HR: 0830h
AN: A51F-0737    [PDF]
TI: Interactions of Trace Atmospheric Species With Urban Surface Films
AU: * Chaudhuri, S
EM: schaudhu@chem.utoronto.ca
AF: Department of Chemistry University of Toronto, 80 St. George St., Toronto, Ont M5S 3H6 Canada
AU: Donaldson, D
EM: jdonalds@chem.utoronto.ca
AF: Department of Chemistry University of Toronto, 80 St. George St., Toronto, Ont M5S 3H6 Canada
AB: Understanding and modelling episodes of urban air pollution is of increasing importance as the global population in urban centres approaches 50% and rises to 75% in greater developed regions. Recent field and laboratory measurements have confirmed the existence of organic films on impervious urban surfaces (such as windows, structures and roadways) and aerosol particles. Characterization of these films indicate organic species from both biogenic and anthropogenic emission sources. Despite urban areas being characterized by high concentrations of atmospheric pollutants and impervious surfaces, the potential role of surface films in controlling the fate and distribution of urban contaminants has not been explored experimentally. We have constructed a Knudsen cell apparatus coupled to a quadrupole mass spectrometer to study the reactive and unreactive uptake of trace atmospheric gases onto organic films. Our first study investigates low vapor pressure organic substrates and gas phase species, including smaller polycyclic aromatic hydrocarbons, representative of atmospheric constituents. Preliminary results indicate an appreciable uptake coefficient of naphthalene on oleic acid, on the order of 10-3. The results obtained to date, as well as their atmospheric implications, will be discussed.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0317 Chemical kinetic and photochemical properties
DE: 0345 Pollution--urban and regional (0305)
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting