PhD Candidate, Griffith University
Once regarded as pristine regions, the Polar Regions may become the largest sources of pollution
Persistent organic pollutants (POPs) are synthetic compounds that resist degradation and bio-accumulate in, and become toxic to, living organisms. Owing to the physiochemical properties of POPs, Polar Regions harbour substantial quantities of them. Climate change, exacerbated in Polar Regions, stands to significantly alter Polar transport and fate of these chemicals necessitating concerted research efforts . This project will broaden the information base surrounding chemical contamination in Antarctica through screening of archived air samples. Further, the project will target the oceanic environmental transport pathway, investigating the role of the unique circulation systems surrounding the Antarctic in effective north to south transport of hydrophobic perfluorinated POPs. Finally, the study will perform some of the first empirical measurements of POPs Polar ice-sheets with the purpose of evaluating this environmental reservoir, and potential source of POPs, under conditions defined by net cryosphere loss.
Abstract: The relative importance of atmospheric versus oceanic transport for poly- and perfluorinated alkyl substances (PFASs) reaching the Arctic Ocean is not well understood. Vertical profiles from the Central Arctic Ocean and shelf water, snow and meltwater samples were collected in 2012; 13 PFASs (C6-C12 PFCAs; C6, 8, 10 PFSAs; MeFOSAA and EtFOSAA, and FOSA) were routinely detected (range: <5 - 343 pg/L). PFASs were only detectable above 150 m depth in the polar mixed layer (PML) and halocline. Enhanced concentrations were observed in snow and meltpond samples, implying atmospheric deposition as an important source of PFASs. Model results suggested atmospheric inputs to account for 34-59% (~11-19 pg/L) of measured PFOA concentrations in the PML (mean 32±15 pg/L). Modeled surface and halocline measurements for PFOS based on North Atlantic inflow (11-36 pg/L) agreed with measurements (mean, 17, range <5-41 pg/L). Modeled deep water concentrations below 200 m (5-15 pg/L) were slightly higher than measurements (<5 pg/L), suggesting the lower bound of PFAS emissions estimates from wastewater and rivers may provide the best estimate of inputs to the Arctic. Despite low concentrations in deep water, this reservoir is expected to contain most of the PFOS mass in the Arctic (63-180 Mg) and projected to continue increasing to 2038.
Pub.: 18 May '17, Pinned: 29 Aug '17
Abstract: Perfluoroalkyl substances (PFASs) have been detected in organisms worldwide, including Polar Regions. The polar bear (Ursus maritimus), the top predator of Arctic marine ecosystems, accumulates high concentrations of PFASs, which may be harmful to their health. The aim of this study was to investigate which factors (habitat quality, season, year, diet, metabolic state [i.e. feeding/fasting], breeding status and age) predict PFAS concentrations in female polar bears captured on Svalbard (Norway). We analysed two perfluoroalkyl sulfonates (PFSAs: PFHxS and PFOS) and C8-C13 perfluoroalkyl carboxylates (PFCAs) in 112 plasma samples obtained in April and September 2012-2013. Nitrogen and carbon stable isotope ratios (δ(15)N, δ(13)C) in red blood cells and plasma, and fatty acid profiles in adipose tissue were used as proxies for diet. We determined habitat quality based on movement patterns, capture position and resource selection functions, which are models that predict the probability of use of a resource unit. Plasma urea to creatinine ratios were used as proxies for metabolic state (i.e. feeding or fasting state). Results were obtained from a conditional model averaging of 42 general linear mixed models. Diet was the most important predictor of PFAS concentrations. PFAS concentrations were positively related to trophic level and marine diet input. High PFAS concentrations in females feeding on the eastern part of Svalbard, where the habitat quality was higher than on the western coast, were likely related to diet and possibly to abiotic factors. Concentrations of PFSAs and C8-C10 PFCAs were higher in fasting than in feeding polar bears and PFOS was higher in females with cubs of the year than in solitary females. Our findings suggest that female polar bears that are exposed to the highest levels of PFAS are those 1) feeding on high trophic level sea ice-associated prey, 2) fasting and 3) with small cubs.
Pub.: 08 Jun '17, Pinned: 29 Aug '17
Abstract: Perfluoroalkyl substances (PFAS) are ubiquitous in the environment, including remote polar regions. To evaluate the role of snow deposition as an input of PFAS to Maritime Antarctica, fresh snow deposition, surface snow, streams from melted snow, coastal seawater and plankton samples were collected over a three-month period (December 2014 - February 2015) at Livingston Island. Local sources of PFASs were significant for perfluoroalkyl sulfonates (PFSAs) and C7-14 perfluoroalkyl carboxylates (PFCAs) in snow, but limited to the transited areas of the research station. The concentrations of 14 ionizable PFAS (∑PFAS) in freshly deposited snow (760 to 3600 pg L-1) were one order of magnitude higher than those in background surface snow (82 to 430 pg L-1). ∑PFAS ranged from 94 to 420 pg L-1 in seawater, and from 3.1 to 16 ng gdw-1 in plankton. Ratios of individual PFAS concentrations in freshly deposited snow relative to surface snow (CSD/CSnow), snowmelt (CSD/CSM), and seawater (CSD/CSW) were close to 1 (from 0.44 to 1.4) for all perfluorooctane sulfonate (PFOS) isomers, suggesting that snowfall does not contribute significantly to PFOS in seawater. Conversely, these ratios for PFCAs ranged from 1 to 33, and were positively correlated with the number of carbons in the PFCA alkylated chain. These trends suggest that snow deposition, scavenging sea-salt aerosol bound PFAS, plays a role as a significant input of PFCAs to the Maritime Antarctica.
Pub.: 01 Jul '17, Pinned: 29 Aug '17
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