title: Comparison of Diluted Bitumen (Dilbit) and Conventional Crude Oil Toxicity to Developing Zebrafish.
abstract: To facilitate pipeline transport of bitumen, it is diluted with natural gas condensate, and the resulting mixture, "dilbit", differs greatly in chemical composition to conventional crude oil. Despite the risk of accidental dilbit release, the effects of dilbit on aquatic animals are largely unknown. In this study, we compared the toxicity of water accommodated fractions (WAFs) of dilbit and two conventional crude oils, medium sour composite and mixed sweet blend, to developing zebrafish. Mortality and pericardial edema was lowest in dilbit WAF-exposed embryonic zebrafish but yolk sac edema was similar in all exposures. Shelter-seeking behavior was decreased by dilbit and conventional crude WAF exposures, and continuous swimming behavior was affected by all tested WAF exposures. Regardless of WAF type, monoaromatic hydrocarbon content (largely made up of benzene, toluene, ethylbenzene, and xylene (BTEX)) was a more accurate predictor of lethality and pericardial edema than polycyclic aromatic hydrocarbon (PAH) content. Our results suggest that the toxicity of dilbit to a model fish is less than or similar to that of conventional crudes.
authors.affiliation: Department of Biological Sciences University of Alberta , Edmonton, Alberta T6G 2E9, Canada.
authors.forename: Danielle A
authors.initials: DA
authors.lastname: Philibert
authors.affiliation: Department of Biological Sciences University of Alberta , Edmonton, Alberta T6G 2E9, Canada.
authors.forename: Clara P
authors.initials: CP
authors.lastname: Philibert
authors.affiliation: Department of Biological Sciences University of Alberta , Edmonton, Alberta T6G 2E9, Canada.
authors.forename: Carlie
authors.initials: C
authors.lastname: Lewis
authors.affiliation: Department of Biological Sciences University of Alberta , Edmonton, Alberta T6G 2E9, Canada.
authors.forename: Keith B
authors.initials: KB
authors.lastname: Tierney
mesh_terms: D000818:Animals; D010578:Petroleum; D059392:Petroleum Pollution; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D015027:Zebrafish
chemical_list: D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical