The Recalcitrance and Toxicity of Polycyclic Aromatic Hydrocarbons within Crude Oil Residues in Beach Sediments at the Bios Site, Nearly Forty Years Later

Abstract

Sites of the Baffin Island Oil Spill (BIOS) project (Cape Hatt, Baffin Island, Canadian Arctic) were revisited nearly 40 years after the original oil application to provide long-term monitoring data for Arctic oil spill research. Surface and subsurface sediment samples were collected from the intertidal zone of the 1981 nearshore oil spill experiment (Bay 11), from 1980 supratidal control plots (Crude Oil Point) and 1982 supratidal treatment plots (Bay 106). Samples were analyzed for Polycyclic Aromatic Hydrocarbons (PAHs) and alkylated homologues using an Agilent 7010B Triple Quadrupole GC/MS system in the MRM mode. Our results suggest that total mean concentrations of all monitored PAHs range from 0.05 – 14 mg/kg, whereas total mean concentrations of the 16 EPA priority PAHs range from 0.003 – 3 mg/kg. All three sites featured samples where concentrations of various priority PAHs exceeded the established Interim Marine Sediment Quality Guidelines. All supratidal samples contained potentially toxic levels of PAHs. Even after nearly four decades of weathering, the recalcitrant crude oil residues remain a potential hazard for the native organisms. Continued monitoring of this unique study site is crucial for establishing a timeline for oil degradation, and to observe a reduction in toxicity over time.

Keywords: Arctic, Oil, Weathering, Sediment Quality Guidelines, Long-term Monitoring, Baffin Island Oil Spill project