CHERNOBYL FORESTS:
MAJOR PROBLEMS AND CONCERNS
Vasyl Yoschenko
UIAR NUBiP of Ukraine
vasyl@uiar.kiev.ua

Seminar at University of Tsukuba, 2 Nov 2013

Good afternoon, dear colleagues.

I’m Vasyl Yoschenko from Ukrainian

Institute of Agricultural Radiology. First of all, I would like to thank you forthe invitation to visit your country and the warm welcome here. I have toadmit that during this research year we visited many industrial sites and seen
the impressive results of agriculture scientists.

In general we hope verymuch that we will have the collaboration in [Unclear]. Valery Kashparov…

1

Radioactive contamination after Chernobyl and Fukushima
Chernobyl and Fukushima
accidents:• close levels of contamination
with radiocesium and close
areas affected

Japan and Chernobyl zone:

137Cs, kBq/m2• approx 2/3 of the territories
are covered with forests

Differences between the
two accidents / areas
affected:• presence of the fuelcomponent radionuclides (90Sr,
TUE etc) in CEZ• landscape
Seminar at University of Tsukuba, 2 Nov 2013

Valery Kashparov presented the situation in forest in Ukraine in general. In
my presentation I will concentrate on the most contaminated part of the acuteterritory [Unclear] contaminated territory in Ukraine between the 30
kilometer Chernobyl zone.
First, I’d like to show you this map, is the map of Chernobyl affected area andthis is Fukushima affected area.
These are the maps in same special scale.
You can see in general the territory affected by the Fukushima accident issmaller than the territory affected by Chernobyl and the levels ofcontaminations in Fukushima are lower but we can say that these are more orless of the same magnitude.
Both for Japan and for Chernobyl zone approximately more than 60,000[Unclear] territories are covered as well as the forest are important and andthere are, of course, some differences [Unclear] in case of Chernobyl presenceof strontium and transuranium elements in the release.
And second is different landscape. In Chernobyl, normally, we have the flat
landscapes and here [Unclear].

2

Radioactive contaminated Chernobyl forests: major concerns
Forest ecosystems in CEZ still remain the
depots of radionuclides. Major concerns:
Done after the accident:- Ways of exposure of public and personnelof CEZ from the radionuclides localized in
the ecosystems- external irradiation- consumption of mushrooms, berries, game …
- utilization of the contaminated wood- radionuclides migration (atmospheric transport,
groundwater) from CEZ- Effects to biota in the ecosystems

Evacuation of public from CEZ
Prohibition of consumption
Prohibition of any commercial activity in
CEZ, including forestry
To be done:
To assess the possible impacts of thewildland fires
To assess the radionuclide distributions
and fluxes in/from the forests
To identify effects of radiation to thespecies (ecosystems)

Seminar at University of Tsukuba, 2 Nov 2013

So the forest in Chernobyl exclusion zone will remain for the long time thedepots of radionuclides because we don’t make any decontamination.
And in this case we have to think about possible exposure to public andpersonnel along with various other exposure and…
[Unclear] zone we can – in general for the contaminated forest the [Unclear]
possible impacts on population we imagine of exposures.
We can especially for the [Unclear] zone another consignment [ph] is possible
migration of radionuclides localized in this territory to other territories of
Ukraine.
Again, if these ecosystems are contaminated we have to think about thepossible effects of biota to wild [Unclear].
For exposure of population as Dr. Kashparov said, it can be profound because
we evacuated public from the exclusion zone.
And to address these provisions we performed special experiments, evaluate…

3

Wildland fires: the problem
Wildland fires frequency (average)
Numberof fires

Area burnt,
ha yr-1

Frequency,
km-2 yr-1

Ukraine

3866

3927

6.4⋅10-3

increased frequency – 42-116 fires per
year, or (2-5.7) ⋅10-2 km-2 yr-1;

Japan

3274

2311

8.7⋅10-3

increased severity of fires – up to
average of 80 ha per fire in 1992

2001-2003,
Zibtsev, 2002
1990-1999,
Forestry Agency
Japan, 2000

Chernobyl Exclusion zone:

Wildland fires impacts:

Fires, 1992

• radioecological – radioactivity redistribution(resuspended amounts and transportation rangeof the radionuclides);Dry windy
weather,1991

Dry windy
weather,1989• radiological – doses to the firefighters andpopulation (airborne concentrations, dispersal
composition, solubility etc);• social (awareness of the authorities andpopulation concerning the actual potential
consequences of the fires)

NOAA, 08 May 2003, 18:30,

Seminar at University of Tsukuba, 2 Nov 2013 by UCLRMFirst, one of the possible ways of radionuclides migration from the exclusionzone can be forest fire, wildland fire.
And in this I used the data for Japan which I found in the Internet and I canshow that, in general, the number of fires per year and the average burnt area
in Japan, in Ukraine are almost the same [Unclear] territory.
I don’t know if this is important for Japan but it can be important for us.
Also after abandoning of the exclusion zone the number of frequency of fires
and the severity of fires rise in the Chernobyl exclusion zone.
I hope you can see this green line, shows airborne concentration ofradionuclides in Chernobyl during the fire.

