important keys in measurement
and analysis.
What is being sought in the ﬁeld of measurement
and analysis following the Fukushima Daiichi nuclear
accident is “the conducting of measurements in environ-

How Do We Study?

Our measurement and analysis project is developing
devices for measuring and analyzing radiation and radioactive nuclides (development of new measurement/
analysis devices ready for investigation/research of theenvironmental dynamics of radioactive nuclides in forests, rivers and lakes). Furthermore, we are developing
novel analysis techniques using conventional analyzing
devices for evaluating radioactive nuclides quantitatively
and swiftly, as well as for analyzing the environmental
dynamics of radioactive nuclides at the micro-level. Examples include development of:an underwater robot capable of sampling sediment on the lake bottom without destroying the layered structure of
sediment in deep lakes such as Lake Inawashiro.
a handy mapping system, combining a18

ments never before experienced by humans.” Although
this nuclear disaster is often compared to the Chernobyl
accident, Fukushima is similar to, but not the same as
Chernobyl due to the fact that Fukushima is hot andhumid, has a precipitous landform, and has a very fasthydrological circulation. There are many phenomenathat are being measured for the ﬁrst time in this environment; however, it is diﬃcult to conduct measurement
because the measurement environment is severe in somecases. Therefore, it is necessary to conduct analysis andmeasurement in parallel with the development of new
measurement techniques. While it is important to obtain
new information through such measurement and analysis, continued execution of these activities is essential inorder to maintain a safe environment.

portable gamma-ray spectrometer andGPS, capable of measuring the distribution of radioactive nuclides in forests andagricultural land swiftly and with a highdegree of accuracy.
a radioactive strontium ( 90Sr) rapid detection system integrating an automatedmulti-step 90Sr separation/concentration
technique and a high-accuracy separation detection technique using ICP mass
spectrometry (ICP-MS).
an analysis technique for imaging the
micro-level distribution of a radioactive
material in minerals or cells by an autoradiographic imaging technique and alocal structure analysis technique using
an electron microscope.

What Did We Find?

Development of an underwater robot capable of preserving layered structure of sediments during lakebed sampling

Shipments of several kinds of fresh water ﬁshsuch as the landlocked masu salmons and Japanese daces from lakes in the Fukushima Prefecture
are still suspended. One of the reasons for thissuspension is the possible contamination of lakes
with radioactive materials (134Cs and 137Cs) broughtby meltwater and rainfall coming from mountain
forests. However, since a detailed mapping of radioactive concentration in the lakes has not been conducted, the dynamics of radioactive materials are
unknown. In view of this, we are developing a small
and lightweight underwater robot that allows easy
operation to realize a technique for obtaining coresamples without destroying the layered structure ofbottom sediments. We hope to determine the stateof radioactive materials in the bottom sediment ofthese lakes.

Development of a radioactive nuclide mapping system using a portable gamma-ray
spectrometer

Environmental radioactivity monitoring using
conventional survey meters does not allow monitoring of the distribution of environmental radioactive
nuclides. We are developing a new system for mapping the distribution of radioactive materials in agricultural land and forests swiftly with a high degreeof accuracy by combining a handy, high accuracy
detector capable of measuring gamma-ray spectraand determining the quantity of radioactive nuclides
with GPS.

Radioactive strontium ( 90Sr) rapid analysis
technique

Unlike caesium, mass atmospheric diﬀusion ofSr, which is a nuclide emitting beta rays, is hardly
observed. However, 90Sr is still present in the nuclear
reactor building in high concentration. Conventional
measurement based on beta-ray measurement normally takes two weeks to one month since complicated chemical separation is necessary. We are focusing
on the mass separation capacity of ICP-MS (massseparation capacity and isobar removal function) andstarted development of a technique, not for measuringbeta rays but for separating and detecting radioactive
nuclides on the basis of their mass. By integrating an
automated multistep technique for separation (Sr isolation) and concentration with the functions of ICPMS, we have succeeded in establishing an analysis
technique that allows rapid and accurate (down to 1
Bq/L or lower) measurement.
90

Development of a technique for imaging
micro-level distribution of a radioactive
material

Research on the transfer process (e.g. from forests
to rivers or from soil to creatures) of environmental
radioactive caesium to a clay mineral, abundantly
contained in Fukushimaʼs soil, is gathering attention
as a “reservoir of radioactive caesium” since it has ahigh Cs adsorptive capacity. We are trying to ﬁnd “towhat site inside the clay mineral Cs is likely to adsorb” by an autoradiographic imaging technique anda local structure analysis technique using an electron
microscope.

How Will the Research Benefit Society?
The IER is advancing research so that ourmeasurement and analysis may clarify the situation of environmental radioactivity, which may
contribute to the realization of a safe and secureenvironment for local residents. Environmental
sampling, rapid analysis of radioactive nuclides
and inﬁnitesimal-scale analysis are some of thetechniques that have been developed by our measurement and analysis project, which, together
with other international research projects of the
IER, contribute to the elucidation of environmental dynamics of radioactive material released into

the environment due to the Fukushima Daiichi
nuclear disaster.
Techniques developed by our project are actually used in environmental radioactive material
monitoring. In particular, a radioactive strontium
rapid analysis system is used in measuring strontium in rainwater accumulated around the contaminated water storage tank at the Fukushima
Daiichi Nuclear Power Plant and the use of a radioactive nuclide mapping system using a portable gamma-ray spectrometer is being considered
for monitoring for environmental recovery.

Project 4

Measurement and Analysis

19

Project 5

Speciation Radiochemistry

01

20

02

03

05

06

04

07

08

［01］Sampling at Nagadoro agricultural pond in Iitate Village ［02］A high-speed continuous centrifugal pump for sampling suspended matters ［03］Radiocaesium
extraction from bound-to-organic fractions by decomposition ［04］Sampling of suspended matters in agricultural water at Ota in Minamisoma City ［05］Laboratory
experiment to study the transfer of radiocaesium from soil/water to rice ［06］Sampling at a reservoir in Nagadoro, Iitate Village ［07］Sampling of agricultural waterusing a submersible pump ［08］An irrigation canal in Ota area, Minamisoma City

Project 5

Speciation Radiochemistry21

Project 5

Speciation Radiochemistry
Research on the Speciation and Behavior
of Environmental Radionuclides for theDevelopment of Efficient Decontamination
Technology

Why Did We Start the Project?

It is crucial to measure radionuclides concentrations
and distributions in the environment to understand their
behavior and potential impacts. However, knowing thetotal amount of radionuclides in an environment is not
suﬃcient to be able to predict their uptake into plants
and animals. The movement of radionuclides in diﬀerent environmental compartments, as well as uptake byplants and animals, varies greatly depending on the speciation of the radionuclides. Speciation refers to the various chemical and physical states in which radionuclides
can exist. Determining the speciation of radionuclides
is necessary to predict their movement and potential effects on environments. We, at the IER, aim to clarify the

How Do We Study?

Speciation research determines the states in whichradionuclides exist, and how speciation inﬂuences their
movement in the environment. For example, radiocaesium in soil is taken up by plants at very diﬀerent
rates depending on the type of clay particles in the soil.
Another example is radiocaesium that is in a dissolved
state in water. It can move great distances and be easily
absorbed into living tissues. In contrast, if the radiocaesium is not dissolved, but instead attached to particles
in lake water, then the particles sink to the bottom
sediments and the release of radiocaesium from theparticle can take a long time. While the radiocaesium is
attached to the particle, it is not available for uptake byplants. Therefore, it is important to ﬁnd where, in which
form, and how much radioactive caesium exists in aparticular environment.
The following explains a speciﬁc research case. To
understand the transfer of radiocaesium into rice, it is22

speciation of radionuclides. Our objective is to advanceresearch by determining how speciation inﬂuences theenvironmental behavior of radionuclides. Understanding
radionuclide speciation is also critical to separation technologies used in radioactive waste management.

(FIG) Chemical speciation of radiocaesium in soil and irrigation water

necessary to take into account the properties of soil andagricultural water. The rate of radiocaesium transfer torice varies greatly depending on the type of soil. For
example, the uptake of radiocaesium is relatively highif the rice is growing in sandy or humic soils. By adding
various chemical solutions to samples of a soil, we candetermine the speciation of the radionuclide and better
predict its bioavailability to rice and other components
in the environment. Water used for agricultural purposescontains both suspended and dissolved components. Radiocaesium is present in both, and knowing its fractional
distribution in the suspended and dissolved states is crit
critical to predicting its movement in the environment. We
are also developing non-destructive techniques for eﬀec
eﬀective removal or immobilization of radionuclides based on
selective separation using a solid-phase extraction systemequipped with molecular recognition capability.

