radioecological studies in nordic countries after the chernobyl accident

Radioecological Studies in Nordic Countries after the Chernobyl AccidentSven P. NielsenRadiation Research Division

22/03/2011SFREK, Stockholm2 Risø DTU, Technical University of Denmark

Chernobyl Accident, Saturday 26 April 1986• Radioactive fallout in Denmark first

recognised at Risø on the morning of Monday 28 April from gamma spectrometric analysis of routine grass sample showing fresh fission products

• Contact to colleagues confirmed similar findings in Sweden

• Meteorological data indicated origin east of Scandinavia

• Countrywide monitoring initiated in Denmark to obtain overview, inform authorities and public

• Arrival on 27 April of airborne radioactivity at Risø detected by outdoor ionization chamber logging readings over weekend (TMI inspired project with Japanese colleague)

Ionization Chamber outdoor at Risø


Chernobyl Fallout in Denmark

131I in air (mBq m-3) Fallout by September 1986


Tjernobyl Fallout in Europe, 137Cs


Radioactivity in air (Risø, Haderslev og Allinge)

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1955 1965 1975 1985 1995 2005

Konc

entr

ation

(µBq

/m3 )

År

Sr-90

Cs-137

Be-7

Pb-210

Cs-137(H)

Pb-210(H)

Cs-137(A)

Pb-210(A)


90Sr and 137Cs in milk

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 201010

100

1000

10000

Bq Sr-90 (kg Ca)-1Bq Cs-137 (kg K)-1

Year

Nor

mal

ised

con

cent

ratio

n


Cesium-137 in cereals

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20100.01

0.1

1

10

100

BygHavreRugHvede

Year

Conc

entr

atiio

n (B

q/kg

)


Cesium-137 in Danish food and Danes

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 201010

100

1000

10000

Kost Urin Mennesker

Year

Nor

mal

ised

con

cent

ratio

n (B

q/kg

K)


Chernobyl Fallout in Nordic Countries

• Total direct input of Cs-137 to the Baltic Sea estimated at 4.7 PBq

• Activity ratio of Sr-90/Cs-137 in fallout about 2%


10° E 13° E12° E11° E

56° N

55° N

Kattegat-413

Langeland bælt

Femern bæltGedser odde

Øresund, N, A

Øresund, N, BHesselø Kullen

Kattegat SW

Asnæs rev

Halskov revØresund, S

Møen

Biannual seawater sampling


90Sr in seawater around Zealand


137Cs in seawater around Zealand


Radioactive isotopes vs. salinity in Danish waters 2007


Time series of 90Sr and 137Cs in Danish waters vs. salinity

90Sr

137Cs

5 10 15 20 25 30 35 40

S alin ity in ‰

0

25

50

75

100

125

150

137 C

s B

q m

-31 9 7 2

5 10 15 20 25 30 35 40

S alin ity in ‰

0

15

30

45

60

90S

r Bq

m-3

1 9 6 1


Transuranics in Danish Waters November 2003

0

1

2

3

4

5 10 15 20 25 30 35

Salinity (‰)

Con

cent

ratio

n (m

Bq/

m³)

Pu-239Pu-240Np-237

Plutonium and neptunium in Danish waters vs. salinity


I-129 in Danish Waters

0

0.1

0.2

0.3

0.4

5 15 25 35

Salinity (‰)

Conc

entra

tion

(Bq/

m³)

Nov-99

Jun-00

Dec-00

129I in Danish waters vs. salinity


Cesium-137 in cod

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 20100.01

0.1

1

10

100

FærøerneGrønlandNordsøenKattegatØstersøen

Year

Conc

entr

atio

n (B

q/kg

fw

)


EC Marina Balt Project 1996-1998• EC Marina Balt Project on an assessment of the radiological

exposure of man from radioactivity in the Baltic Sea• Two previous EC Marina Projects

– North European Waters (Marina, 1990)– Mediterranean Sea (Marina-Med, 1994)

• Expansion of EU in 1995 (Finland, Sweden and Austria)• Marina Balt Project starts in 1996 with participants from countries

around the Baltic Sea: Sweden, Finland, Russia, Poland, Estonia, Latvia, Lithuania, Germany, Denmark


