Spatial and Temporal Variation of Polycyclic Aromatic Hydrocarbons in the Arctic Atmosphere

In the first multi-year arctic air sampling program, PAHs were sampled (vapor and particulate) every week at three locations in the Canadian and Russian Arctic. Data are presented here for the years 1992−1994. The geometric mean ∑PAH concentrations (where ∑ = 16 compounds) for 1993 ranged from 249 to 508 pg/m3 for the three sites. Clear seasonality was evident with the highest concentrations oc curring during the colder months of October−April, coinciding with the arctic haze period. PAH concentrations during this period were highest in the order of Dunai (Russian) > Alert (high Arctic) > Tagish (Pacific). Air mass back trajectories computed for February 1994 revealed long-range transport from Eurasia into the high Arctic. Short periods of high concentrations were also evident during the warmer months, most notably at the Tagish site, where elevated levels of retene (a marker for soft wood combustion) matched forest fire records. Initial findings suggest that the gas/particle partitioning of some of the lighter PAHs, examined during the colder haze period, is similar to remote temperate studies and in reasonable agreement to the Junge−Pankow adsorption model.