The recent depositional trend of polycyclic aromatic hydrocarbons and elemental carbon to the Agassiz Ice Cap, Ellesmere Island, Canada

Polar ice caps can provide long-term records of atmospheric deposition. Owing to the prevalent conditions, the layers of accumulated snow are subject to little chemical or physical change and are temporally well defined. Sampling of the Agassiz Ice Cap on Ellesmere Island was undertaken in early 1993 to investigate the potential of polar ice caps for use in determining recent historical trends in the deposition of anthropogenic contaminants to the Arctic. Discrete annual snow and ice layers representing the last 30 years of accumulation were sampled from a deep pit to obtain large volume samples for the determination of polycyclic aromatic hydrocarbons (PAHs) and elemental carbon (EC). The flux of PAHs to the ice cap has remained relatively constant for the past 20 years, with a mean value of 11 (± 6) μg/m2/year. This equates to a total annual loading of PAH to the Arctic of 37 t/year for the same period. Prior to this period, a greater flux of 74 (± 20) μg/m2/year is observed. Mean values for EC concentration and flux were found to be 2.6 (± 2.8) μg/l and 310 (± 370) μg/m2/year, respectively. However, analytical complications were encountered with the analysis of EC, and these data should be considered as preliminary baseline values only.