The risk of crude oil exposure to the early life stages (ELS) of fish is difficult to assess, given the complexity of the chemical composition of different oils. The aromatic portion of crude oil contains polycyclic aromatic hydrocarbons (PAH), which are known to be toxic. In 2004, an “effects-driven” fractionation research program was initiated in an attempt to better identify toxic constituents of two unique crude oils, Alaskan North Slope Crude (ANSC; medium-heavy crude) and Scotia Light (SCOT; light crude). The ANSC contained much more PAH than SCOT. These oils induced cytochrome P4501A1 (CYP1A) enzymes in juvenile rainbow trout (Oncorhynchus mykiss) and caused blue-sac disease (BSD) and mortality in larval Japanese medaka (Oryzias latipes).
Four unique fractions (F1-F4) were produced from both oils via low temperature vacuum distillation. The F3 contained an array of unsubstituted and alkyl-PAH, and was responsible for most of the CYP1A induction and chronic toxicity associated with whole oil. Cold acetone extraction (CAE) of F3 produced 2 new sub-fractions (F3-1 and F3-2). The F3-1 was rich in alkyl-PAH, was a potent CYP1A inducer, and was chronically toxic to ELS of fish. The F3-1 was further separated into five more sub-fractions via normal phase HPLC (F3-1-1 – F3-1-5). Neither F3-1-1 nor F3-1-2 induced CYP1A or produced BSD, but F3-1-2 was lethal. The F3-1-3, 4, and 5 were all potent CYP1A inducers and were all chronically toxic.
Induction of CYP1A proved to be an effective tool for tracing potentially toxic PAH throughout fractionation (Chapter 2), and sub-fractions rich in alkyl-PAH caused the most BSD and mortality (Chapter 3). Alkyl-homologues of phenanthrene, fluorene, naphthobenzothiophene (NBT), pyrene, and chrysene are perhaps the most toxic of the known constituents present in crude oil. The ANSC sub-fractions were more toxic than the SCOT ones, indicating that heavier crude oils with a higher proportion of intermediate-sized alkyl-PAH may be more toxic than lighter crude oils that are comprised of fewer of these compounds. / Thesis (Master, Biology) -- Queen's University, 2007-12-20 13:18:50.794 / This research was accomplished with funding assistance from the Nationmal Oceanic and Atmospheric Administration (NOAA), Petroleum Research Atlantic Canada (PRAC), Environment Canada, and the Department of Fisheries and Oceans.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/956 |
| Date | 02 January 2008 |
| Creators | Khan, Colin Winston |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | 2828243 bytes, application/pdf |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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