What Did We Find?

Radiocaesium transfer from soil to brown rice can bequantiﬁed by “transfer factor”, deﬁned as the ratio ofradionuclide concentration in the crop to the radionuclide concentration in soil. A transfer factor for rice of
0.001 means that if the concentration of radiocaesium is
1,000 Bq/kg in soil, the amount that would be taken up
by brown rice is only 1 Bq/kg. Radiocaesium existing in
agricultural water is transferred to paddy ﬁelds in both
dissolved and suspended forms. Therefore, to clarify thetransfer of radiocaesium from agricultural water to brown
rice, it is necessary to analyze both forms. The radiocaesium content in the dissolved form can be measured bystraining the water through a ﬁlter with a tiny pore size
(0.45μm). The amount of radiocaesium in the suspended
form requires ﬁltering large amounts of agricultural water(2,000 to 4,000 L) using a high-speed centrifugal pump.
Then the fractions of radiocaesium can be determinedby sequential extraction methods. The transfer factor ofradiocaesium from the dissolved fraction to brown rice
is approximately 10 (1 Bq/L in water results in 10 Bq/
kg in brown rice), which is 10,000 times higher than
the radiocaesium transfer from soil. However, the goodnews is that only small amounts of radiocaesium exist
in the dissolved fraction of agricultural water. Therefore,
the radiocaesium content in brown rice is mainly due

to its uptake fromcontaminated soil,
and that uptake
is low. Uptake ofradioactive iodine
released from the
Fukushima Daiichi
nuclear accident
into plants also
varied depending−
on iodineʼs speciation. It is well-known that iodide (I )−is easily absorbed, whereas iodate (IO3 ) is unlikely tobe absorbed. To better understand the environmental
movement of radioactive iodine, we are studying the useof solid-phase extraction agents for speciation analysis of
iodine in the agricultural waters.

(PIC) An experimental farm ﬁeld in Okuma Town

(PIC) A reservoir in Nagadoro, Iitate Village

How Will the Research Benefit Society?
As explained above, research on speciation of radionuclides is necessary since environmental movement and absorption in living beings and plants
largely vary depending on it.
As an example, the previous section shows thattransfers of radiocaesium to plants from soil andagricultural water depend largely on speciation of
the radionuclide. We are also conducting researchon re-elution of radiocaesium accumulated in thereservoir bottom sediments, and the proportion ofradiocaesium in boar food that is absorbed by theirbody.
Innovative information on the speciation of radionuclides clariﬁes the environment in which aradionuclide is likely to be mobile and thus taken
up by organisms. Such information also clariﬁes inwhich form of radionuclide the transfer can be con-trolled or minimized. Furthermore, we are working
to establish eco-friendly, cost-eﬀective techniques
for selective separation of radionuclides from solutions and soil and to develop an eﬃcient method forradioactive waste remediation.

(PIC) A temporary storage area of contaminated soil in Okuma

Project 5

Speciation Radiochemistry23

Project 6

Modeling

0124

14 March 2011 at 17:00 UTC

15 March 2011 at 04:00 UTC

15 March 2011 at 11:00 UTC

16 March 2011 at 09:00 UTC

02

03

04

05

06

07

［01］An aerial photo of the Paciﬁc ［02］An example of an atmospheric dispersion model calculation result ［03］Presentation at the international academic
conference ［04］An example of a river model calculation result ［05］Joint reservoir investigation with our river/lake project ［06］Explanation of a restoration
plan using a diorama at Okuma Town community center ［07］Discussion of calculation results

Project 6Modeling

25

Project 6

Modeling
Development of Radionuclide Transport Models
for Atmosphere, Forests, Rivers, and Lakes
for Emergency and Long-term Prediction

Why Did We Start the Project?

How are the radioactive materials released as aresult of the Fukushima Daiichi nuclear accident
in March 2011 spreading? What will happen to thereleased radioactivity in Fukushima in the future?
What can happen in terms of contamination levels
under extreme climate conditions such as heavy rain
and strong wind?
All these questions can be answered based on tools
and techniques for predicting transport of radioactive
materials. To accomplish this task, both monitoringand numerical modeling are to be employed.
In the numerical model used, atmospheric dispersion of radioactivity is modelled using mathematicalformulations in an integrated way, which enables deriving time evolution of activity concentration or air
dose rate for any location. The wealth of experience
gained following the Chernobyl accident is available;
however, the Fukushima environment has its own
features and the existing knowledge is not always
suﬃcient to account for the ongoing processes. The
challenging task before our group is: to further develop the models using emerging knowledge after the
Fukushima accident. Based on a newly developed andmore reliable model, we seek to understand the cur-

How Do We Study?

The IER modeling group comprises researchers ofcomplementary backgrounds: members with morethan 30 yearsʼ experience in post-Chernobyl studies
and expertise in radionuclide dynamics and relevantﬁelds, as well as capable young Japanese researchers.
Close cooperation with the IER monitoring group
allows us to incorporate the latest Fukushima data
26

rent radiation situation and predict its development in
the future.
The goals of our group include:
new knowledge about radioactivi1 Collating
ty dispersion in the environmental media of
Fukushima prefecture (air, forests, rivers, andlakes), in cooperation with the IER monitoringgroup, with a view of developing models.

models to predict radioactivity dispersion
2 Usingunder extreme climate conditions on a shorttime scale from several days to several weeks,
as well as long-term transport on a scale of up
to several decades.

models to verify whether the counter3 Using
measures implemented will ensure containmentof environmental contamination and reduceradiation dose for the general public in aﬀected
regions. Our research using numerical calculation models will contribute to the scientiﬁcknowledge required for nuclear emergency
preparedness and development of countermeasures.

into mathematical models. Observations of forests,
rivers, and lakes have been conducted by this groupsince the IER establishment in 2013. Radionuclidetransport models were actively developed for Europe and US based on observational data primarily
after the Chernobyl accident. These models are now
employed to understand transport processes in theFukushima environment based on the current observations and will be further developed in the future.
The models serve to predict, among other things,
spatial and temporal distribution of radioactivity andaddress basically three environmental compartments:
air, forests, and rivers/lakes. Using the atmosphericdispersion model developed by members of our groupprior to the Fukushima accident, inverse modeling
was performed for the processes; e.g., advection,
diﬀusion, dry and wet deposition of radioactive materials released from FDNP. Understanding changes in

What Did We Find?

Another model under development is the forest
transfer model which is a compartment model basedon measurements in the Yamakiya area forest. In
this model the forest is divided into the tree and soil
sections, which are subdivided into compartments;for example, leaves, crowns, branches and roots. Masstransfer ﬂux between the compartments is integrated
over time to estimate activity concentrations in eachcompartment. The model allows prediction of longterm transfer of radioactivity as a function of theforest age.
The model applied to rivers and lakes is the basinmodel of radionuclide water transport. It includes submodels accounting for 1) wash-oﬀ 2) river transportand 3) dispersion in a water body for estimating 2D orthe airborne concentrations of radionuclides and theirdepositions is important to explain the current situation. Use of models also allows us to clarify temporal
spatial distribution of materials for which information
could not be obtained through monitoring in the early stage of the nuclear disaster. There is no questionthat comparison of observational data, measurements
and simulated results will help to improve emergency countermeasures and prediction of radionuclidetransport processes, in particular, in extreme climate
conditions.

3D distributions of radionuclide activity concentrations.
As shown by calculations, the radiocaesium washoﬀ
to rivers during ﬂoods in heavy rains is higher ascompared to Chernobyl because of steeper slopes. At
the same time, radioactivity can be transported along
the river from water reservoirs in highly contaminatedareas (such as evacuation zone) to densely populated
territories. To be able to predict radiocaesiumtransport, with consideration of ﬂoods, a model isbeing developed for water reservoirs upstream of the
Mano River, nearby rivers and the Niida River basin.
These models are expected to provide scientiﬁc data
for assessing eﬀects of decontamination activities forwater reservoirs used for agricultural purposes on
contaminated areas.

How Will the Research Benefit Society?
In the future, we will continue elaboration andveriﬁcation of our models using observational
data. Several avenues for applying our models
can be envisaged: the forest model can be used
to predict radionuclides transfer to wood, whichis essential for revival of the forest industry. The
same model can actually be employed to evaluate
eﬀects of decontamination measures. Likewise,
the rivers/lakes model can be used to identify effective decontamination technique for dry riverbeds and speciﬁcally to help decision-making forrecreational activities on former dry riverbeds.
The rivers/lakes model is useful for predicting

radionuclide transport to downstream basins anddeveloping appropriate mitigation methods. The
atmospheric dispersion model will be applicablein case of a nuclear accident to predict atmospheric transport and resuspension of radioactivity. The lessons learned with respect to modelingfollowing the Fukushima accident are to be madeavailable outside Japan to use in similar emergencies. Just as experience gained after the Chernobyl accident is utilized in Fukushima, we standready to apply elsewhere the knowledge obtainedin Fukushima.

