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PARTICULATE MATTER SOILING OF EXTERIOR PAINTS AT A RURAL SITE
Citation:
Haynie, F. AND T. Lemmons. PARTICULATE MATTER SOILING OF EXTERIOR PAINTS AT A RURAL SITE. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-90/220 (NTIS PB91117184).
Description:
A soiling study was performed at an air monitoring site operated by the Research Triangle Institute in the relatively rural environmental conditions within Research Triangle Park, N.C. he study was designed to determine how various environmental factors contribute to the rate of soiling of white painted surfaces. ignificant factors that were monitored were hourly rainfall and wind speed, and weekly data for dichotomous sampler measurements nd total suspended matter concentrations. loss and flat white paints on hardboard were exposed vertically and horizontally, both protected and unprotected from rain for 16 weeks. easurements of exposed samples were taken at two, four, eight, and 16 weeks. eflectance was measured and scanning electron microscopy (SEM) stubs, which had been flush-mounted into the hardboard prior to painting, were removed at these times. article size distrbutions were determined by scanning electron microscopy. ajor findings were; (1) reflectance change on sheltered surfaces was proportional to the fraction of the surface area covered by particles, (2) coarse mode particles contribute more than fine mode particles to soiling of both horizontal and vertical surfaces, (3) insoluble fine mode particles are not significantly washed off by rain, and (4) rain interacts with soluble particles to contribute to soiling by "staining" the surface.