Assessment• Compartment model

used to predict radionuclide concentrations in seawater and biota

• Sources considered– Nuclear weapons

fallout– Chernobyl fallout– Discharges from

nuclear facilities


Cs-137 in Baltic seawater

• Observed data from MORS HELCOM data base and other sources

1

10

100

1000

1 10 100 1000

Observed concentration (Bq/m³)

Pred

icte

d co

ncen

tratio

n (B

q/m

³)


Doses to Critical Groups in the West Baltic

1.E-12

1.E-09

1.E-06

1.E-03

1950 1960 1970 1980 1990 2000

YEAR

Indi

vidu

al d

ose

rate

(Sv/

y)

ChernobylNuclear TestsReprocessingNPPResearchDumping


Doses to Critical Groups in the West Baltic from NPP

1.E-15

1.E-14

1.E-13

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1970 1975 1980 1985 1990 1995 2000

Year

Indi

vidu

al d

ose

rate

(Sv/

y) 1:Barsebäck2:Forsmark3:Greifswald4:Ignalina5:Leningrad6:Loviisa7:Olkiluoto8:Oskarshamn9:Ringhals

1

2

9

46

7

3

5

8


Maximum Doses to Critical Groups in the Baltic

Region Max. annual dose(mSv y-1)

Kattegat 0.04Belt Sea 0.09West Baltic 0.1East Baltic 0.05Bothnian Sea 0.2Bothnian Bay 0.06Gulf of Finland 0.2Gulf of Riga 0.04


Collective Dose by Source

1.E-03

1.E-01

1.E+01

1.E+03

ChernobylFallout

Nuclear TestFallout

ReprocessingPlants

Nuclear PowerPlants

ResearchReactors

WasteDumping

SOURCE CATEGORY

MA

NSI

EVER

T


Collective Dose by Country

1.E+00

1.E+01

1.E+02

1.E+03

Sweden

Finlan

d

Poland

Denmark

Russia

Latvi

a

German

y

Estonia

France

Lithu

ania

Netherl

ands Ita

ly

United

King

dom

Spain

Belgium

Portug

al

Greece

Irelan

d

COUNTRY

MA

NSI

EVER

T


Collective Dose by Exposure Pathway

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

Fish ExternalRadiation

Inhalation Molluscs Crustaceans

EXPOSURE PATHWAY

MA

NSI

EVER

T


Collective Dose by Radionuclide

1.E-12

1.E-09

1.E-06

1.E-03

1.E+00

1.E+03

NUCLIDE

MA

NSI

EVER

T


NKS-B PARDNOR Project 2007-2010• Objectives: To address the need for recent and site-specific

data to be used in the underlying ECOSYS radioecology model of the ARGOS and RODOS decision support systems

• Examples:• Typical diets in the Nordic countries. ’Default’ dietary

information supplied with models like ECOSYS is often used uncritically, despite of warnings that it reflects location-specific conditions.

• Import fractions of food products. In a Nordic emergency situation it is important to know if food consumed is produced in the Nordic countries or imported from other areas.

• Animal feeding regimes. These differ from country to country and could significantly affect doses.


Swedish ARGOS implementation


Consumption of wheat and rye

0

10

20

30

40

50

60

70

80

90

DK-adults S-adults FI-adults N-adults D-adults

Cons

umpt

ion

(kg/

y)

Spring wheat, flour

Winter wheat, flour

Rye, flour

Comment: practically all Norwegian and Finnish wheat is spring wheat, whereas a very large fraction of the Danish and German wheat is winter wheat.


