Investigating the occurrence and accumulation of perfluoroalkylated substances and other persistent organic pollutants in snow and ice of the Earth’s Polar regions

• Main Authors: Garnett, Jack, Halsall, Crispin, Wynn, Peter, Leeson, Amber
• Format: Thesis
• Language: English
• Published: Lancaster University 2021
• Subjects: Antarc*; Antarctica; Arctic; Climate change; East Antarctica; Sea ice
• Online Access: https://eprints.lancs.ac.uk/id/eprint/159595/; https://eprints.lancs.ac.uk/id/eprint/159595/1/2021GarnettPhD

Persistent organic pollutants (POPs) are a highly diverse group of synthetic chemicals that are released into the environment from human activities and display a host of adverse effects in wildlife and humans. Perfluoroalkylated substances (PFASs) are one major group of industrial chemicals that are globally produced in vast quantities and are subject to various global regulations. However, PFASs are present in the Earth’s Polar Regions and yet little is known about their environmental fate and behaviour, particularly their accumulation and fate in snow and ice and the wider cryosphere. Moreover, climate change is altering the cryosphere, affecting sea ice and its properties for example, which in turn may affect the biogeochemical cycling of these pollutants and could lead to altered or enhanced biological exposure and uptake. This thesis examines the accumulation of PFASs in snow and firn as a useful recorder of environmental contamination in Antarctica, a region which lacks a multi-decadal time series of air monitoring data. The thesis also investigates in detail the processes that result in the uptake, distribution and accumulation of persistent organic pollutants in sea ice, particularly in the context of a warmer Arctic, where sea ice is now dominated by brine-rich single season ice. There is a lack of monitoring data on the levels of PFASs in Antarctica, and so a snow core was taken from Kohnen Station (East Antarctica plateau) to determine the historical deposition rates in the region. Results revealed low or non-detectable levels of perfluorosulfonic acids (PFSAs) but showed increasing trends of perfluorocarboxylates (PFCAs) between 1958 – 2017. Deposition rates for PFCAs in snow varied depending on chain length, with PFBA (C4) showing up to 2-orders of magnitude higher (1.3 and 280 ng m-2 yr-1) than PFOA (C8) (1.6 and 12.6 ng m-2 yr-1). Furthermore, correlations between PFCAs of varying chain length were strong (r2 > 0.7, p < 0.01). This information suggests that PFASs in the remote polar region, ...