title: Detoxification, endocrine, and immune responses of tree swallow nestlings naturally exposed to air contaminants from the Alberta oil sands.
abstract: Changes in environmental and wildlife health from contaminants in tailings water on the Canadian oil sands have been well-studied; however, effects of air contaminants on wildlife health have not. A field study was conducted to assess biological costs of natural exposure to oil sands-related air emissions on birds. Nest boxes for tree swallows (Tachycineta bicolor) were erected at two sites; within 5 km of active oil sands mining and extraction, and ≥ 60 km south, at one reference site. Passive air monitors were deployed at the nest boxes to measure nitrogen dioxide, sulfur dioxide, ozone, volatile organic compounds, and polycyclic aromatic hydrocarbons (PAHs). Nestlings were examined at day 9 post hatching to assess T cell function and morphometry. At day 14 post hatching, a subset of nestlings was euthanized to measure detoxification enzymes, endocrine changes, and histological alterations of immune organs. Except for ozone, all air contaminants were higher at the two oil sands sites than the reference site (up to 5-fold). Adult birds had similar reproductive performance among sites (p>0.05). Nestlings from industrial sites showed higher hepatic ethoxyresorufin O-dealkylase (EROD) induction (p<0.0001) with lower relative hepatic mass (p=0.0001), a smaller T cell response to the phytohemagglutinin skin test (p=0.007), and smaller bursae of Fabricius (p<0.02); a low sample size for one site indicating lower body condition scores (p=0.01) at day 14 warrants cautious interpretation. There were no differences among nestlings for feather corticosterone (p>0.6), and no histological alterations in the spleen or bursa of Fabricius (p>0.05). This is the first report examining toxicological responses in wild birds exposed to air contaminants from industrial activity in the oil sands. It is also the first time that small, individual air contaminant monitors have been used to determine local contaminant levels in ambient air around nest boxes of wild birds.
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW Calgary, Alberta T2N 4Z6, Canada. Electronic address: luis.cruzmartinez@ucalgary.ca.
authors.forename: Luis
authors.initials: L
authors.lastname: Cruz-Martinez
authors.affiliation: Ecotoxicology & Wildlife Health Division, Science & Technology Branch, Environment Canada, 867 Lakeshore Rd., Burlington, Ontario L7R 4A6, Canada. Electronic address: kim.fernie@ec.gc.ca.
authors.forename: Kim J
authors.initials: KJ
authors.lastname: Fernie
authors.affiliation: Ecotoxicology & Wildlife Health Division, Science & Technology Branch, Environment Canada, 115 Perimeter Road, Saskatoon, Saskatchewan S7N 0X4, Canada. Electronic address: catherine.soos@ec.gc.ca.
authors.forename: Catherine
authors.initials: C
authors.lastname: Soos
authors.affiliation: Air Quality Processes Research Section, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada. Electronic address: tom.harner@ec.gc.ca.
authors.forename: Tom
authors.initials: T
authors.lastname: Harner
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW Calgary, Alberta T2N 4Z6, Canada. Electronic address: fgetache@ucalgary.ca.
authors.forename: Fitsum
authors.initials: F
authors.lastname: Getachew
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW Calgary, Alberta T2N 4Z6, Canada. Electronic address: judit.smits@ucalgary.ca.
authors.forename: Judit E G
authors.initials: JE
authors.lastname: Smits
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D000416:Alberta; D000818:Animals; D003345:Corticosterone / Q000378:metabolism; D004703:Endocrine System / Q000187:drug effects; D004784:Environmental Monitoring; D005241:Feathers / Q000378:metabolism; D007220:Industrial Waste / Q000032:analysis / Q000706:statistics & numerical data; D061329:Oil and Gas Fields; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D012098:Reproduction / Q000187:drug effects; D046388:Swallows / Q000276:immunology / Q000502:physiology*
chemical_list: D000393:Air Pollutants; D007220:Industrial Waste; D011084:Polycyclic Aromatic Hydrocarbons; D003345:Corticosterone
keywords: Air contaminants; Avian bioindicators; Ecotoxicology; Immunotoxicology; Oil sands; Sentinel wildlife