PARENT SESSION
WA4 - Passive Samplers for POPs
Chair: Harner, Tom1, 1 Environment Canada, Downsview, ON
Co-chair: Jones, Kevin2, 2 Lancaster University, Lancaster, LA1 4YQ
8:00 AM to 12:00 PM - Wednesday, 20 November 2002
Room Ballroom F
(515) Passive Air Sampling of Persistent Organic Pollutants Across North America.
Wania, Frank*,1, Shen, Li1, Lei, Ying1, Teixeira, Camilla2, Muir, Derek2, 1 University of Toronto at Scarborough, Toronto, Ontario, Canada2 National Water Research Institute, Burlington, Ontario, Canada
ABSTRACT- The large-scale distribution patterns of persistent organic pollutants in the North American atmosphere were characterized by using a novel XAD-resin-based passive air sampling technique. The network designed for this study consisted of more than a hundred passive air samplers which were deployed for an entire year (spring/summer 2000 to spring/summer 2001) at 43 stations in five countries across North America, covering 72 degrees of latitude and longitude. These stations were chosen as remote as possible, representing a wide range with respect to climatic conditions and proximity to various potential source regions and preferential atmospheric transport pathways. The analysis of the passive air sampling data shows clear differences of absolute concentrations of organochlorine pesticides and polychlorinated biphenyls (PCBs) with latitude, longitude, and between urban, rural and remote sites in the North American atmosphere. Absolute levels and relative composition of pesticide mixtures such as the HCHs, DDT-related compounds and chlordanes reflect current and past use in an area. The PCBs show an enhancement of the more volatile constituents at higher latitudes, consistent with the global fractionation hypothesis. Passive samplers are an efficient and simple means of obtaining a large scale picture of the continental atmospheric distribution of persistent organic compounds.
Key words: passive air sampling, persistent organic pollutants, North America, atmospheric long range transport