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CONTINUOUS MEASUREMENT OF PARTICLES (0.01-20.0 UM) IN AN OCCUPIED HOME, REED AND WALLACE, AAAR.
Citation:
HowardReed, C AND L A. Wallace. CONTINUOUS MEASUREMENT OF PARTICLES (0.01-20.0 UM) IN AN OCCUPIED HOME, REED AND WALLACE, AAAR. Presented at American Association of Aerosol Research, Tacoma, WA, October 11-15, 1999.
Description:
To better understand the contribution of outdoor and indoor sources to particle concentrations found in residential indoor air, an extensive monitoring effort has been undertaken in a three-story townhouse located in Reston, VA. Of particular interest was the determination of important indoor source's of particles for different size fractions. Data have been collected since November 1997 (SMPS) and April 1998 (APS) on particle concentrations and associated time activity information.
Typical household activities were found to generate particles spanning four orders of magnitude in size (0.01 u m 20 u m). A Scanning Mobility Particle Sizer (SMPS) was used to classify ultrafine particles (0.01 u m - 0.4 1 um) into 100 size categories. An Aerodynamic Particle Size (APS) was used to count particles in 52 channels from 0.3 um to 20 u m. The SMPS collected samples every five minutes and the APS collected samples every one minute. These relatively short sampling cycles provided detailed indoor particle concentration profiles including peak levels resulting from short bursts of activity. As a result, the dominant size fraction of particles and typical peak concentrations generated by typical household activities could be determined.
Sources that contributed the largest number of particles in this non-smoking home were combustion activities (candles, matches, incense) and cooking (frying, sauteeing, broiling, deep-frying, and stir-frying). Sources that generated ultrafine particles, as measured by the SMPS in this home, included the gas burners, gas oven, and electric toaster. The APS showed that combustion activities led to increases in primarily the fine particle size fractions (< 2.5 um) and cooking activities contributed to both fine and coarse fractions. Coarse particles were also generated during physical movement. Emission profiles of particle size and concentration were determined for about a dozen common indoor sources.
Decay rates were calculated for particles generated by a number of indoor sources. In some cases, concurrent calculation of air exchange rates using sulfur hexafluoride injection and photo acoustic detection (Bruel & Kjaer) allowed determination of deposition rates.
The research described in this abstract has been funded wholly or in part by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.