Introduction to Field Studies Deborah Oughton, CERAD

Transcription

1 Introduction to Field Studies Deborah Oughton, CERAD

2 Deborah Oughton: MINA410 Field studies intro, 2013 Overview What types of sites are available? What types of studies can be carried out? Challenges (as an introduction to specific cases and discussions)

3 Deborah Oughton: MINA410 Field studies intro, 2013 Types of Field Sites Accidents (Mayak, Chernobyl, Fukushima) Deliberate releases (Sellafield, Techa River, ) TENORM (technically enhanced naturally occuring radionuclides) High background sites (Space, nuclear reactors/reprocessing, ) 3

4 Deborah Oughton: MINA410 Field studies intro, 2013 The Sellafield fingerprint

5 Deborah Oughton: MINA410 Field studies intro, 2013 Nuclear sources

6 Case 2: Mayak Plutonium production site, Russia 6

7 Deborah Oughton: MINA410 Field studies intro, 2013 Lake Karachay, Mayak 7

8 Deborah Oughton: MINA410 Field studies intro, 2013 Explosion in waste tank, Mayak PA, 1957 First recorded case of ecosysyem damage tree deaths, soil invertebrate reduction after a radiological accident

9 Case3 : Fukushima, distribution of releases between land and sea Slide courtesy of Ken Buessler, 80% Fukushima contamination in ocean There are still some uncertainties on where and how much of different radionuclides were released to the environment. 1 Atmospheric deposition Mid-March (5 30 P Bq) P (peta) = Through river runoff small and continues 4 Through underground water flow small and continues? 2 Direct discharge After late-march (3 15 P Bq) small source today

10 One year history of cesium-137 in ocean immediately off Fukushima At nuclear power plant Ocean Cs levels peak on April 6th - possible reproductive effects and mortality for marine biota - Fukushima NPP represents unprecedented release of radionuclides to the ocean Levels of concern for seafood - levels decreased rapidly, then leveled off one banana Levels prior to March 11 US drinking water limit Highest ocean levels post Chernobyl - so there is a continued source -The majority of seafood below permissible levels for consumption Data from TEPCO April 1 June 1 Aug 1 Oct 1 Dec 1 Feb Slide courtesy of Ken Buessler, Persistently high levels in some marine organisms

11 What types of fish are most contaminated? - bottom fish & freshwater fish - still high after 1 year - variability unpredictable - 18% of fish reported are above limit Data source- Japan Fisheries Buesseler, Science, 2013 Ken Buesseler WHOI

12 Deborah Oughton: MINA410 Field studies intro, 2013 Komi site, Vodny Republic Between 1931 and 1956 the Vodny area in the Komi Republic, Russia, was the main site of Soviet radium production. Wastes from the industry caused contamination of the environment, leading to high levels of radionuclides, heavy metals and rare-earth elements in the surroundings. It is well established that ionizing radiation and heavy metals can cause damage to plants and animals; little is known about chronic effects on biodiversity at an ecosystem level (i.e., impacts at a population and community level). Transportation of radium concentrate in wooden barrels, 1940 (Evseeva et al 2000)

13 Deborah Oughton: MINA410 Field studies intro, 2013 Vodny 13

14 Field Study: Contaminated site and Reference site Species diversity: macrofauna taxonomic identification (30 plots per site) plants (Russian partners 15 Emmanuel Lapied

15 Site Assessment and Biomarkers (contaminated site and reference site) Soil characteristics (chemistry, geological, etc..) Radionuclide and metal analysis of soil, plants and organisms Dosimetry (external and internal). Collaboration on voxel worm with K Higely 16 Range of possible earthworm biomarkers: DNA damage (COMET), Apoptosis (TUNEL, Apopstain); qpcr, bystander,

16 L rubellus - genome sequenced Could be relevant for human studies Widely used in ecotoxicology and ecology 17

17 Molecular Biomarkers - ongoing Metabarcoding of soil DNA - community diversity (mitochondrial markers) Species and strain - earthworm barcoding (COII) Earthworm epigenetics (DNA methylation) - L rubellus ca. 25 per site + other common species 18

