An assessment of the toxicological significance of anthropogenic contaminants in Canadian arctic wildlife

• Published in: Science of The Total Environment
• Main Authors: Fisk, Aaron T., De Wit, Cynthia A., Wayland, Mark, Kuzyk, Zou Zou, Burgess, Neil, Letcher, Robert, Braune, Birgit, Norstrom, Ross, Blum, Susan Polischuk, Sandau, Courtney, Lie, Elisabeth, Larsen, Hans Jørgen S., Skaare, Janneche Utne, Muir, Derek C.G.
• Format: Text
• Language: unknown
• Published: Scholarship at UWindsor 2005
• Subjects: Arctic; Biological effects; Cadmium; Canadian arctic; DDT; Fish; Heavy metals; Mammals; Mercury; Organochlorines; PCB; PCDD/F; Seabirds; Selenium; Nunavut; Saglek Bay; Beluga; Beluga whale; Beluga*; Burbot; Cepphus grylle; Common Eider; Delphinapterus leucas; Somateria mollissima; Ursus maritimus
• Online Access: https://scholar.uwindsor.ca/glierpub/426; https://doi.org/10.1016/j.scitotenv.2005.01.051

Anthropogenic contaminants have been a concern in the Canadian arctic for over 30 years due to relatively high concentrations of bioaccumulating and biomagnifying organochlorine contaminants (OCs) and toxic metals found in some arctic biota and humans. However, few studies have addressed the potential effects of these contaminants in Canadian arctic wildlife. Prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects related to contaminant exposure, and compares new tissue concentration data to threshold effects levels. Weak relationships between cadmium, mercury and selenium burdens and health biomarkers in common eider ducks (Somateria mollissima borealis) in Nunavut were found but it was concluded that metals were not influencing the health of these birds. Black guillemots (Cepphus grylle) examined near PCB-contaminated Saglek Bay, Labrador, had enlarged livers, elevated EROD and liver lipid levels and reduced retinol (vitamin A) and retinyl palmitate levels, which correlated to PCB levels in the birds. Circulating levels of thyroid hormones in polar bears (Ursus maritimus) were correlated to PCB and HO-PCB plasma concentrations, but the impact at the population level is unknown. High PCB and organochlorine pesticide concentrations were found to be strongly associated with impaired humoral and cell-mediated immune responses in polar bears, implying an increased infection risk that could impact the population. In beluga whale (Delphinapterus leucas), cytochromes P450 (phase I) and conjugating (phase II) enzymes have been extensively profiled (immunochemically and catalytically) in liver, demonstrating the importance of contaminants in relation to enzyme induction, metabolism and potential contaminant bioactivation and fate. Concentrations of OCs and metals in arctic terrestrial wildlife, fish and seabirds are generally below effects thresholds, with the possible exception of PCBs in burbot ...