Project 6Modeling

27

Collaborative
Research Institutes
National University Corporation

Fukushima University
Fukushima University, as the only national university situated in the prefecture aﬀected by the Fukushima Daiichi Nuclear
Power Station accident, established Institute of Environmental
Radioactivity (IER) for the purpose of contributing to the local
community through the research activities of elucidating thetransport mechanism of radionuclide in the environment andits impact on ecosystems. The IER, with its unique location
close to the accident-aﬀected areas, pursues research to better

28

understand the long-term eﬀects of radionuclides released into
the environment in Japanʼs temperate and humid climate, in
cooperation with other Japanese and international universities
and research institutes. The IER shares the knowledge acquired
through research activities both domestically and internationally, as well as broadly disseminates the expertise and information required by the aﬀected municipalities.

Environmental Radioactivity Research by Collaborative Research Institutes
National University Corporation

National University Corporation

University of Tsukuba

Hiroshima University

The University of Tsukuba (UoT) will continue the research launched immediately after the accident, including
investigation of radionuclide transport in the environmentof forest and land areas. As part of a joint project, UoT will
participate in model experiments aiming to clarify the radionuclide transport in the rivers and oceans by using a 150
meter-long ﬂume and a wave tank to evaluate the radionuclide behavior under controlled conditions that mimic thenatural environment. Leveraging the analyzed data and themonitoring knowledge, through the collaboration with the
IER as well as other domestic and international institutes,
UoT will further promote the research of radionuclide environmental dynamics, focused on the rivers and forests; joint
implementation of water analysis in compliance with international accuracy standards; joint usage of a database; andthe sharing of techniques to evaluate radionuclide behavior
in the environment.

Hiroshima University, having the best-equipped researchfacility for amphibian biology aﬃliated with a graduate
school, has been investigating radiation eﬀects on animals
and plants as well as experiment data management. Its
research is focused on 1) morphological change of aﬀected
amphibians, 2) genetic analysis to study the eﬀects of a genetic trait, 3) analysis of the impact for the next generation,and 4) wild species (tailed/tailless amphibian) which inhabit the areas around the Fukushima Daiichi Nuclear Power
Plant. Hiroshima University intends to clarify the eﬀects
of acute exposure and of low-dose, long-term exposure andto establish an evaluation system of radiation impact. To
investigate the eﬀect of radionuclides released by the nuclear accident on the plant ecosystems, Hiroshima University
conducts a ﬁeld survey of moss plants in the Fukushima
area and accumulates the survey data on radiation eﬀects
on the organisms in the environment.

National University Corporation

National University Corporation

Nagasaki University

Tokyo University of Marine
Science and Technology

Utilizing the base set up in the Republic of Belarus, Nagasaki University (NU) has been evaluating the dynamics
of environmental radioactivity and clarifying its impact inareas such as Chernobyl and Semipalatinsk nuclear test
site, in collaboration with international institutions suchas IAEA and WHO in Japan and overseas in the ﬁeld ofradiation health risk control. After the nuclear accident,
NU set up a reconstruction promotion base in Kawauchi
village, Fukushima Prefecture, and conducted radiationdose estimation based on the measurement of radiocaesium
concentration in soil, water, and food, as well as evaluationof long-term dynamics of radiocaesium, especially in foods
leveraging the research results. In particular, NU takes partin research on the dynamics of radionuclides based on thefood chain through animals.

Tokyo University of Marine Science and Technology(TUMSAT), utilizing its unique resources in the TUMSAT
Center for Marine Research and Operations, has establisheda framework for conducting radioecological surveys in coastal and oﬀshore areas of Fukushima; the surveys are aimed atclarifying the radiocaesium dynamics of the marine ecosystem. With the continuous monitoring of the spatiotemporalchange of radiocaesium in marine organisms and their environment, researchers are identifying the transfer pathwayof radiocaesium into the food chain, which would aﬀect thedecrease rate of radioactivity in the living bodies of marine
biota. TUMSAT has been conducting survey cruises of theuniversityʼs own research and training vessels, in responseto requests from domestic and overseas researchers and incooperation with collaborative research institutes.