18 Field back to Laboratory. Adaptation Microorganism (standard metal adaptation tests, developed for radiation exposure); Earthworms transgenerational and planned resistance studies carried out by Russian colleagues (Velegzhaninov, I. et al. Barcelona) 19 Ilya Velegzhaninov

19 Deborah Oughton: MINA410 Field studies intro, 2013 Pilot study: invertebrate density (Lapied, unpublished) 20 Mean External µgy/hr: Clayey 17, Sandy soil 14; control Internal doses x greater

20 Deborah Oughton: MINA410 Field studies intro, 2013 Correlations between cause and effects challenging in environmental science

21 Deborah Oughton: MINA410 Field studies intro, 2013 What is Harm? (Slide courtesy of Tom Hinton) Wildlife defies Chernobyl radiation By Stephen Mulvey BBC News «It contains some of the most contaminated land in the world, yet it has become a haven for wildlife - a nature reserve in all but name.» 20 April 2006 Chernobyl 'not a wildlife haven' By Mark Kinver Science and nature reporter BBC News «The idea that the exclusion zone around the Chernobyl nuclear power plant has created a wildlife haven is not scientifically justified, a study says.» 14 August 2007

22 Deborah Oughton: MINA410 Field studies intro, 2013 Chernobyl: Significant Ecosystem Changes Replacement of pine (Red Forest) with Birch Demographic and agricultural changes

23 Fulushima Evacuation Area about 30km From F1 1.5μSv/h Slide from: Wataru Naito Research Institute of Science for Safety and Sustainability (RISS) Photo by Tetsuo Yasutaka

24 Dose level was reduced, but what extent? Photo by Tetsuo Yasutaka

25 Decontamination is going on.. In-Situ or Temporary Storage Interim Storage Final Disposal Site Photo by Tetsuo Yasutaka

26 Deborah Oughton: MINA410 Field studies intro, 2013 Field Study Uncertainties Influence of confounding factors such as other contaminants, weather, food or nutrient availability? Reliability of dose rate measurements/estimates in laboratory and field condition Spatial variability (e.g. in dose and dose rate due to contamination) and species mobility in the field Extrapolation from laboratory tests to field situations Relationship of biomarkers/endpoints to long term population effects? The shape of dose response curves, particularly at low dose and dose rates? Hormesis, non targeted mechanisms such as bystander effects and genomic stability? Field Ecology Uncertainties Workshop, Lancaster,

27 Case 4: Example of Dose Assessment: Central Asian Mining sites Stalin s Uranium mining Bjørn 30Olav Rosseland: Reiser i 2008 med miljøgifter og fiskevelfer Oughton et al., JER, 2013 Photo. B.O. Rosseland

28 Deborah Oughton: MINA410 Environmental Radiobiology, 2015 Uranium mining and tailing in former Soviet Union 31

29 Fieldwork in Kazakhstan in June 2006 E Kazachstan Kirgisistan 32 Uzbekistan Tadjikistan China

30 Deborah Oughton: MINA410 Environmental Radiobiology, 2015 ICRP Terrestrial RAPs

31 Deborah Oughton: MINA410 Environmental Radiobiology, 2015 Digmai Site, Tajikistan 1 m 10 cm - 10 cm 9,7 µgy/h 11,2 µgy/h 11,9 µgy/h - 1 m 13,6 µgy/h 34 Modelled external doses in good agreement (factor 2) of site measurements

32 µgy/hy NORWEGIAN UNIVERSITY OF LIFE SCIENCES Deborah Oughton: MINA410 Environmental Radiobiology, 2015 Estimated total doses (µgy/hr) to reference terrestrial organisms Kurday (mean Ra-226 U-238 Th-234 Pb-210 Ra-228 Th-228 U Oughton et al., 2013 Internal doses: 73-95% of total Ra-226 dominated at all sites

