EFFEKTER OG MILJØRISIKO KNYTTET TIL INNGREP I OMRÅDER MED SULFIDRIKE MINERALER - Risikovurderinger og anbefalinger ved bygging i alunskifer

Transkript

1

2

3 EFFEKTER OG MILJØRISIKO KNYTTET TIL INNGREP I OMRÅDER MED SULFIDRIKE MINERALER - Risikovurderinger og anbefalinger ved bygging i alunskifer Lindis Skipperud Center for Environmental Radioactivity (CERAD CoE), Department for Environmental Sciences (IMV), Norwegian University of Life Sciences (NMBU) NMBU/CERAD 3

4 Risikovurderinger ERICA tool radiologiske effekter på organismer EQS environmental quality standards Vurderinger av innholdet av giftige metaller Cummaltive risk estimation Mulige effekter på organismer av kjemisk giftighet av elementer Benyttet faktiske tall fra 2015 feltarbeid

5 Risk assessment of field data ERICA ERICA Assessment Tool (tier 2), version 1.2.1, was used to estimate the radiological effects on the organisms in the aquatic environment at three stations. Measured activity of 238 U, 232 Th and 210 Po in water, sediments and organisms was used to estimate the effect (screening value 10 µgy/h). ERICA assessment tool provides an estimate of the expected dose rate and an estimate of conservative dose rate for selected organisms.

6 Comparing Environmental Quality Standards (EQS) for sediments Element Vigga v/ Jarenvannet (St.6) (mg/kg) Nordtangen (St. 7) (mg/kg) Horgenbekk en (St. 9) (mg/kg) LEL (range) a (mg/kg) PEC b (mg/kg) Cu Ni As 1,9 6, Mo 1,3 5, Cd 0,28 0,55 0,81 0,91 2,4 2, Pb 3, a EQS based on Screening Values, Lowest effect levels (LEL) and ECO-SSL (RIVM, 2001; EPA, 2004;MacDonald et al., 2000). b Predicted Effect Concentrations (PEC) reflecting concensus levels for ecological effects for one ore more groups of organisms (EPA, 2000). Consentrations of Ni can be compared to the generic 10 µgy/h for ionising radiation, so we have a case of possible multiple stressor scenario.

7 Cummulative risk estimation of U and metals Model to identify the organisms at risk Predicted risk: Algea Fish Bentic Elements giving possible risk of toxisity: U 90% for algea Ni 46% for bentic Al 95% for fish Total risk: 1 predicting risk 10 predicitng high risk

8 Leaching experiments of different alum shale minerals Uranium 0.45 µm Ox: A 0.45 µm Ox: B 0.45 µm Ox: C 0.45 µm Red: A 0.45 µm Red: B 0.45 µm Red: C 0.45 µm Redox conditions does not have that much effect on U leaching ph have huge effects on U leaching

9 Fish exposure experiments Uptake studies in fish Salomo trutta Studied uptake from leachate water from 3 different minerals with different ph 0.45 µm filtration of leached water Brown trout Controlled ph, temperature Dark, no unnecessary disturbances Uptake experiment: One concentration, sampling fish at 6, 12, 24, 96 and 264 h Dose-response experiment: Several concentrations, sampling at 196 h

10 Uptake experiment cont. Mo, Cd and U present as low molecular mass species assumed bioavailable Experiment 1-96 hours (alum shale) Experiment 1-96 hours (E18) Experiment hours (alum shale) Vigga (Field data) ph 7.8 ± ± Temperature ( o C) 9.4 ± ± Ca (mg/l) 36.4 ± ± U (µg/l) 171 ± BCF U (L/kg gills) Mo (µg/l) 1326 ± 6 < BCF Mo (L/kg * gills) Cd (µg/l) 1.3 ± ± BCF Cd (L/kg gills) Po (Bq/L) BCF Po (L/Kg bein)

11 Cadmium on fish gills

12 Uranium on fish gills

13 Uranium in fish liver

14 Dose - response experiment fish RV4- Alum shale : Acute exposure experiment 96 hrs (OECD 1992) 6 different concentration -7 brown trouts in each The results indicated: Ca Cu Zn As Mo Cd U V Mn Ni mg/l µg/l µg/l µg/l µg/l µg/l µg/l µg/l µg/l µg/l Control A Control B A 2, A 8, A 17, A A that exposure to a mixture of metals leaked from alum shale in water with high ph and a relatively high Ca concentration did not contribute to negative mechanisms giving harmful effects on fish. Results from analyzes of gene expression reinforces the results of the physiological responses and the absence of adverse effects in fish. Important to remember: high Ca-concentration and high ph!

