Impact of Do-It-Yourself and Commercial Air Cleaner Use on Residential PM2.5 in a Smoke-Impacted Community

PRADEEP PRATHIBHA, Mallory Turner, Madison Kirshner, Amber Batchelder, Brian McCaughey, Julia Carlstad, Ann Chelminski, Ana Rappold, Beth Hassett-Sipple, Amara Holder, U.S. Environmental Protection Agency

     Abstract Number: 325
     Working Group: Biomass Combustion: Outdoor/Indoor Transport and Indoor Air Quality

Abstract
Low-cost, Do-It-Yourself air cleaners (“DACs,” MERV13 electrostatic filter attached to a box fan) are an affordable alternative to commercial air cleaners (“CACs”) to reduce residential exposure to particulate matter in wildfire-impacted areas. However, air quality improvements may vary with user behavior. In this pilot study, we evaluated the impact of air cleaner use on PM_2.5 and change in air cleaner usage due to an air quality display (“AQD”) in a smoke-impacted community in Hoopa, CA.

We measured indoor and outdoor PM_2.5 to characterize (1) infiltration ratio (“IR”) during the wildfire season (“FS,” n=6 homes) and (2) all indoor PM_2.5 during winter (“WS,” n=11 homes), when woodstove use is prevalent. We monitored baseline air quality, then sequentially provided a DAC, a CAC and, finally, an AQD with which participants used their preferred air cleaner. Then, mixed linear models were used to quantify associations [95% CI] of air cleaner use (logged with power meters) with IR (FS only) and 10-min mean indoor PM_2.5.

During FS, relative to the baseline, IR was 21.4% [7.1-33.5] and 7.6% [0.3-14.4] lower when DAC and CAC were running, respectively. Infiltrated PM_2.5 was 21.5% [16.5-26.3] and 19.9% [15.2-24.4] lower in DAC and CAC phases, respectively. Similarly, during WS, DAC and CAC use were associated with 10.0% [8.5-11.6] and 14.9% [13.2-16.7] reduction in indoor PM_2.5, respectively. Finally, air cleaner use was 28-33% lower during AQD phase.

While both cleaners reduced indoor PM_2.5, participant adherence to usage instructions in DAC and CAC phases (≥8 hours while home) varied. The CAC was sometimes run continuously, but the DAC was operated less than instructed, with noise being the most common complaint. Organizations in smoke-impacted communities should account for this behavioral aspect when developing approaches to mitigate exposure to indoor PM_2.5.

Disclaimer: Does not reflect EPA views/policy.