Public University Corporation

Quantum Medical Science Directorate of National Institutes
for Quantum and Radiological Science and Technology

Fukushima Medical University has a university hospital
serving as the center of the medical institution network in
Fukushima Prefecture, including a disaster base hospitalfunction. Since the Fukushima Daiichi nuclear accident,
the university has also played a role as an institution not
only to provide medical care for nuclear accidents, but also
to support general healthcare in the aﬀected areas. Subsequently, the University established the Fukushima Global
Medical Science Center, which includes a department for
estimation of radiation dose to the public. Measurement ofenvironmental radiation for the dose estimation is included
as a part of activities of the department.

Quantum Medical Science Directorate of National Institute of Radiological Sciences utilizes its prior achievements
and human resources related to radioecology to contribute to
the advancement of research on dynamics of radionuclides
in the environment and ecosystems, focusing on ecological
functions such as biogeochemical cycles. It also participatesin the research on the behavior of radionuclides in the environment based on their development of the worldʼs mostadvanced isotope analysis technology for low activity concentrations of radionuclides (e.g., strontium and actinoid).

Fukushima Medical University*In April 2019, National Institute of Radiological Sciences was merged into
Quantum Medical Science Directorate of National Institutes for Quantum
and Radiological Science and Technology.

Collaborative Research Institutes

29

Our Researchers
Rivers and Lakes
Aleksei KONOPLEV （Vice Director）

Specially Appointed Researcher
Project Professor
Doctor of Science【Research Interests】
Chemistry, Radiobiology

Ocean
Hyoe TAKATA

Specially Appointed Researcher
Project Associate Professor
Ph.D. (Fishery Science)【Research Interests】
Marine Chemistry, Chemical Oceanography,
Marine Environmental Radioactivity

Yoshifumi WAKIYAMA
Tenured Researcher
Senior Assistant Professor
Ph.D. (Science)【Research Interests】
Hydrogeomorphology

Yasunori IGARASHI
Specially Appointed Researcher
Project Assistant Professor
Ph.D.

【Research Interests】
Radio-hydrology

Seiki KAWAGOE (Adjunct Researcher)
Professor (Faculty of Symbiotic Systems Science)
Ph.D. (Enviroment Studies)【Research Interests】
Natural Disaster Science, Hydraulic Engineering,
Hydrology

Yoshiyuki YOKOO (Adjunct Researcher)

Associate Professor (Faculty of Symbiotic Systems Science)
Doctor of Philosophy (Engineering)【Research Interests】
Watershed Hydrology, Water Resource Engineering,
River Engineering

Measurement and Analysis
Tatsuo TORIISpecially Appointed Researcher
Project Professor
Ph.D. (Engineering)【Research Interests】
Radiology Measurement, Environmental Radiation,
Atmospheric Electricity

Takayuki TAKAHASHI (Adjunct Researcher)
Professor (Faculty of Symbiotic Systems Science)
Ph.D. (Engineering)【Research Interests】
Robotics, Control Engineering

Katsuhiko YAMAGUCHI (Adjunct Researcher)
Professor (Faculty of Symbiotic Systems Science)
Doctor of Science【Research Interests】
Solid State Physics

Yoshitaka TAKAGAI (Adjunct Researcher)
Professor (Faculty of Symbiotic Systems Science)
Ph.D. (Engineering)【Research Interests】
Analytical Chemistry30

Ecosystems
Kenji NANBA (Director)

Professor (Faculty of Symbiotic Systems Science)
Ph.D.

【Research Interests】
Environmental Microbiology, Microbial Ecology

Vasyl IOSHCHENKO
Tenured Researcher
Professor
Ph.D. (Biology)【Research Interests】
Radioecology

Toshihiro WADA
Tenured Researcher
Associate Professor
Ph.D. (Agriculture)【Research Interests】
Fish Ecology, Fisheries Ecology, Aquatic Radioecology

Hiroko ISHINIWA

Specially Appointed Researcher
Project Assistant Professor
Ph.D.

【Research Interests】
Animal Ecology, Molecular Ecology

Shingo KANEKO（Adjunct Researcher）

Associate Professor (Faculty of Symbiotic Systems Science)
Ph.D.