15 Dose response Daphnia magna Acute 48 hours and Cronic 21 days tests ph 7.5 T = 20 C Acute test with D. magna gave leathal effect as a function of concentration giving: NOEC = 3744 μg U/L, LOEC = 9359 μg U/L EC50 = 7124 μg U/L

16 Conclusions Leaching experiments The different leaching experiments showed that there is possibilities for leaching and the contamination of the aquatic environment, especially at lower ph Leaching can be a problem for a long time But at this specific site, the rock showed large buffer capacity (probably carbonates), remaining on high ph The chemical element of calcium and manganese dissolve easily and fast, but where most other metals, including uranium is more inert at this high ph. Remobilization potential is therefore considered to be low as long as the rock buffer capacity is intact.

17 Conclusions cont. Uptake and effect on organisms There is an effect on the benthic community in the area significantly affected by the construction work. No effects seen on fish in the field In the experiments, clear uptake of U and other elements (Mo and Cd) was shown for gills, kidney and liver. High ph and high Ca levels are protective of aquatic organisms such as fish, therefore despite metal deposition was detected in fish organs, any significant negative effects on the fish was not found confirmed by qpsr/gene expressions Lower ph and lower Ca content will give much higher uptake of U and increase probability of effects.

18 Conclusions cont. Risk estimates Radiological risk based on Erica Tool indicates that the radiological consequences are small, except in one site where level exceeds a dose rate of 10 μgy / h. Cumulative risks associated with metals (especially U, Al, Ni) varied widely between the various sites. All sites proved to represent a risk for the three groups of species (algae, crustaceans, fish) tested. Water from one of the sites proved to represent high predicted risk to algae and crustaceans, and lower risk to fish. High predicted risk appears to match the observation of a possible change in species composition the benthic community.

19 Anbefalinger De viktigste anbefalinger etter endt prosjektperiode vil være: Rensetiltak av avrenningsvann fra anlegg må stedstilpasses og optimaliseres etter stedets vannkvalitet. Bruk av sorbenter anbefales da sedimentering ikke tar lavmolekylære, mobile metaller fra vannet. Kommersielle sorbenter som DB-12P-HP kan anbefales ved høy ph (ph rundt 7, som på Gran) mens Olivin-Al kan anbefales ved lavere ph (ned til ph 4)

20 Anbefalinger Horgenbekken og bekken ved Nordtangen bør vurderes renses. Hvis mulig bør Horgenbekken gå i rør hele veien og rensing settes inn før avløp til Jarenvannet. Det bør gjennomføres etterundersøkelser knyttet til avrenning fra anlegget ca. 5 år etter at anleggsarbeidene er avsluttet. Etterundersøkelsene bør fokusere på sedimentkjerner i Jarenvannet da dette vil være en god indikator på avrenning fra de nærliggende områdene inkludert anleggsområdet. Bunndyrundersøkelser i elver og bekker som vil vise miljøstatus etter endt anleggsarbeid. Prøvetaking av fisk i Vigga og i begge basseng av Jarenvannet da det kan være forskjell i påvirkning av fisken i basseng sør ved utløp Vigga og i basseng nord. Dette kan gjerne gjøres allerede 1 år etter ferdigstilling av anlegget og så repeteres etter 5 år.

21 Takk til Funding: the Nordic Road Water Project (NORWAT) Hedda Vikan, Sondre Meland, Halldis Fjermestad, Malin Torp, Turid Hertel- Aas, Per Hagelia at Norwegian Road Construction Authority Frøydis Meen Wærsted, Hans-Christian Teien, Brit Salbu, Lene Sørlie Heier, Marit Nandrup Pettersen, Lene Valle at Center for Environmental Radioactivity (CERAD), Norwegian University of Life Science (NMBU), Knut Erik Tollefsen, Øyvind Aaberg Garmo, Tore Høgåsen, Maria Hultman, Tânia Gomes og Ailbhe Macken at The Norwegian Institute for Water Research (NIVA) 7 MSc students Tusen takk! Erlend Hjortland Sandøy

22 Presentasjoner av resultatene NRC9 Nuclear and Radiochemistry conference in Helsinki, Finland invited oral presentation NORM VIII Eight international symposium on Natural Occuring Radioactive Material in Rio de Janeiro, Brasil oral presentation & poster NETS - 6th Norwegian Environmental Toxicology Symposium in Oslo, Norge -??? II International conference on radioecological concentration processes in Sevilla, Spania oral presentation

23 Takk for meg!