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EVALUATION OF AIR PURIFICATION DEVICES FOR CONTROL OF INDOOR PM
Citation:
Buckley, T J. AND L A. Wallace. EVALUATION OF AIR PURIFICATION DEVICES FOR CONTROL OF INDOOR PM. Presented at PM 2000 AWMA Conference, Charleston, SC, January 24-28, 2000.
Impact/Purpose:
The main objective is to investigate human exposure to fine and coarse particles (and PAHs) from several important sources such as cooking, woodsmoke, and household cleaning. A second objective is to investigate the observed increased personal exposure (compared to indoor air concentrations measured by a fixed monitor) to particles: the so-called "personal cloud," that has been observed in many occupational and some environmental studies. A third objective is to incorporate the findings into a mass-balance indoor air quality model.
Description:
Because people spend most of their time indoors (89%), the indoor environment is a primary determinant of particle exposure. The indoor environment is especially an important determinant for the very young, the very old, and those with underlying cardiopulmonary disease because these population subgroups may spend an even larger fraction of their time indoors and they are susceptible to adverse effects from particle exposure. The concentration of PM indoors can be controlled by reducing their generation or increasing their removal. Commercial home air purifiers are a potential means for increasing removal. The purpose of this study was to evaluate the effectiveness of a 350 cfin HEPA air purifier for reducing indoor PM concentrations in an occupied residence. We conducted a single home (385 m3, 3-story townhouse) longitudinal study to investigate the effectiveness of a commercial home air purifier. Indoor particles were generated by typical activities including cooking, cleaning, and incense and candle burning, which were recorded on an indoor air time-activity diary. Particles ranging in size from 0.010 to 20 ,um were measured using a Scanning Mobility Particle Sizer (TS1, Inc, St.Paul, MN), an Aerodynamic Particle Sizer (TSI, St. Paul, MN)and a laser particle counter (Climet CI-500). The effectiveness of the home air cleaner was evaluated based on the depression in steady state particle concentration associated with the activation and deactivation of the room air purifier. Indoor air 12-h exchange rates were measured using a Bruel & Kjaer Model 1302 SF6 monitor (Bruel & Kjaer, Denmark). Results suggest that the effectiveness of the purifier is particle size dependent, yielding a decrease in a 3m X 4m room ranging from 10% to 40% for ultrahne particles and 80% for particles from 0.5 to 10 ,um. These results suggest that HEPA air purifiers with high air flow rates are effective in reducing indoor PM and that such devices may provide an effective tool for protecting susceptible populations such as asthmatics or persons with chronic obstructive pulmonary disease.
This work has been funded 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 recormnendation for use.