NORDIC RADIOECOLOGY
THE TRANSFER
OF
RADIONUCLIDES THROUGH
NORDIC ECOSYSTEMS TO MAN
This Page Intentionally Left Blank
Studies in Environmental Science
62
NORDIC
RADIOECOLOGY
THE TRANSFER
OF
RADIONUCLIDES
THROUGH NORDIC ECOSYSTEMS
TO MAN
Edited
by
H.
Dahlgaard
Ris~ National Laboratory
Roskilde, Denmark
ELSEVIER
Amsterdam
-
Lausanne
-
New
York
-
Oxford

Box
521,1000
AM Amsterdam, The Netherlands.
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V
PREFACE
The present book is the final milestone

energetic, persistent, diplomatic and occasionally maddening efforts of our travelling
"ambassador", Franz Marcus, executive secretary of the NKS from 1976
to
1994.
Henning Dahlgaard
Co-ordinator of the RAD programme
This Page Intentionally Left Blank
vii
CONTENTS
PREFACE
CONTRIBUTORS AND PARTICIPANTS
V
XI
Chapter
1
NORDIC RADIOECOLOGY
1990 -1993
1
1.1
The aims and justification of Nordic radioecology.
H.
Dahlgaard
3
1.2
General summary and conclusions.
H.
Dahlgaard,
M.
Notter,
J.

45

Vlll
2.4
Transport of 137Cs
in
large Finnish drainage basins.
R.
Saxtn
2.5
The role of lake-specific abiotic and biotic factors for the transfer of
radiocaesium fallout to fish.
T. Anderson and
M.
Meili
2.6
Models for predicting radiocaesium levels in lake water and fish.
U.
Bergstrom, B. Sundblad and
S.
Nordlinder
2.7
Radiocaesium
in
algae from Nordic coastal waters.
L.
Carlson and P. Snoeijs
2.8
Polonium-210 and radiocaesium
in

B.
Salbu
3.4
Contamination of annual crops.
M.
Strandberg
3.5
Transfer of 137Cs to cows’ milk
in
the Nordic countries.
H.S. Hansen and LAndersson
3.6
Radiocaesium transfer
to
grazing sheep
in
Nordic environments.
K.
Hove,
H.
Lijnsjo et al.
63
79
93
105
119
127
141
143
149

263
4.2
The transfer of radiocaesium from soil to plants and fungi
in
seminatural ecosystems. R.A. Olsen
265
4.3
Radiocaesium
in
game animals
in
the Nordic countries.
K.J.
Johanson
287
4.4
Pathways
of
fallout radiocaesium via reindeer to man.
E.
Gaare and
H.
Staaland
303
4.5
The distribution of radioactive caesium
in
boreal forest ecosystems.
R.
Bergman

Doses from the Chernobyl accident to the Nordic populations
via diet intake. A. Aarkrog
5.6
Internal radiation doses to the Nordic population based on
whole-body counting.
M.
Suomela and T. Rahola
DEFINITIONS, TERMS AND UNITS
INDEX
SPECIES INDEX
407
425
433
457
473
477
48
1
xi
CONTRIBUTORS
AND
PARTICIPANTS
Hannele
Aaltonen,
STUK, P.O.Box
14,
FIN
00881
Helsinki
Asker

Umel
Ulla
Bergstrom,
Studsvik Eco
&
Safety,
S
61182
Nykoping
Torolf
Bertelsen,
Statens Strllevern, Postboks
55,
N
1345
0sterh
Helge E.
Bjernstad,
Agricultural University of Norway,
N
1432
AS-NLH
Inggard
Blakar,
Agricultural University
of
Norway,
N
1432
AS-NLH

Kjeller
Olof
Eriksson,
Lantbruksuniversitetet, Box
703 1,
S
75007
Uppsala
Ake
Eriksson,
Lantbruksuniversitetet, Box
7031,
S
75007
Uppsala
Sverker
Evans,
Statens Naturvbdsverk,
Box
1302,
S
17125
Solna
Rolf
Falk,
Swedish Radiation Protection Institute, Box
60204,
S
10401
Stockholm

Institut for Radiofysik, Sahlgrenska Sjukhuset,
S
41345
Goteborg
Lars
EUkansson,
Uppsala Universitet, Viistra Agatan
24,
S
75220
Uppsala
Hanne
S.
Hansen,
Agricultural University of Norway,
N
1432
AS-NLH
Lars
Egil
Haugen,
Agricultural University of Norway,
N
1432
AS-NLH
Knut
Hove,
Agricultural University of Norway,
N
1432

Uppsala
Bernt
Jones,
Lantbruksuniversitetet, Box 7038,
S
75007
Uppsala
Pekka
Kansanen,
Helsingin kaupungin ymp., Helsinginkatv. 24, FIN
00530
Helsinki
Riitta
Korhonen,
VlT/YDI, Pb 208, FIN 02151 Espoo
Vappu
Kossila,
Lantbrukets forskningscentral, FIN
3
1600 Jokioinen
Andrew
Liken,
Agricultural University of Norway, N 1432 AS-NLH
Hans
Liinsjo,
Lantbruksuniversitetet, Box 7031,
S
75007
Uppsala
Sigurdur

Safety,
S
61 182 Nykoping
Tuire
Nygren,
Vilt- och
Fiskeriforskningsinstitutet,
Tutkimuslaitos, FIN 82950 Kuikkalampi
Elisabet D.
Olafsdijttir,
Geislavarnir rikisins, Laugavegur 118d,
Is
150
Reykjavik
Rolf
A.
Olsen,
Agricultural University of Norway, N 1432 AS-NLH
Deborah H.
Oughton,
Agricultural University of Norway, N 1432 AS-NLH
Olli
Paakkola,
Torpantie 1 B, FIN 01650 Vanda
Arja
Paasikallio,
Lantbrukets forskningscentral, FIN 3 1600 Jokioinen
Sigurdur
E.
Piilsson,

Chr.
Samuekson,
Institutionen f. Radiofysik, Lasarettet,
S
22185 Lund
Ritva
Saxbn,
STUK, P.O.Box 14, FIN 00881 Helsinki
Tone
Selnaes,
IFE, Postboks 40,
N
2007 Kjeller
Pauli
Snoeijs,
Uppsala Universitet, Box 559,
S
75122 Uppsala
Riitta
Sormunen-Christian,
Lantbrukets forskningscentral, FIN
3
1600 Jokioinen
Hans
Staaland,
Agricultural University of Norway, N 1432 AS-NLH
Eiliv
Steinnes,
Universitetet, AVH, N
7055

Tillander,
Helsinki Universitet, Radiokemiska inst., FIN
00014
Helsinki
Ole
Ugedal,
Finmark Distrikth0yskole, Follumsvei, N
9500
Alta
Finn
Ugletveit,
Statens Strilevern, Postboks
55,
N
1345
0sterh
Trygvi
Vestergaard,
Academia Faeroensis, Noatun, FR
100
Torshavn
Ingemar
Vintersved,
Forsvarets Forskningsanstalt,
S
17290
Sundbyberg
PROJECT LEADERS
Elis
Holm,

49,
DK
4000
Roskilde
Henning
Dahlgaard,
Riss National Laboratory, Postboks
49,
DK
4000
Roskilde (Co-ordinator)
Sigurdur
Magnusson,
Geislavarnir rikisins, Laugavegur 118d.
Is
150
Reykjavik
Franz
Marcus,
NKS, Postboks
49,
DK
4000
Roskilde
Judith
Melin,
SSI,
Box
60204,
S

Dahlgaard,
Rise National Laboratory, Postboks
49,
DK
4000
Roskilde
This Page Intentionally Left Blank
Chapter
1
NORDIC
RADIOECOLOGY
1990
-
1993
This Page Intentionally Left Blank
3
1.1.
THE AIMS
AND
JUSTIFICATION
OF
NORDIC RADIOECOLOGY
HEN"G
DAHLGAARD
Risar National Laboratory, DK-4000 Roskilde, Denmark.
SUMMARY
A description is given of the goals and background of the RAD programme described
in
this book.
The overall scientific aim of the Nordic Radioecology programme was

