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Thesis Outline UNDERSTANDING SOURCES OF PERFLUORINATED ACIDS TO BIOLOGICAL SYSTEMS by Craig Michael Butt A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Department of Chemistry University of Toronto © Copyright by Craig M. Butt, 2010 Understanding Sources of Perfluorinated Acids to Biological Systems Doctor of Philosophy Degree, 2010 Craig M. Butt Department of Chemistry, University of Toronto ABSTRACT The overall aim of this thesis was to investigate the fate of perfluorinated alkyl compounds (PFCs) in biological systems. During the past several years, it has been shown that wildlife are ubiquitously contaminated with two classes of PFCs, the perfluoroalkyl carboxylates (CxF2x+1C(O)OH, PFCAs) and sulfonates (CxF2x+1SO3H, PFSAs). However, there is still considerable uncertainty regarding how wildlife are accumulating these PFCs, particularly in remote areas such as the Canadian arctic. The potential for fluorotelomer acrylate monomers (CxF2x+1CH2CH2OC(O)CH=CH2, FTAcs) to act as precursors to PFCAs through atmospheric oxidation was investigated using smog chamber experiments. FTAc atmospheric fate is determined by OH radical reaction with a lifetime of approximately 1 day. The sole primary product of this reaction was the 4:2 fluorotelomer glyoxylate which is expected to undergo further atmospheric oxidation or photolysis to ultimately yield PFCAs. Temporal and spatial trends of PFCs in arctic ringed seals and seabirds were investigated to assist in understanding PFC transport mechanisms to remote regions. In ringed seals, perfluorooctane sulfonate (PFOS) levels decreased rapidly, coinciding with the phase out by the major manufacturer. These findings are consistent with volatile precursors as the dominant source of PFCs to arctic wildlife. The bioaccumulation and biotransformation of the 8:2 FTAc was investigated in two complimentary studies with rainbow trout. During the in vivo dietary exposure study, fish rapidly accumulated and biotransformed the 8:2 FTAc, with intermediate metabolites observed within 1 hour of dosing. Perfluorooctanoate (PFOA), perfluorononanoate (PFNA) and perfluoroheptanoate (PFHpA) were formed and accumulated in low yields. The carboxylesterase activity in the trout liver and stomach was investigated using in vivo sub- cellular (S9) incubations. Very high esterase activities were shown with approximately equal efficiency in the stomach and liver. ii The metabolic pathway of the 8:2 fluorotelomer alcohol (8:2 FTOH) was investigated by separately dosing whole rainbow trout with three intermediate metabolites that represented important branching points. The 7:3 fluorotelomer saturated carboxylate (FTCA) did not form PFOA, but formed PFHpA and the 7:3 fluorotelomer unsaturated carboxylate (FTUCA). The 8:2 FTCA and 8:2 FTUCA did form PFOA, confirming a “beta-like-oxidation” mechanism. iii ACKNOWLEDGEMENTS A few moments for the author to express his humility. I have had the fortune of being mentored by two inspiring supervisors, Scott Mabury and Derek Muir. They have served as excellent role models, each with their own strengths and bias, guiding me through my progression as a graduate student. The research opportunities have been unparalleled. Derek – I am grateful for your supportive nature, extremely quick turnaround on manuscripts and unequaled accessibility. Scott – thank you for pushing my development beyond an “X and Y” chemist, I will miss our late night and weekend chats. Thank you also to Frank Wania for serving as the chair of my PhD committee and to Jamie Donaldson for acting as the final committee member. I have also been able to collaborate with several excellent scientists during my tenure. Rosanna Bossi (University of Aarhus, Denmark), Urs Berger (Stockholm University, Sweden)) and Gregg Tomy (Department of Fisheries and Oceans) were co-authors for the arctic review paper. Tim Wallington and Mike Hurley at the Ford Motor Company provided project guidance, technical assistance and expertise during the 4:2 acrylate atmospheric study. Birgit Braune at the National Wildlife Research Centre (Environment Canada) was the project investigator for the temporal seabird study. Thank you to all past and present members of the Mabury group – Dave, Jon, Xinghua, Suzanne, Jules, Monica, Naomi, Uli, Joyce, Erin, Sarah, Anne, Pablo, Amy (my swim coach), Holly and Derek (“We know what we did”). Whether by luck, or by vision, I am grateful to have worked with an incredibly talented and inspiring group. In particular I have enjoyed our non-academic times together – if this group wasn’t so fun, I would have graduated years ago! I have learned something from each one of you, including those who have taught me the virtue of patience. My