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Oil Sands Processes Affected Water …

Oil Sands Processes Affected Water …. Steve Wiseman Toxicology Centre University of Saskatchewan. Problem: How To Deal with the Large Volumes of OSPW?. Surface mining industry produces large volumes of OSPW OSPW must be reclaimed as viable aquatic habitat 27 end-pit lakes planned

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Oil Sands Processes Affected Water …

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  1. Oil Sands Processes Affected Water … Steve Wiseman Toxicology Centre University of Saskatchewan

  2. Problem: How To Deal with the Large Volumes of OSPW? • Surface mining industry produces large volumes of OSPW • OSPW must be reclaimed as viable aquatic habitat • 27 end-pit lakes planned • First (Base mine lake) will be filled this year with OSPW from WIP (Syncrude) • EPLs will eventually flow into the natural system

  3. Can We Accelerate Detoxification of OSPW ? • Toxicity of 1st EPLs are predicted to persist until 2070 • Need to accelerate the detoxification process

  4. Ozonation Decreases NAs in OSPW? OSPW After Ozonation with 80 mg O3/L OSPW NAs Before Ozonation O3

  5. Attenuation of Embryotoxicity Survival a a a Survival Pericardial Edema Pericardial Edema b a a a c c b b b a b a b

  6. Attenuation of Developmental Toxicity

  7. No Effect on Estrogenicity of OSPW – in vitro • Ozonation neither attenuated nor potentiated estrogenicity of OSPW. • Chemical(s) in OSPW and ozonated OSPW bind to the ER. b b Estrogenic response a a a Rowland et al., 2011

  8. No Effect on Estrogenicity of OSPW – in vivo Egg Envelope Proteins- Males Egg Envelope Proteins - Females a b a b a b a a a a a a b b b b b b • Could explain the decreased fecundity in female minnows (Kavanagh et al., 2011) and less prominent male secondary sexual characteristics in male minnows.

  9. Problem: How do we monitor for exposure to and effects of OSPW? Need: Determine the Critical Mechanism(s) of Toxicity of Oil Sands Process Affected Water If we know critical mechanisms of action then we can design assays to monitor for exposure to OSPW

  10. Mechanism(s) of Toxicity of OSPW • Because NAs are surfactants, OSPW might have toxicity via narcosis. Control CL CS NA O3-OSPW AC-OSPW OSPW

  11. Transcriptomics • Given the complexity of OSPW there might be multiple mechanisms of toxicity. • Adverse outcome pathways • Processes that lead to toxicity are often initiated at the molecular level + Chemical Direct interaction with receptor Molecular event (ie. transcriptional response) Cellular processes • Quantify abundances of transcripts in the livers of male fathead minnows exposed • to OSPW might provide some insight into potential mechanisms of toxicity. Population level effect Organism level effect

  12. Results 1 : Global Gene Expression Functional annotation using GO terms and KEGG mapping to identify process indicative of effects of OSPW.

  13. Biotransformation OSPW-OC AhR CAR PXR Phase I CYP3 GST MDR ST CYP1A GST MDR UGT CYP2 Phase II Phase III Are organics in OSPW being metabolized? Effect on toxicity? Oxidative metabolism

  14. Oxidative Stress - I Glutathione metabolism Pentose-phosphate shunt Transcription factor GSH Synthase ROS NRF2 GSH H202 NADP Glutathione Peroxidase Glutathione Reductase G-6-PDH 6-PGDH Transketolase AO MOA AlDH EH GST UGT MDR H20 + 02 GSSG NADPH

  15. Oxidative Stress - II ROS Complex I Complex III Complex I and III are major sites of production of ROS http://en.wikipedia.org/wiki/File:Mitochondrial_electron_transport_chain%E2%80%94Etc4.svg

  16. Apoptosis AIF AIF AIF PARP Cathepsin b ROS

  17. Mechanism of Toxicity OSPW-OC CAR mitochondria AhR Complex I Complex III PXR Apoptosis nucleus GST UGT MDR nrf2 AO MOA AlDH EH GST UGT MDR CYP1A CYP2K CYP2AD CYP2N ROS OSPW-OC

  18. Development of Deformities Hemorrhage Pericardial edema Malformation of spine Effects are similar to those caused by dioxins and dioxin-like chemicals (PAHs).

  19. Biotransformation Enzymes b a a a • No change in transcript abundance of cyp1a • No activation of Aryl-hydrocarbon Receptor (AhR) signaling • No PAHs in OSPW. • Greater transcript abundance of cyp3a • Activation of Pregnane-X-Receptor (PXR) • Ozonation & activated charcoal treatment attenuated the effects

  20. Oxidative stress Reactive oxygen species Oxidative stress responsive genes b b a a b a b a a a a a a a a a • Greater conc. of ROS • Greater transcript abundance of gst& sod • Ozonation & activated charcoal treatment attenuated the effects

  21. Apoptosis b b b a a a a a a a a a • Caspase-activated apoptotic cell death induced by oxidative stress • Ozonation & activated charcoal treatment attenuated the effects

  22. Conclusion • The toxicity of OSPW due to dissolved organic compounds. • The mechanisms of the effects of the dissolved organic compounds are unknown. • The identities of the compounds that cause effects are unknown.

  23. OSPW Toxicity (250,000 chemicals?) Characterization of Biological Effects Development of Appropriate Bioassays Characterization of Chemical Content Effects Biomarkers Chemical and biological characterization of OSPW will lead to strategies to deal with OSPW

  24. Jon Martin Mohamed Gamal El-Din Nan Wang Leo Perez-Estrada John Giesy Yuhe He Julie Anderson RishiMandinky Markus Hecker Paul Jones Sarah Peterson Warren Zubot

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