Radioecological Studies in Nordic Countries after the Chernobyl Accident

1. Radioecological Studies in Nordic Countriesafter the ChernobylAccident Sven P. Nielsen Radiation Research Division

2. ChernobylAccident, Saturday 26 April 1986 • Radioactivefallout in Denmark firstrecognised at Risø on the morning of Monday 28 April from gamma spectrometricanalysis of routinegrass sample showingfresh fission products • Contact to colleaguesconfirmedsimilarfindings in Sweden • Meteorological data indicatedorigineast of Scandinavia • Countrywide monitoringinitiatedin Denmark to obtainoverview, informauthorities and public • Arrivalon 27 April of airborneradioactivity at Risø detected by outdoorionizationchamberloggingreadings over weekend (TMI inspiredprojectwithJapanesecolleague)

3. IonizationChamberoutdoor at Risø

4. ChernobylFallout in Denmark 131I in air (mBq m-3) Fallout by September 1986

5. Tjernobyl Fallout in Europe, 137Cs

6. Radioactivity in air (Risø, Haderslev og Allinge)

7. 90Sr and 137Cs in milk

8. Cesium-137 in cereals

9. Cesium-137 in Danish food and Danes

10. 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%

12. Biannual seawater sampling

13. 90Sr in seawater around Zealand

14. 137Cs in seawater around Zealand

15. Radioactive isotopes vs. salinity in Danish waters 2007

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

17. Plutonium and neptunium in Danish waters vs. salinity

18. 129I in Danish waters vs. salinity

19. Cesium-137 in cod

20. 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

21. Assessment • Compartment model used to predictradionuclideconcentrations in seawater and biota • Sourcesconsidered • Nuclearweaponsfallout • Chernobylfallout • Discharges from nuclearfacilities

22. Cs-137 in Baltic seawater • Observed data from MORS HELCOM data base and other sources

23. Doses to Critical Groups in the West Baltic

24. Doses to Critical Groups in the West Baltic from NPP

25. Maximum Doses to Critical Groups in the Baltic

26. Collective Dose by Source

27. Collective Dose by Country

28. Collective Dose by Exposure Pathway

29. Collective Dose by Radionuclide

30. NKS-B PARDNOR Project 2007-2010 • Objectives: To address the need for recent and site-specific data to beused in the underlying ECOSYS radioecology model of the ARGOS and RODOS decision support systems • Examples: • Typicaldiets in the Nordic countries. ’Default’ dietary information suppliedwith models like ECOSYS is oftenuseduncritically, despite of warningsthat it reflectslocation-specificconditions. • Import fractions of foodproducts. In a Nordic emergency situation it is important to knowiffoodconsumed is produced in the Nordic countriesorimported from otherareas. • Animal feeding regimes.Thesediffer from country to country and couldsignificantlyaffectdoses.

31. Swedish ARGOS implementation

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

33. Consumption of potatoes, leafy vegetables and root vegetables

34. Consumption of beef and milk

35. Consumption of beer and milk

36. Consumption of brown and other cheese in Norway Brown cheese is made from goat’s milk whey, which is not included in ECOSYS. Transfer coefficients are needed.

37. Gender differences between Danish adults

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

39. Impact on dose of using site-specific dietary information

40. Percentage of foodstuffs produced within each country * 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.

41. Example of ECOSYS run (137Csdry deposition on 1st May) Animal specific feeding rations Differences between German and Danish data

42. PARDNOR Conclusions • Data on Nordic diets has beencompiledfor application in foodchaindosemodels 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)