Temporal trends of emerging pollutant deposition through ice core sampling on the Devon Ice Cap

Two 15 - 20 m ice cores were collected near the summit of the Devon Ice Cap in late April - early May of 2015. Samples were shipped frozen to Environment Canada in Burlington, Ontario. Ice core dating will be done through in situ borehole 137Cs gamma spectroscopy to locate the depth of the 1963 atomic bomb test layer at the coring site. Density measurements above that level will allow determination of the total mass accumulation of snow since 1963 and, consequently, the deposition rate. The accuracy of this method is 1 - 2 years. The ice cores will be sectioned and extracted in a clean room (with Carbon and HEPA filtered air and positively pressured relative) at Canada Centre for Inland Waters (Environment Canada Burlington) to minimize the potential for contamination. One core will be analyzed for new perfluoroalkyl substances (PFAS) and the other for organophosphate flame retardants (OPFR). The temporal trends in atmospheric deposition will be compared to known changes in production of PFASs and OPFRs. We will also use back trajectories to determine if different areas acted as sources to the Devon Ice Cap in different years. This will allow us to understand the sources and long-range transport mechanisms for these compounds.