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(15-15) Multimedia conentrations of semi-volatile organic compounds (SOCs) along an urban-rural gradient. Liu, Qintao*,1, Diamond, Miriam1, Stern, Gary2, McCarry, Brian3, 1 University of Toronto, Environmental Research Group, Toronto, Ontario, Canada2 Department of Fisheries and Oceans, Winnipeg, Manitoba, Canada3 Department of Chemistry, Hamilton, Ontario, Canada ABSTRACT- Chemical concentrations of n-alkanes, PAH, PCBs and OC pesticides were measured simultaneously in five media at urban, suburban and rural sites in early and late summer and winter. Urban and suburban sites were located in Hamilton, Canada, that has one of the largest urban industrial complexes in North America which includes two major steel plants. The rural site was located in a nearby agricultural area. The media sampled included air (gas and particle phases), surface water (dissolved and suspended phases), surface soil, vegetation (tree leaves), and the organic film on glass windows where the windows are a conveniently sampled impervious surface. Concentrations of all chemicals were highest in the organic film, followed by soil and vegetation. Concentrations of most chemicals were over 10 times higher at the urban relative to the rural site. Fresher PCB and OC pesticide signals were found at urban versus rural sites: for anthropogenic chemicals the urban area is the sources whereas the rural location is a receptor. Concentrations varied seasonally with, for example, higher concentrations in tree leaves in June than August, which is indicative of seasonal fluctuations in air concentrations and the aging of the leaf cuticular layer. In contrast, the chemical composition of anthropogenically-derived compounds did not vary seasonally at the urban (source) site but did at the rural (receptor) site in response to seasonal patterns in atmospheric transport. Key words: air, water, vegetation, soil, impervious surfaces, PAH, PCBs, OC pesticides |