It exceeds the concentration

during the dust storms and during the normal weather.
This is for Chernobyl zone. People in here for example mentioned about thepossible impact on their health from the fires at Chernobyl.
There is some background to say about that. As you can see this is a satellite
image of the fire which is localized here. This is in west part of – to the westof the exclusion zone and this is here. This whole blue [Unclear].

4

Wildland fires: experimental studies
Forest fire experiment

Seminar at University of Tsukuba, 2 Nov 2013

In order to determine what is really the danger of the fires we make theexperiments control points of the [Unclear] in the exclusion zone.
So firstly, this is a forest, this one. Firstly…
…it’s on the research and equipment [Unclear] matters.

5

Wildland fires: experimental studies
Wildland fire experiments: Radionuclide airborne concentrations along the plumeaxis at the 1-m height above the ground surface
Grassland #2

Grassland #1
10

AV

AV

10

1

1
0.1

0.1
-50

0

Х, m

50

100

0.01
-50

0

50

100

150

200

X, m

Forest1.6

137Cs, Bq m-3

AV

1.2

90Sr, Bq m-3

238Pu, mBq m-3

0.8

239+240Pu, mBq m-3

0.4
0
0

50

100

150

200

250

300

350

400

Х, m

Besides the values of the radionuclide airborne concentrations, these data show
the ranges of their transportation during the fires
Seminar at University of Tsukuba, 2 Nov 2013

In this way we can manage the concentrations of different radionuclides, andthe various distances from the social human beings and [Unclear] for forest
fire here.

There have been concentration of cesium, for example, is also

mainly the various [Unclear]. Another interesting point here is a range of
spreading of the plume.
In general, the public awareness several hundred meters.

6

Wildland fires: experimental studies
Wildland fire experiments: Radionuclide resuspension factors, m-1
Calculated for

137Cs

90Sr

238Pu

239+240Pu

Grassland fire, #1
Activity in fuel material (1.7±0.2)⋅10-5 (1.5±0.2)⋅10-5 (3.5±1.0)⋅10-7
Total activity(1.7±0.2)⋅10-7 (3.7±0.5)⋅10-7 (4.9±1.4)⋅10-9(2.4±0.6)⋅10-7(3.8±0.9)⋅10-9

Grassland fire, #2
Activity in fuel material (8.0±4.8)⋅10-6 (4.4±2.6)⋅10-6 (2.9±2.3)⋅10-6
Total activity(1.9±1.1)⋅10-7 (1.8±1.5)⋅10-7 (1.3±1.0)⋅10-8(2.6±2.1)⋅10-6(1.3±1.0)⋅10-8

Forest fire, #3
Activity in litter(7.0±2.8)·10-7 (1.2±0.5)·10-6 (1.2±0.8)·10-6(9.4±5.2)·10-7

Activity in fuel material (4.7±2.0)·10-7 (3.5±1.6)·10-7 (1.1±0.7)·10-6(8.3±4.8)·10-7

Total activity(4.7±2.0)·10-8 (1.1±0.5)·10-7 (3.2±2.2)·10-8(2.5±1.6)·10-8

These data (at least orders of magnitude) can be used to estimate theradionuclides resuspension during other wildland fires
Seminar at University of Tsukuba, 2 Nov 2013

Also we determined the resuspension factors and other parameters whichcharacterize distribution of radionuclides during the fires.

7

Wildland fires: experimental studies
Wildland fire experiments: Doses to the firefighters (1 hr exposure, conservative
scenario; for inhalation – 50 yr effective equivalent dose)
Maximum airborne
concentration, Bq m-3, inthe site
137Cs

90Sr

238Pu

#1

#2

#3

5

1

0.27

3

0.5

0.33

Dose, µSv, in the site

Way ofexposure

#1

#2

#3

External fromthe cloud

6.9⋅10-4

1.4⋅10-4

3.7·10-5

Inhalation

6⋅10-2

1.2⋅10-2

3.2·10-3

External fromthe cloud10-4

1.7⋅10-5

1.1·10-5

Inhalation

0.24

4.1⋅10-2

2.6·10-2

Inhalation

7.1

0.53

1

3.4⋅10-3 2.5⋅10-4 4.6·10-4

Inhalation

17

1.3

2.8

External irradiation from soil and vegetation

16

10

4.2

Total dose

40

12

8

239+240Pu 6.7⋅10-3

5.1⋅10-4

1.1·10-3

Seminar at University of Tsukuba, 2 Nov 2013This is really [Unclear] of the dose in especially to fireman calculated for thevery conservative scenario that this fireman stands in the most contaminatedpoint.
These are exposure during 1 hour and we’ve calculated here effective
equivalent dose. Now the important information here is for this another caseand internal doses can be equal or even exceed the doses from external
inhalation during the same period. We think this is from inhalation and thetotal dose is say external is 60 and the total [Unclear].
But this is because of inhalation of plutonium by the dose, and cesium andstrontium did other smoke…

8

Wildland fires: modeling the transport process
Plume from thevirtual point source(Gauss model)

Virtual point
source ofreleaseZ

Normaldistribution of
the aerosol
concentration
X0

Actual sourceof release

X(Zmax)

Initial plume rise
(special model
designed)

Seminar at University of Tsukuba, 2 Nov 2013

We’ve made some modeling exercise and the modeling…

9

X

Wildland fires: modeling the transport process

100

0.1

10

0.01
model

model

Wildland fire experiments: Results of the modeling exercises. Forest fire1

0.1

0.00010.01
0.01

0.00001
0.00001

0.1

1

10

100

Radionuclide releases
during the fires,

0.001

0.0001experiment100% of activity in fuelmaterial (abovegroundbiomass + litter)

0.1

1

model

model

0.01

0.1

10

1

0.1

0.01
0.01

0.001
experiment

0.001
0.00010.1

1experiment

10

100

137Cs

90Sr

Grass
#1

0.06

0.15 0.03

Grass
#2

0.14

0.15 0.07

Forest

4.2

2.9

0.01

0.00001
0.00001

0.0001

0.001

0.01

0.1

experiment

1

ΣPu

0.8

Seminar at University of Tsukuba, 2 Nov 2013

In this right here, conduct this experiment and calculate the data and we didit among the activities, the percent of activity which was reduced in the firefrom the burned, from the above-ground biomass and litter.
Forest fires and some parts of [Unclear].

10

Wildland fires: conclusions
Local scale surface fires:- no any significant redistribution of radioactivity- impacted area: some hundreds meters- critical group of personnel: firefighters- doses to the critical group: low doses; significant contribution of internal radiation due
to inhalation of TUE
Large fires (modeled scenario – all critical forest stands in CEZ burn simultaneously):- no any significant redistribution of radioactivity from CEZ- no any significant additional doses to the personnel in CEZ and population outside CEZ
To be able to assess the potential impacts of the fires we have to know (in addition to
the fire intensity, weather parameters etc):- radionuclide fractions in the aboveground biomass (distribution in the forests)- fraction of radionuclides released from the burning biomass
Seminar at University of Tsukuba, 2 Nov 2013

That’s the conclusion and here I’ve assumed…
Important thing here is that to be able to assess the potential impact of forest
fires we have to know the fractions of radionuclides in the abovegroundbiomass.

11

Forest ecosystems: radionuclides distributions and fluxes
Natural ecosystem: 40 y.o. pine forest(Scots pine)

Semi-natural ecosystem: 20 y.o.
plantations at the Red Forest storage site
(Scots pine and birch)

Seminar at University of Tsukuba, 2 Nov 2013

[Unclear] we did extensive activities about the radionuclides distribution in theforest ecosystem. We performed extensive activities [Unclear] radionuclides
distribution and fluxes in the forest ecosystem.
Our results from [Unclear] ecosystem one is, the pine tree growth in theexperiment is 40 years of pine forest
Another is semi-natural ecosystem. This is plantation of Scots pine and birch
and they’re here in the territory of the Red Forest.

12Forest ecosystems: radionuclides distribution
Semi-natural ecosystem (Red Forest):
Scots pine

Birch
100%

137

Biomass

Cs
IN

137

Cs
OUT

90

Sr
IN

90

Sr
OUT

80%

0%

Leaves60%

10%

TwiggsBranches

20%
30%
40%
50%
60%
70%
80%

Wood
Inner bark40%

Outer bark
Branches
Twiggs.
Needles > 1

20%

Needles 1

100%

Outer bark
Inner bark
Wood

0%
Biomass

90%

90

Sr

137

Cs

80%

Leaves100%

Twiggs60%

Branches

40%

Outer bark
Inner bark

20%

Wood

0%
Biomass

90

Sr

137

Cs

Seminar at University of Tsukuba, 2 Nov 2013

In the Red Forest, we have our main experimental site and as always Dr.
Kashparov was at site.
In Red Forest you can see the distribution of radionuclides in different
compartments of the leaves, of the above-ground biomass.
Here, what’s strange [ph] for example, was cesium.