【Research Interests】
Molecular Ecology, Conservation Genetics,
Conservation Ecology

Thomas HINTON
Visiting Professor
Ph.D. (Radiation Ecology)【Research Interests】
Radioecology

Speciation Radiochemistry
Hirofumi TSUKADA
Tenured Researcher
Professor
Ph.D. (Agricultural Science)【Research Interests】
Environmental Radioecology

Previous-Faculty Members
Beata VARGA

Specially Appointed Researcher
Project Professor (Jan. 2014 - Apl. 2014)
Ph.D. (Physics)【Research Interests】
Analytical Radiochemistry

Stefan BENGTSSON

Ismail Md. Mofizur RAHMAN

Specially Appointed Researcher
Project Assistant Professor (Sep. 2014 - Jul. 2015)
Ph.D. (Agriculture)【Research Interests】
Terrestrial radioecology【Research Interests】
Environmental Analytical Chemistry

Sergii KIVVA

Tenured Researcher
Associate Professor
Ph.D. (Environmental Analytical Chemistry)

Modeling

Specially Appointed Researcher
Project Professor (Feb. 2014 - Nov. 2015)
Ph.D. (Mathematical Cybernetics)【Research Interests】
Computational Methods of Environmental Modeling

Valentin GOLOSOVMark ZHELEZNYAKSpecially Appointed Researcher
Project Professor (Mar. 2014 - Apr. 2016)
Doctor of Sciences【Research Interests】
Environmental Radioactivity, Fluvial Geomorphology【Research Interests】
Environmental Hydrology

Olena PARENIUKSpecially Appointed Researcher
Project Professor
Ph.D.（Fluid Mechanics)

Shigekazu HIRAO
Tenured Researcher
Senior Assistant Professor
Ph.D. (Engineering)【Research Interests】
Environmental Radioactivity

Naoaki SHIBASAKI (Adjunct Researcher)
Professor (Faculty of Symbiotic Systems Science)
Doctor of Science【Research Interests】
Hydrogeology, Groundwater Basin Management,
Applied Geology

Specially Appointed Researcher
Project Assistant Professor (Apr. 2014 - Apr. 2016)
Ph.D. (Radiobiology)【Research Interests】
Radiobiology

Alan CRESSWELL

Specially Appointed Researcher
Project Associate Professor (Sep. 2014 - May 2016)
Ph.D. (Nuclear Structure Physics)【Research Interests】
Radiation Measurement Technology

Kei OKUDA

Specially Appointed Researcher
Project Assistant Professor (Apr. 2014 - Mar. 2017)
Ph.D. (Agriculture)【Research Interests】
Wildlife Management, Wildlife Ecology, Radioecology

Akira WATANABE (Adjunct Researcher)

Project Professor (Aug.2013 - Mar.2018)(Faculty of Symbiotic Systems Science)
Doctor of Science【Research Interests】
Geophysics (Meteorology)

Michio AOYAMA

Specially Appointed Researcher
Professor（with Fixed Term) (Feb.2014 - Mar.2019)
Doctor of Science【Research Interests】
Geochemistry, Oceanography, Environmental Radioactivity

Tsugiko TAKASESpecially Appointed Researcher
Project Associate Professor (Apr.2014 - Mar.2020)
Doctor of Science【Research Interests】
Chemical Physics

Our Researchers

31

Access
Sendai Miyagi
IC

Fukushima
To Sendai

4

4

115
Tohoku Shinkansen

Fushiogami
Intersection

MinamiFukushima

Kanayagawa

To the center ofFukushima city

To Koriyama

Koriyama

Koriyama
IC

114

Bus stopTo
Nihonmatsu
city

E

4

To Iwaki

To Inawashiro and Aizuwakamatsu

Campus Map

114

S

Tohoku Honsen Line

Tohoku Expressway

Fukushimanishi IC

N

Fukushimanishi ICW

To Yonezawa

13

Sendai

N
E

W

Tokyo

316

Mito
P

S

Institute ofEnvironmental
Radioactivity

P

P

P

To Fukushima
and Sendai

Kanayagawa 1, Fukushima City, Fukushima Prefecture, 960-1296
Phone 024-504-2114 Fax 024-503-2921 E-mail ier@adb.fukushima-u.ac.jp
http://www.ier.fukushima-u.ac.jp/

convenience store

To Koriyama and Tokyo
Kanayagawa

August 2020