AIR MONITORING IN THE ARCTIC - RESULTS FOR SELECTED PERSISTENT ORGANIC POLLUTANTS FOR 1992

The Arctic is generally considered to be a pristine environment and ha s few direct inputs of organochlorine compounds (OCs), including pesti cides, herbicides, polychlorinated biphenyls, or polycyclic aromatic h ydrocarbons (PAHs). In spite of this, airborne concentrations of persi stent organic pollutants (POPs) are comparable to those in more popula ted and industrialized regions of North America and Europe. Atmospheri c transport and condensation of compounds at low temperature condition s are important factors contributing to the presence of contaminants i n the Arctic. A long-term program has been established to measure the airborne concentrations of POPs in the Arctic. The first station at Al ert was established in January 1992. The concentrations measured in th e first year of monitoring for 18 compounds that are representative of different compound classes are presented. Seasonal variations for PAH s are similar to those for Arctic haze and peak during winter. For exa mple, in the coldest period, October to April, benzo[a]pyrene concentr ations were found to average 20 pg/m(3), whereas, in contrast, during the relatively warm May to September period, average levels were 1.0 p g/m(3). For OCs, the seasonal cycle was not as pronounced as that for PAH compounds. For example, alpha-hexachlorocyclohexane was found at A lert at average concentrations of 62 and 57 pg/m(3), respectively, dur ing cold and warm periods. It is postulated that air concentrations ar e influenced by advection from distant source regions as well as excha nge with local (Arctic Ocean) surfaces.