Air monitoring in the arctic: Results for selected persistent organic pollutants for 1992

The Arctic is generally considered to be a pristine environment and has few direct inputs of organochlorine compounds (OCs), including pesticides, herbicides, polychlorinated biphenyls, or polycyclic aromatic hydrocarbons (PAHs). In spite of this, airborne concentrations of persistent organic pollutants (POPs) are comparable to those in more populated and industrialized regions of North America and Europe. Atmospheric transport and condensation of compounds at low temperature conditions are important factors contributing to the presence of contaminants in the Arctic. A long-term program has been established to measure the airborne concentrations of POPs in the Arctic. The first station at Alert was established in January 1992. The concentrations measured in the first year of monitoring for 18 compounds that are representative of different compound classes are presented. Seasonal variations for PAHs are similar to those for Arctic haze and peak during winter. For example, in the coldest period, October to April, benzo[a]pyrene concentrations were found to average 20 pg/m(3), whereas, in contrast, during the relatively warm May to September period, average levels were 1.0 pg/m(3). For OCs, the seasonal cycle was not as pronounced as that for PAH compounds. For example, alpha-hexachlorocyclohexane was found at Alert at average concentrations of 62 and 57 pg/m(3), respectively, during cold and warm periods. It is postulated that air concentrations are influenced by advection from distant source regions as well as exchange with local (Arctic Ocean) surfaces.