%k,
'37Cs
and
239Pu
-
found
in
the environment, required the elaborate analytical procedures and advanced electronic equipment
that were gradually developed during the 1960's
-
the "Golden Age" of radioecology. At most
institutions radioecology became a branch of
health
physics ultimately aiming at studying and
reducing the radiation dose to man. Attempts were made at several institutions to incorporate the
field
in
general ecology and to utilize the radionuclides as global-scale tracers for, e.g., studies of
atmospheric pollutant transport and trace element turnover. However interest
in
radioecology
dwindled with the declining activity from atmospheric fallout, and by the mid-1980's work
in
radioecology had been reduced to a minimum,
or
was even non-existent
in
several countries.
Furthermore the integrity of radioecologists and health physicists had been challenged by
"environmentalist" groups fighting the peaceful utilization of nuclear energy

different countries. The Nordic radioecology programme RAD, which is the subject of the present
book, was run under the auspices
of
the new NKS from 1990 to 1993. Via the NKS, the RAD
programme has had funding of around 6 million Danish kroner
(-
1 million
US
$).
As
the contents
of the present book will show, this is only a minor part of the total costs of the work described
here. However, without the catalytic support provided by the NKS much
of
the present work
would not have taken place, and efforts in different Nordic countries would not have been co-
ordinated.
Plans for the Nordic Radioecology programme 1990-1993 were described in the Scandinavian
languages
in
a publication issued by the Nordic Council of Ministers (NKS, 1989).
THE
NORDIC RADIOECOLOGY PROGRAMME
The RAD programme consists of four projects. As the largest doses to man immediately after the
Chernobyl accident were derived from the consumption of terrestrial products and freshwater fish,
the programme included 2 projects on terrestrial radioecology: RAD-3, Agricultural ecosystems
(project leader: Per Strand) and RAD-4, Forest and alpine ecosystems (project leader: Aino
Rantavaara), and
one
on

to the contamination of specially sensitive Nordic environments leading
to
a high transfer of
radiocaesium to man. It was considered important for the authorities to have access to up-to-date
knowledge of the spreading and turnover
of
radionuclides in different Nordic ecological systems
in
order
to
be able to decide on the relevant countermeasures. Furthermore, knowledge of the
contamination levels of agricultural products was necessary to assure exports and avoid
unnecessary
loss
of
resources.
There is an immense variation within the Nordic countries not only in the distribution of the
Chernobyl deposition, but also
in
the transfer of radiocaesium to man. The contamination of a
highly productive agricultural area is expected to give relatively small individual doses to a large
population during a short period, whereas the contamination of the lichen carpets utilized
as
winter-
grazing for reindeer,
or
of the abundant oligotrophic lakes, will give a larger individual dose to
a small population for many years.
The overall scientific aim of the Nordic Radioecology programme was
to

benefits
in
respect
of
preparedness for nuclear
accidents. On first thoughts this goal may seem remote from a scientific field programme on the
cycling
of
caesium
in
the environment. However, one benefit
of
keeping radioecological centres
alive is that the necessary measuring equipment is ready for use, and that competent staff are
available
to
take suitable samples and carry out reliable radionuclide analyses
the
very day an
accident happens.
In
addition, knowledge of the pathways of radionuclides through ecosystems to
man will be available.
A
nuclear preparedness plan without working scientific projects is like an
airforce without trained fighter pilots.
Maybe
the
most
important justification

of the NKA project
AKTU-200.
IFE,
P.O.
Box
40,
N
-
2007
Kjeller,
1990. 261
pp.
7
1.2.
GENERAL
SUMMARY
AND
CONCLUSIONS
HENNING DAHLGAARD', MANUELA NOTTER',
JOHN
E. BRITTAIN3, PER
STRAND4,
AINO RANTAVAARA'
AND
ELIS HOLM6
'Riss National Laboratory, DK
-
4000 Roskilde, Denmark.
2Swedish Environmental Protection Agency,
S

already reached the Nordic countries
on
Sunday, 27th April, and contamination was to continue
during May. Figure 1.2.1 shows the resulting ground deposition of 137Cs
in
kBq
m-2
in
the Nordic
countries Denmark, Finland, Norway and Sweden. Off
the
map, the Chernobyl contamination
on
Iceland and Greenland was very low, whereas the deposition
on
the Faroe Islands was 0.6-4.5
kBq
137~~
m-2
The Nordic post-Chernobyl radioecology programme, RAD, consisted
of
four projects. The
main radionuclides chosen for study were the two radiocaesium nuclides, 137Cs and 134Cs, because
they appeared to be the most important contributors to doses to man after the Chernobyl accident,
and because they are relatively simple
to
measure. However, a few results for %rand 210Po were
also reported. The present chapter is intended to give an overview
of
the results from the RAD

given
in
chapter
5
and
in
Holm (editor).
RAD-2:
Aquatic ecosystems (project leader: Manuela Notter) mainly concerned Nordic lakes,
as the major problems
in
aquatic environments after the Chernobyl accident appeared
in
fresh-
water systems. However, two minor projects were run
in
the marine environment. The results from
RAD-2
are described in detail
in
chapter
2.
RAD-3:
Agricultural ecosystems (project leader: Per Strand) focused on various aspects of
Nordic agriculture
in
relation to nuclear contamination: annual crops, cows’ milk, grazing sheep
and on countermeasures.
RAD-3
also included a study of physico-chemical forms and

in
the Nordic countries where ionic concentrations
in
freshwaters are
generally low. Chapter
2
identifies the important parameters determining radionuclide
concentrations in fish, thereby permitting the development and assessment
of
potential remedial
measures. Since the Chernobyl accident in 1986, there has been an intensive research effort
in
the
Nordic countries aimed at obtaining reliable input data for prediction models and determining the
important driving forces and parameters for such models.
Lakes received radionuclides from Chernobyl fallout via
two
sources: direct fallout on the
lake surface and leakage from
the
catchment. Chapter
2.2
describes fractionation techniques used
in
a study of the input of radiocaesium to three widely different Nordic lakes, Hillesjon
in
Sweden,
!&re Heimdalsvatn
in
Norway and Saarisjawi

in
all lakes almost all such plant material is retained
in
the lake. The
Nordic lakes studied differed
in
the concentration of 137Cs in the various molecular weight fractions
in
the water phase. Free ions may easily cross biological membranes and the low molecular weight
fraction is assumed to have a high degree of bioavailability. However, both organic and inorganic
substances in the water phase may affect the biological uptake of a given element.
In
fact, the low
molecular weight fraction showed
no
retention
in
the three study lakes and was exported
downstream. In contrast, half the colloidal (pseudocolloidal) fraction was retained during passage
through both &re Heimdalsvatn and Saarisjarvi.
In
Hillesjon, ten times more 137Cs flowed out
than flowed
in,
due to resuspension of 137Cs-ri~h sediments.
Although some of the radiocaesium
from
Chernobyl has been transported out of lakes
because
of

shallow lakes. Although this may transport 137Cs to deeper areas
where
it
is less available, it also increases its availability to the biota, delaying recovery
in
shallow
lakes.
The importance of leakage from catchment areas has been studied on a large scale
in
Finland,
where the whole country has been divided into seven different catchments, each with its own
characteristics with regard to fallout, soil type and topography (chapter
2.4).
However, during the
first year after the fallout the activity concentrations
in
lake waters and fish could be estimated
using simple relationships to the deposition.
In
subsequent years catchment characteristics played
an increasing role, leading to differences between lakes
in
the different catchment areas. For
example, a high incidence of bogs prolonged the decrease
of
137Cs in lake waters and
in
fish,
whereas a predominance of clay soils reduced the transfer
to