33 Deborah Oughton: MINA410 Environmental Radiobiology, 2015 Dose Conversion Co-efficient (DCC) and Daughter radionuclide DCC Daughter nuclides are included in the dose conversion coefficients of their parents, if their half-lives are shorter than 10 days (assuming that the daughters are in equilibrium with parents). Pb-210 (Bi-210) Ra-226 (At-218, Po-218, Bi-214, Pb-214, Rn-222, Po-214) Ra-228 (Ac-228) Th-228 ( Po-216, Tl-208, Bi-212, Pb-212, Rn-220, Po-212, Ra-224) Th-234 (Pa-234m, Pa-234) U-235 (Th-231) 36

34 Sampling of vegetation Bjørn 37Olav Rosseland: Reiser i 2008 med miljøgifter og fiskevelfer Photo: B.O. Rosseland

35 Deborah Oughton: MINA410 Environmental Radiobiology, 2015 Good agreement between ERICA Ra-226 and U Concentration Ratios in ERICA tool and site plants Total dose (ugy/hr) Reference grasses Site vegetation Kurday U Ra

36 Deborah Oughton: MINA410 Environmental Radiobiology, 2015 Doses to Biota: Kadji-Sai U mining site, Kyrgystan (µgy/hr) ERICA Assessment Tool Internal dose to worm Dose to gut 2-4 orders of magnitude greater Default ERICA database CR One data point U No data Ra Soil Activity concentrations CR worm U238/ Bq/kg 8.8 * 10-3 Ra Bq/kg 9.0 * 10-2 Oughton et al, JER, 2013

37 Deborah Oughton: MINA410 Environmental Radiobiology, 2015 Metal soil concentrations (mg/kg) Metal Kurday Issyk-Kul Digmai (n=2) LEL* (mg/kg) Cu Cr nd Ni Identified 20 a 54 potential 16 for 34multiple 10 stressor issues 100 As Mo n/a n/a Cd n/a *Environmental Quality Standards based on Lowest Effect Levels (LEL) (RIVM, 2001; EPA, 2004).

38 Deborah Oughton: MINA410 Environmental Radiobiology, 2015 Doses to aquatic organisms 41

39 Dead lake: Kurday Kazakstan Bjørn 42Olav Rosseland: Reiser i 2008 med miljøgifter og fiskevelfer Photo. B.O. Rosseland

40 Deborah Oughton: MINA410 Environmental Radiobiology, 2015 Estimated doses (µgy/hr) to reference aquatic organisms at Issyk-Kul Lake, Kyrgystan Po-210 internal doses dominated for most organisms U isotopes dominated for plants 44

41 Deborah Oughton: MINA410 Environmental Radiobiology, 2015 Metal Water concentrations (ug/l) Metal Kurday* Issyk- Kul Taboshar Dutch target Dutch intervention Cu (7.8) <2 na Mn 5 80 (2000) Cr (1.45) Ni (101) As (23) Mo (134) na * Concentration in a sample collected from the Artesian well is given in brackets.

42 Deborah Oughton: MINA410 Field studies intro, 2013 Field Study Uncertainties Influence of confounding factors such as other contaminants, weather, food or nutrient availability? Reliability of dose rate measurements/estimates in laboratory and field condition Spatial variability (e.g. in dose and dose rate due to contamination) and species mobility in the field Extrapolation from laboratory tests to field situations Relationship of biomarkers/endpoints to long term population effects? The shape of dose response curves, particularly at low dose and dose rates? Hormesis, non targeted mechanisms such as bystander effects and genomic stability? Field Ecology Uncertainties Workshop, Lancaster,

43 Deborah Oughton: MINA410 Field studies intro, 2013 Group Discussion Read the Fukushima butterfies paper Discuss the paper and possible problems and confounding factors with the paper s conclusions Is there a field study you would like to carry out related to Fukushima ecology?