13Forest ecosystems: radionuclides distribution
Natural ecosystem, pine forest:

100%

100%

80%

80%

Needles 1 y
Needles > 1 y

60%

Biomass

60%

TwiggsLitterSoil

40%

Branches
Outer bark40%

Inner bark
20%

Wood

20%

0%

0%
137Cs

90Sr

238-240Pu

Biomass

137Cs

90Sr

Seminar at University of Tsukuba, 2 Nov 2013

And the same is for the natural ecosystem.
[Unclear] weather here, with first season, the total activity in abovegroundbiomass is say 5% of the total activity in the ecosystem. This is much lower
than normally in Japan forest fire outside [Unclear].
But there is big problem with strontium in pine tree because its total content
in the above-ground biomass can be [Unclear] of the total [Unclear] in theecosystem.

14

Forest ecosystems: definition of the radionuclide fluxes

R, requirement or incorporation, is the total activity of radionuclide mobilized by the current
production of biomass

R=Σ ∆Mi×Ci∆Mi - the annual increments of the tree’s elements

Ci - the radionuclide specific activity in the element at the end of the growing season
i = needles, twigs, branches, wood and bark.
U, uptake, is the radionuclide activity taken from the soil by the root system

U=Σ Immobilizationi + Σ Returnj ± ∆f

i = wood, branches, barkj = litterfall, throughfall∆f - changes of the radionuclide activity due to variations in the needles biomass.
T, internal transfer, is a sum of the radionuclide fluxes from senescing tree parts to support new
biomass production

Tneedles=∆Mlitter× (Cneedles1-Clitter) – throughfall
Tbranches=∆Mbranches× (Ctwigs-Cbranches)
Tbark=∆Mbark× (Cinner bark –Couter bark)

Seminar at University of Tsukuba, 2 Nov 2013

We were once approached to determine the radionuclides once it’s [ph] in theecosystem [Unclear].
Male Participant
Can you please repeat?
Dr. Vasyl Yoschenko
We were once approached to determine to recognize [ph] the radionuclides
cycle in the ecosystem.

15

Forest ecosystems: modeling the RN transfers

IAEA BIOMASS, 2002

MATPASS (UIAR NUBiP)Interaction matrix for 137Cs in forests (IAEA BIOMASS, 2002)
Seminar at University of Tsukuba, 2 Nov 2013

We were just finishing [Unclear].
The IAEA in the [Unclear] biomass group recommends the interaction matrix
for cesium in forest.
There is a lot of compartments with different relations between them. But it
was too complicated and we [Unclear] we created [Unclear] MATPASS which isless complicated but the main part present here is the uptake from the total
biomass and especially the renewable mass, translocation between these twocomponents depend on the litter and soil and also depend in the ground and[Unclear] particles which is not from Japan.

And the soil is basically several

layers with different geochemical [ph] factors.

16

Semi-natural forest ecosystem: radionuclides fluxes (2005)
Radionuclide annual fluxes in Red Forest (Scots pine plantation, 3300 trees ha-1):
137Cs

90Sr

GBq ha-1 y-1

Fluxes

OUT

IN

OUT

IN

Incorporation

0.67

1.13

4.6

22.9

Uptake (1+2+3)

0.3

0.36

7.6

37.5

(1) immobilization

0.05

0.06

1.97

11.0

(2) return to soil

0.21

0.24

5.56

26.1

(3) ∆f

0.04

0.06

0.11

Internal transfer

0.39

0.8

-2.95

0.4

-15.9

ARE THESE FLUXES BIG?
Total activities in the studied trench: 137Cs ~ 600 GBq, 90Sr ~ 290 GBq
Total activities in the trees biomass at the trench: 137Cs ~ 0.024%, 90Sr ~ 2.52% of theradionuclides inventories in the trench
Annual uptake fluxes: 137Cs ~ 0.0038%, 90Sr ~ 0.82% of the radionuclides inventories in the
trenchSeminar at University of Tsukuba, 2 Nov 2013

Here are the reference of the flux estimations for Scots pine. It refers to thetotal values of uptake of radionuclides from soil and we have to [Unclear].
Comparing to the radionuclides contents in the trench for various trees [ph]cesium in the ground biomass is a small number, but for strontium that is
2.5%.
Although uptake flux of cesium is small but for strontium this is almost 1% of
the total content in the trench.

17

Semi-natural forest ecosystem: radionuclides fluxes (2005)
ARE THESE FLUXES BIG?
Total activities in the trees biomass at the trench: 137Cs ~ 0.024%, 90Sr ~ 2.52% of theradionuclides inventories in the trench
Annual uptake fluxes: 137Cs ~ 0.0038%, 90Sr ~ 0.82% of the radionuclides inventories in the
trench137Cs migration from the

90Sr migration from the trench into aquifer

trench into aquifer:

Specific activities of 137Cs inaquifer are 3-5 orders ofmagnitude lower than thoseof 90Sr (up to 0.n Bq L-1)
Biogenic migration of 137Cs
can be more intensive thanits geochemical migration
Till 2001, (7±5)% of the 90Sr initial inventory had migrated
from the trench into aquifer
Seminar at University of Tsukuba, 2 Nov 2013

Comparing to the migration [Unclear] migration from the trench the basevalues for strontium are even bigger because during the 15 years there is
migration order of several percents so it is – this one is bigger.