hope is that you also learned something from me. I have also been fortunate to mentor several undergraduate students throughout my tenure as a PhD student. Many thanks to Yan Li, Helen Sun, Clara Chan, Rodolfo Gomez, Alex Tevlin and Rob Di Lorenzo for assistance with sample preparation. iv Many thanks also to the team at Canadian Centre for Inland Waters (Environment Canada) under the supervisor of Derek Muir. Xiaowa Wang provided assistance in the management of the arctic biota samples. Christine Spencer ensured that the LC-MS/MS was in good working order and free from contamination. Jeff Small assisted with the operation of the LC-MS/MS and, along with Colin Darling, provided much appreciated friendship. I could not have completed this degree without the friendship of four truly amazing people, in no particular order – Amila De Silva, Jessica D’eon, Zamin Kanji and Cora Young. You’ve been wonderful companions on this crazy ride. Your contributions are beyond words. We’ve travelled together, competed together, laughed together, drank together and vented our frustrations together. Your (planned) interventions were appreciated. You opened your doors to me when I needed it the most. How is it that you know me better than I know myself? Of all the stories I tell, the most cherished are those that involve you. To all the individuals I have known outside of the academic “bubble”, you have helped me achieve balance in life. You have managed to keep me sane, and for some, coincidently driven me insane. Rock climbing, hockey, running, friendship and patio beers. Thank you for nodding your head, smiling and acting interested when I explained my research. In particular, thank you to Jeff Rands of VWR Canada – my stomach has greatly benefited from your expense account. To Sparky the Cat (aka – Sparkles MacPuss), I am thankful for your big meows and furry kisses. I am grateful to my family for their everlasting love and support throughout my many years as a graduate student. Thank you for your constant encouragement and allowing me to trust my instincts. After years of asking, “When will you be finished?” I can confidently and definitively answer, “Now”. v TABLE OF CONTENTS Chapter One – Introduction to Poly- and Perfluorinated Compounds 1 1.1. Overview 2 1.2. Perfluorooctane Sulfonyl Fluoride-Based Compounds 4 1.3. Fluorotelomer-Based Compounds 6 1.4. Sources of Poly- and Perfluorinated Acids to the Environment 8 1.4.1. Direct Sources 8 1.4.2. Indirect Sources 8 1.4.2.1 Atmospheric Reactions 8 1.4.2.2 Polyfluorinated Compound Biotransformation 11 1.4.2.2.1 Fluorotelomer-based Compounds 11 1.4.2.2.1.1. Microbial 11 1.4.2.2.1.2. Rats and Mice 15 1.4.2.2.1.3. Biotransformation of Fluorotelomer-based 20 Compounds: Summary and Conclusions 1.4.2.2.2. Polyfluorinated Sulfonamide Compounds 23 1.4.2.2.2.1. N-ethyl perfluorooctane sulfonamide (N- 23 EtFOSA) 1.4.2.2.2.2. N-ethyl perfluorooctane sulfonamide ethanol 24 (N-EtFOSE) 1.4.2.2.2.3. Biotransformation of Polyfluorinated 25 Sulfonamide Compounds: Summary and Conclusions 1.5. Bioaccumulation of organic compounds 27 1.5.1. Definitions 27 1.5.2.Contaminant Uptake and Elimination in Fish 28 1.5.3. Xenobiotic Metabolism in Fish 29 1.5.3.1. Extrahepatic Metabolism in Fish 30 1.5.4. Quantifying Metabolism in Fish 30 1.5.5. Quantifying Bioaccumulation 32 1.5.5.1. Laboratory-based Experiments 32 1.5.5.2. Models to Predict Bioaccumulation 32 1.5.5.2.1. Empirical Correlation Models 32 1.5.5.2.2. Mechanistic Models 33 1.5.5.2.2.1. Extrapolating In Vitro Metabolic Data to 36 Predict In Vivo Bioaccumulation 1.6. Literature Cited 38 Chapter Two – Levels and Trends of Poly- and Perfluorinated Compounds in 45 the Arctic Environment Butt, C.M.; Berger, U.; Bossi, R.; Tomy, G.T. Submitted to The Science of the Total Environment 2.1. Abstract 48 2.2. Introduction 50 2.3. Transport Pathways 51 2.4. Biotic Measurements 59 2.4.1. Trends 59 2.4.1.1. Food Web Studies 59 2.4.1.2 Spatial Studies 64 2.4.1.3 Temporal Trends 72 vi 2.4.1.3.1. North American Arctic 72 2.4.1.3.2. Greenland 80 2.4.1.3.3. Norway 84 2.4.2. PFC profiles 85 2.4.3. Animal Body Burdens 87 2.4.4. “Neutrals” and Precursors 88 2.5. Abiotic Measurements 90 2.5.1. Atmospheric Measurements 90 2.5.2. Snow 92 2.5.2.1. Canadian Arctic 92 2.5.2.2. Greenland 93 2.5.3. Lake Water & Sediments 93 2.5.3.1. Amituk, Char & Resolute lakes on Cornwallis Island, Canadian 93 Arctic 2.5.3.2. Isomers in Char Lake sediments; Surface Water from Char Lake 95 and Amituk Lake 2.5.4. Seawater and Marine Sediments 96 2.5.4.1. Greenland Sea 96 2.5.4.2. Labrador Sea 96 2.5.4.3. Canadian Arctic 97 2.5.4.4. Iceland & Faroe Islands 97 2.5.4.5. Russian Arctic 98 2.5.5. Sewage sludge & effluent 98 2.6.
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