Spatial trends of perfluoroalkyl compounds in ringed seals ( Phoca hispida ) from the Canadian Arctic

• Published in: Environmental Toxicology and Chemistry
• Main Authors: Butt, Craig M., Mabury, Scott A., Kwan, Michael, Wang, Xiaowa, Muir, Derek C.G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2008
• Subjects: Health, Toxicology and Mutagenesis; Environmental Chemistry; Arctic Archipelago; Arctic; Arviat; Baffin Island; Baffin; Canadian Arctic Archipelago; Cumberland Sound; Gjoa Haven; Grise Fiord; Hudson Bay; Inukjuak; Nain; Phoca hispida; Qikiqtarjuaq
• Online Access: http://dx.doi.org/10.1897/07-428.1; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1897%2F07-428.1; https://setac.onlinelibrary.wiley.com/doi/pdf/10.1897/07-428.1

Abstract The present study examined spatial trends of perfluoroalkyl compounds (PFCs) in liver samples from 11 populations of ringed seals ( Phoca hispida ) in the Canadian Arctic from 2002 to 2005. Trophic position and relative carbon sources were compared by analyzing stable nitrogen and carbon isotopes in muscle samples. Geometric mean concentrations of total C 9 –C 15 perfluorinated carboxylates (PFCAs) ranged from 8.8 to 84 ng/g wet weight, and C 9 –C 11 PFCAs predominated. Perfluorooctane sulfonate was the dominant PFC measured, with concentrations ranging from 6.5 to 89 ng/g wet weight, contributing between 29 and 56% of the total PFC concentration. Overall, mean PFC concentrations were similar between populations, and differences were attributed largely to elevated levels in the Gjoa Haven (Rae Strait, central Canadian Arctic archipelago) and Inukjuak populations (eastern Hudson Bay) and to lower concentrations at Pangnirtung (Cumberland Sound, Baffin Island). Mean stable nitrogen isotope ratios (±95% confidence intervals) ranged from 14.7‰ (±0.3‰) at Nain (Labrador) to 17.9‰ (±0.7‰) at Gjoa Haven, suggesting that all populations were within the same trophic level. Stable carbon isotope ratios varied widely between the seal populations, ranging from —22.9‰ (±0.2‰) at Gjoa Haven to — 17.7‰ (±0.4‰) at Nain. The δ 13 C ratios from Gjoa Haven were significantly more depleted than those for other populations and may suggest a terrestrially based carbon source. The depleted stable carbon isotope ratio may explain the elevated PFC concentrations in the Gjoa Haven population. Analysis of covariance indicated that δ 13 C was a significant covariable for seven of nine seal populations for which δ 13 C values were available. After adjusting for δ 13 C values, concentrations of most PFCs generally were statistically greater in the Grise Fiord, Qikiqtarjuaq, Arviat, and Nain populations.