18

Natural forest ecosystem: radionuclides fluxes (2002)
137Cs

FluxesIncorporation

90Sr

MBq ha-1 y-1
390

Uptake (1+2+3)

1115

129

1063

(1) immobilization

20

294

(2) return to soil

75

753

(3) ∆f34

16

Internal transfer

301

-213

ARE THESE FLUXES BIG?
Annual uptake fluxes: 137Cs ~ 0.67%, 90Sr ~ 5.6% of the radionuclides inventories in theecosystem
Annual geochemical migration fluxes: conservative estimate for typical ecosystems in CEZ~ 0.1%

Seminar at University of Tsukuba, 2 Nov 2013

Also biogenic migration of cesium can be more intensive than its geochemical
migration. And also…
For the natural ecosystems, the annual uptake fluxes can be some percents,
up to 1% of the total radionuclides inventory in the ecosystem and several
percent for strontium.
While the geochemical migration on the ecosystem – on the typical ecosystemin the Chernobyl exclusion zone are much lower.

19

Forest ecosystems, radionuclides distribution and fluxes: conclusions
Natural ecosystems:- significant amounts of 90Sr are localized in the aboveground biomass, and for 137Cs and
TUE these amounts are much lower (forests in CEZ!)- annual uptake fluxes can reach n % and 0.n % of the 90Sr and 137Cs total inventories inthe ecosystem, respectively- geochemical migration fluxes are lower than biogenic migration fluxes- modeling results: biogenic and geochemical fluxes (uptake of radionuclides byvegetation) together form the radionuclides cycling in the ecosystem; uptake ofradionuclides by plants is a significant factor determining the radionuclides vertical
distribution in soil profile and decreasing their downward migration rates
Semi-natural ecosystems:- biogenic and geochemical fluxes of radionuclides are close- radionuclides from the deep soil layers are not involved into the cycling and canmigrate to the groundwater

Seminar at University of Tsukuba, 2 Nov 2013

Just my conclusion that biogenic fluxes play a very important role in theformation of cycling of radionuclides in the ecosystem.

20

Contamination of the Chernobyl zone and effects of acute irradiation

Seminar at University of Tsukuba, 2 Nov 2013

The last part of my presentation is around the effects of radiation to biota.
So in this map of contamination you can see the heavy contaminated part of
the 70 kilometer zone.
For this part, up on the accident, this is the same part. And…

21

Effects of acute external irradiation: Red Forest

Zones of damages to theconiferous species (by Kozubov
and Taskaev, 2002)

Seminar at University of Tsukuba, 2 Nov 2013This is very near from the Chernobyl accident.
Chernobyl atmosphere and here is Red Forest and here are some other placesin Chernobyl.
These two zones are the zones of the level effects to the coniferous species[Unclear] pine species.
Due to acute irradiation in this area [Unclear].
This is the Red Forest after the trees were dried and cut.

22

Effects of radiation: non-human biota in the radiation protection system
The approaches to the radiation protection of biota must be
developed (active contributors: EMRAS BWG of IAEA, 5th Committeeof ICRP …) taking into account: biodiversity (various ways of irradiation and doses to the organisms in thesame ecosystem, various life spans of species, various radiosensitivity etc)
 relations in the ecosystems (roles of certain species in the ecosystem,
evolution of the irradiated ecosystem …)
 final aims of the biota protection (what must be protected – individualorganisms, populations, ecosystems? how to protect? …)
Current approach (ICRP…):
 for typical ecosystems (terrestrial, freshwater, marine) the referent
animals and plants (RAPs) are selected radiation effects are estimated for RAPs and then for the wholeecosystem through application of the risk quotients
Example – ERICA Tool
Seminar at University of Tsukuba, 2 Nov 2013

PASS

23

Non-human biota in the radiation protection system
RAPs (ICRP Publ. 103, ERICA Tool):Freshwater

MarineTerrestrial

Amphibian (frog)

Bird (duck)

Amphibian (frog)

Benthic fish

Benthic fish (flat fish)

Bird (duck)

Bird (duck)

Bivalve mollusc

Bird egg (duck egg)

Bivalve mollusc

Crustacean (crab)

Detritivorous invertebrate

Crustacean

Macroalgae (brown seaweed)

Flying insects (bee)Gastropod

MammalGastropod

Insect larvae

Pelagic fish

Grasses and herbs (wildgrass)

MammalPhytoplankton

Lichen and bryophytes

Pelagic fish (salmonid/trout)

Polychaete worm

Mammal (rat, deer)

Phytoplankton

ReptileReptileVascular plant

Sea anemones/true corals

Shrub

Zooplankton

Vascular plant

Soil invertebrate (worm)(earthworm)

Zooplankton

Tree (pine tree)

Seminar at University of Tsukuba, 2 Nov 2013

To characterize in general, [Unclear] effects to biota, the IAEA and ICRP andother international organization recommended approach by doing the referent
selection.
For terrestrial this is [Unclear] from the [Unclear] tree, for pine tree, forshrubs and for grass and herbs.

