Seasonal changes and relations between levels of organochlorines in arctic ambient air: First results of an all-year-round monitoring program at Ny-Alesund, Svalbard, Norway

The influence of seasonal changes and long-range transport on levels of selected polychlorinated compounds was studied by taking ambient air samples at Ny-Alesund (78 degrees 55' N, 11 degrees 56' E), Svalbard, Norway, once a week from March to October 1993 and with 48-h sampling intervals from November to December 1993. Polychlorinated pesticides such as chlordanes, hexachlorocyclohexanes (HCH), and DDT compounds as well as polychlorinated biphenyl (PCB) congeners were quantified by high-resolution gas chromatography combined with high- or low-resolution mass spectrometry. Due to levels being often in the subpicogram per cubic meter range, a comprehensive quality control program was applied. This first continuous measurement campaign in the Norwegian Arctic showed a clear seasonal variation of trans-chlordane and cis-nonachlor. Circumpolar trajectories allowed identification of long-range transport from different source regions. The temporal concentration profiles of compounds with different industrial and agricultural sources allowed us to confirm such transport episodes and to differentiate between the influence of industrial and agricultural areas. A significant correlation was found between concentrations of some chlordane congeners, alpha- and gamma-HCH isomers, and the most volatile PCB congeners. No seasonal change of the PCB concentrations was found, indicating that a weekly average temperature of 5-8 degrees C during summer is not large enough for a measurable revolatilization of already deposited material.