Consumption of potatoes, leafy vegetables and root vegetables

0

10

20

30

40

50

60

70

80

90

100

DK-adults IS-adults S-adults FI-adults N-adults FA-adults D-adults

Cons

umpt

ion

(kg/

y)

Potatoes

Leafy vegetables

Root vegetables


Consumption of beef and milk

0

50

100

150

200

250

DK-adults IS-adults S-adults FI-adults N-adults FA-adults D-adults

Cons

umpt

ion

(kg/

y)

BeefMilk


Consumption of beer and milk

0

50

100

150

200

250

DK IS S FI N D

Cons

umpt

ion

(kg/

y)

Beer (adults)

Milk (young children)


Consumption of brown and other cheese in Norway

0

1

2

3

4

5

6

7

8

9

10

N-young N-teenagers N-adults N-seniors

Cons

umpt

ion

(kg/

y)

Brown cheese

Other cheese

Brown cheese is made from goat’s milk whey, which is not included in ECOSYS. Transfer coefficients are needed.


Gender differences between Danish adults

0

20

40

60

80

100

120

Potatoes Leafyvegetables

Rootvegetables

Fruit Milk beef (cow) Beer

Cons

umpt

ion

(kg/

y)

f

m


Nordic foodstuffs not included in ECOSYS diet table

0

5

10

15

20

25

30

35

40

Reindeer Game Fish Wild berries Mushrooms

Consumption (kg/y)

N

FIDK

In Faroe Islands, whale meat and blubber (not considered in ECOSYS) constitute significant parts of the diet. Available Faroese data is old and uncertain.


Impact on dose of using site-specific dietary information

Comparison of total doses for different countries

0,00E+00

1,00E-02

2,00E-02

3,00E-02

4,00E-02

5,00E-02

6,00E-02

7,00E-02

8,00E-02

9,00E-02

11-04-1986 31-05-1986 20-07-1986 08-09-1986 28-10-1986 17-12-1986 05-02-1987 27-03-1987 16-05-1987

Date

Dos

e (m

Sv) Norway

DenmarkFinlandSwedenGermany


Percentage of foodstuffs produced within each country

Food N DK FI ISWheat 67 60 50 ~0Rye 40 86 15 ~0Potatoes 100 86 96 59Leafy vegetables

55¤ 75* 77# 33£

Berries 6 10¤ 69 ~0Milk 100 90 99 nButter 98 69 97 nCheese 93 63 66 nBeef 95¤ 88 86 nPork 95¤ 94 91 nLamb 95¤ 20 30 n

* Figure only valid for early June to mid-October; It is 0 the rest of the year.¤ Assumed values# Import of leafy vegetables is in Finland low in mid-June to September. £ For Iceland, only the fraction for total vegetables has been identified.


Animal specific feeding rations

Differences between German and Danish data

Southern Germany Denmark Lactating cattle Hay until 10th May, grass until 9th Nov., hay

until 31st Dec. Maize silage (70 %), grass silage (30 %) all year.

Beef cattle 96 % maize silage, 2 % winter barley, 2 % winter wheat all year

Grass silage until 15th May, grass until 15th Oct, grass silage until 31st Dec.

Goats/sheep Hay until 10th May, grass until 9th Nov., hay until 31st Dec.

Hay/straw until 15th May, grass until 15th Sept., hay/straw until 31st Dec.

Pigs 50 % winter barley, 50 % winter wheat all year

90 % winter barley, 10 % soy flour all year.

Chickens/hens Winter wheat all year Winter wheat all year

Product Bq/kg after 6 months (D) Bq/kg after 6 months (DK) Cream 1.8 100 5.4 10-3

Butter 5.2 10-1 1.5 10-3

Beef (cow) 8.6 100 2.3 10-2

Example of ECOSYS run (137Cs dry deposition on 1st May)


PARDNOR Conclusions• Data on Nordic diets has been compiled for application in foodchain

dose models different age groups: children (1-4 y); teenagers (<15 y); adults (ca. 30 y); senior adults (ca. 60 y)

• Considerable differences are found between Nordic diets, which can mean significant differences in dose for the same accident situation in different countries

• Very different fractions of important dietary components are produced locally in the different Nordic countries

• Differences in animal feeding regimes have been demonstrated to be important, depending on season

• Significant differences in crop development by season between Nordic countries

• Room for model improvement on important aspects (deposition on crops, soil and snow, weathering, leaching, fixation, soil types, transfer to milk and meat)

radioecological studies in nordic countries after the chernobyl accident

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