24Effects of radiation to Scots pine: chronic irradiation, 1990-2000

Exposures: external and internal
By Kozubov and Taskaev, 2002
Seminar at University of Tsukuba, 2 Nov 2013

After the establishment of the new plantation in the Red Forest in the earlyclearing we had the numerous kinds of morphological changes in the trees.

25Effects of radiation to Scots pine: chronic irradiation, after 2005 (UIAR)
Typical morphological changes: cancelling the apical dominance, suppressing the trees’ growthExperimental array: more than 1100 pine trees
For each tree the morphological characteristics and dose rates from external sources and fromincorporated radionuclides were determined
Seminar at University of Tsukuba, 2 Nov 2013This is [Unclear].
And now if you travel back the changes [Unclear] mainly are on this site.
Normally pine tree has one trunk, and then every year one trunk.
But in some cases the apical dominance is cancelled [Unclear] center of plant
and also is dominant the trees.
We implemented more than 1100 pine trees.
For each tree we determine the morphological characteristics and the different
doses.

26

Effects of radiation to biota
Cytological studies at the experimental array of Pinus sylvestris
Sub-array: several trees of the experimental array which represent various dose rates
Tissues and methods:
meristem of the seed germs(direct counting the DNA aberrations)apical meristem(single cell gel electrophoresis)

Seminar at University of Tsukuba, 2 Nov 2013This is the database we made from this.
We applied also the morphological experiments, we applied some cytogenetics
to this.

We did some DNA aberration methods and by single-cellelectrophoresis.

27Effects of radiation: dosimetry

Calculation of the dose rates to Pinus sylvestris
Target organ: dominant bud
Source of radiation: incorporated RN
The model takes into account:

β-emission of incorporated RNactual distribution of RN in tree’s organs anddynamics of their specific activities in each organ
during a year

shape, location and growing of the organs during ayear (changing geometry of irradiation)

integration of the microdosimetric functions of
the point sources localized in the target organutilization of the microdosimetric functions andgeometrical factors of irradiation of the selected
point in the target organ by RN incorporated inother organs

Principal approach:Seminar at University of Tsukuba, 2 Nov 2013

We also have a look at the dosimetry model we just put up for this especiallybecause the, for example, ERICA tool use just a tree will be different [Unclear]others geometry of the trees.

28Effects of radiation : dosimetry

Dose coefficients for incorporated RN for Pinus sylvestris, µGy h-1 (Bq kg-1)-1

RN

ERICA Tool

Our model

137Cs

3.2×10-4

2.1×10-3

90Sr

6.5×10-4

7.1 ×10-4

Reason of discrepancy: ERICA Tool does not take into account the actual RN
distribution and their activities dynamics.
Also, ERICA Tool operates with the “tree” and does not specify the target organ.

Seminar at University of Tsukuba, 2 Nov 2013

The dose coefficients of that comparing ERICA to our model are different
because we take into account the radionuclide dynamics during the year andvalues of the trees.
Also we select the [Unclear].

29Effects of chronic radiation to Scots pine: dose-effect curves
Morphological changes

Cytogenetic effects
DNA aberrations in seed germs•

ε (D )

1.0

trees with morphoses
50

0.8
40

aberration f requency, %

0.6
0.4
0.2
0.0
0

2

4

•

6

8

10

30

20

10

D, Gy y −1
0

ERICA Tool screening value of 10 µGy hr-1
corresponds to the morphoses frequency of
32%.
This dose rate in our experimental array occurs at
the soil contamination levels of approx 10 kBq kg-1
of 137Cs and 5 kBq kg-1 of 90Sr.

0

2

4

6

8

dose rate, Gy yr-1

Fraction of heavy damaged nuclei in apical meristem
1.0
0.8

effect

EDR10 ≈ 0.008 Gy y-1 ≈ 0.9 µGy hr-1
EDR50 ≈ 0.35 Gy y-1 ≈ 40 µGy hr-1

60
70
80

0.6
0.4
0.2
0.0
0

1

2

3

4

5

6

7

8

dose rate, Gy y-1

According to ERICA Tool, for 137Cs contamination
only, it corresponds to ~ 70 kBq kg-1 soil, d.w.
Seminar at University of Tsukuba, 2 Nov 2013

We might factor that [Unclear]
Thus in this way we obtained the dosing factor, the morphological change andthe cytogenetic change.
This is important that now [Unclear] screening value is for direct [Unclear] ison your left hand microgray per hour which seems to be same but…
…but in our case, for our ecosystem it was [Unclear] ecological change in each
Scots tree.

30

Other species damaged? (UIAR, 2011)
Cytogenetic effects in Evening primrose (Oenothera Biennis L.)
1mean TailDNA, %

0.9
0.8
0.7
0.6
0.5
0.4
0

20

40
DR, µGr h-1

6080

Seminar at University of Tsukuba, 2 Nov 2013

And also there are some other species.
We demonstrate the kind of cytogenetic change in the dose rate.
By the way, I saw this grass yesterday at one of the site near Fukushima site.

31Effects of radiation to biota: conclusions- in CEZ the effects of acute and chronic radiation have been observed in the terrestrial
ecosystems both at the morphological and cytological levels during the whole post-accidental
period (till now);- for the most sensitive plant species in CEZ, Scots pine, chronic radiation leads to formation of
the numerous morphological changes and to the significant suppression of the plants
development at the dose rates thought to be ‘safe’ for the terrestrial ecosystem. In the sametime, this species is a principal one for the most forests in the zone;- apparent rate of morphological changes at the ‘safe’ dose rate level shows also a need for thefurther acquiring the empirical data on the radiation effects in order to build up the radiation
protection system for non-human biota. Collaborative efforts of Ukrainian and Japanese
researchers can be very fruitful;- possible fate of the ecosystems at the radioactive contaminated territories needs evaluation. In
this concern, the special case is the ecosystems at the territories of the sub-surface storages ofradioactive materials (such as Red Forest in CEZ)

Seminar at University of Tsukuba, 2 Nov 2013

I already spoke a lot so from here I will speak to the conclusions because it iswhat our [Unclear] it is important I believe that in collaborative research we
can introduce reliable system of radiation protection of biota.

32

Our publications

Seminar at University of Tsukuba, 2 Nov 2013

We’ve published – this is our publication.

33СПАСИБО ЗА ВНИМАНИЕ!

ありがとうございましたSeminar at University of Tsukuba, 2 Nov 2013

Thank you very much.

34

質 疑
Dr. Vasyl Yoschenko
Well as I told you that we included in our experimental analysis of treatment
with 1100 trees. Approximately 600 of this were selected as Red Forest area
and we had frontal [ph] site outside the exclusion zone with 100 trees andthere other trees are selected on the west dominated areas of the exclusion
zone.
[Japanese]
Dr. Vasyl Yoschenko
But we observe the increased effect of morphological changes requisite evenas the territory is less contaminated territories than in the Red Forest.
[Japanese]
Male ParticipantYeah. I want to know because Red Forest area is the right areas but very
famous place is trench experiment site. Trench site, I think, is a small area
but your study site is outside of trench inside the Red Forest area, yeah?
Dr. Vasyl Yoschenko
Well, our study site in [Unclear] was trench and some adjacent territory. Thisadjacent territory [Unclear].

Red Forest is very convenient site for us

because in the trench we have very contaminated material contained. Withthe trenches this is much less contaminated, so we have almost the same
conditions, almost the same trees, but at the site at very different dose rates.
Inside the Red Forest those [Unclear] pine tree. Those rates [Unclear] to thetrees and this I forgot to tell that this low rates are caused mainly by the root
uptake of strontium-90.
Male Participant
So in the trench area, outside the trench area contamination level is not so
different?

35Dr. Vasyl Yoschenko
It’s much lower. Because the history of this site and of the forest 40 years oldpine forest. The first cloud of the explosion passed through this territory andthe [Unclear]. And those are autumn of 1986, the green pine trees become
red and as such this place got the name, Red Forest. Then the trees were cut
and above this top soil was bulldozed in the trenches. This is the territory say
2 kilometer by 2 kilometer and then there are about 200 trenches in thisterritory. In general in the whole exclusion zone remember there are 800
such trenches. This is not the same, not the right kind for the [Unclear].
Male Participant
Thank you very much.
Male Participant
Thank you very much and I have two questions and first one is on the same as
before. Most of the radiation took for the pine seedlings is coming from theinternal dose mainly from the strontium-90, am I right?
Dr. Vasyl Yoschenko
Yes.
Male Participant
So the external dose is negligible in that area?
Dr. Vasyl Yoschenko
For the Red Forest, strontium-90 is more than 90% of the total – not totalinternal but the whole total. For the less contaminated territories, especiallysomewhere as [Unclear] models of the exclusion zone, the ratio can bedifferent and the external radiation could be suddenly like half of the totalgroup.
Male Participant
But the total dose is quite lower than the contaminated area?
Dr. Vasyl Yoschenko
Yes.
36

Male ParticipantOkay. Thank you. The second one is about forest fire experiment. Did you
find any difference of the chemical or physical form between the cesium andplutonium? Are they included in the same particles in air or different in air?
Dr. Vasyl Yoschenko
Unfortunately I don’t have the trends here but we measured the dispersal
composition of various radionuclides in air.

It’s clear that, for example, forthe forest fire cesium is transferred with vapor [ph] and water groups and[Unclear] deposit material [Unclear]. There are some parts in this of ash
zone but for plutonium the general rule is that it metabolize is associated withfiner particles, than cesium and especially strontium. Strontium was reduced
from the biomass and plutonium was mainly released from litter, maybe evenfrom litter in the case that because the particles are lower and again we don’t
want as much plutonium in the biomass.
Male Participant
If we see the composition of the radionuclides in air, does the change depends
on the distance from the fire place?
Dr. Vasyl Yoschenko
Yes, also there is dependence on radiation.
Male Participant
If we compare it between cesium and the plutonium, which element will go
farther?
Dr. Vasyl Yoschenko
Here, this is one concentration of [Unclear] nuclides plutonium [Unclear] for
one grass on fire it was almost the same.

Here for another grass on fire, we

had the decrease of cesium and strontium in the spot.

Total volume ofdeposition was in the more distant area [Unclear] which means that there
were fine particles transported to the bigger distance. Mostly you can see
increased plutonium deposition at a higher distance and here internal is moreor less the same.
37

Male ParticipantOkay, thank you. So it might be 10 on the forest fire type and [Unclear] 5
itself type of [Unclear] I mean which are intensively higher or something likethat.
Dr. Vasyl Yoschenko
Yes. We performed our experiment on surface fire. Also we may think about
the fire of big intensities we will have countermeasures – so but we havecountermeasures for this case. And [Unclear] it’s a very worse scenario. Of
all the forest in the exclusion zone [Unclear] with – in intense fire with theinitial [Unclear] higher and, of course, the activity will be [Unclear]. In thiscase if you have the higher [Unclear] we have redistribution with distance
while plume particles travel [Unclear] so it is from the concentrations of in theeast due to this factor. We found [Unclear] that for this case then there will
not be any important transfer of radionuclides outside the exclusion zone.
The only problems can be related I skipped the conclusion part of [Unclear], in
generally the only problems can remain to the firefighters.
Male Participant
And I saw that most of the radiation dose is coming from the plutonium, so if
we think about the Japanese case it can be negligible with the forest value
curves?
Dr. Vasyl Yoschenko
Yes.
Male Participant
I understand. Thank you.
Female Participant
Thank you. My question is also forest fire related [ph]. How many days
does plume of fire remain in the air from the breakout of fire?
Dr. Vasyl Yoschenko
How long time the plume exists in air after the release?
38

Female ParticipantYes, yes. How many days plume in the air from the fire break?
Dr. Vasyl Yoschenko
We make our fire in forest you can see this is in this forest, which isapproximately 1 hectare area. It was burnt in say something like 2 hours.
The fire completed and the plumes burned to some say several hundred
meters. But of course, maybe there could be another stage of the fire which
is just small burning, which can last for some period after the fire.

Of course,

we could not leave this forest after the fire. The firefighters use quite somewaterproof [Unclear].

In general, it can be say several hours up to maybe

days but this is if there is a big fire.
Female Participant
I see. It remained only 3 hours or 4 hours only in the air and how long it
takes from Chernobyl to Kiev in the plume of – sorry?
Dr. Vasyl Yoschenko
I see. Well, first, the time depends on the [Unclear] okay, but I have toemphasize the plume particles and the particles released from [Unclear] aredifferent but smoke itself which can travel big distance as I’ve shown from
Chernobyl to Kiev like that. The release from the fire [Unclear] likely will
never get for such big difference. The impact of that area maybe kilometers
pretty much.
Female ParticipantOkay, thank you. Plume is not smoke and it’s very different…
Dr. Vasyl Yoschenko
Yeah.
Female ParticipantOkay, thank you.
Male Participant39

Is there any relationship between the concentration in materials that was
burnt in the concentration, the total amount in atmosphere?
Dr. Vasyl Yoschenko
If you look at this, this is the fraction which can be released during the –but
this is for our case for [Unclear] from forest fires. I would say that there is anintensive grass on fires but we also have very big productivity of grass at thesites here in turn [ph]. I believe it would be site specific but in general in thisorder of magnitude for the release.
[Japanese]
Male Participant
Thank you very much.
Dr. Vasyl Yoschenko
Thank you.
01:40:03 – 01:44:17[Multiple Speakers]
END

40