The application of portable air cleaners in spaces occupied by vulnerable people during wildfire events

Document Type


Publication Date

Summer 6-30-2023


In this study, PM2.5 concentrations were collected and documented during wildfire smoke impacted days using PurpleAir PA-II sensors at three different locations in a community located in the northwestern United States. Each location was comprised of three co-located sensors with one sensor positioned outdoors, one sensor indoors, and one sensor indoors with an air cleaner in the room. The relationship between both indoor and outdoor PM2.5 concentrations provided evidence on the effectiveness of sheltering indoors from wildfire smoke events with and without an air purification system.


MAIN AUTHOR: Mr. Layne Willis is a graduate student at Montana Tech. Layne earned his bachelor’s degree in civil engineering at MSU and, recently, his master’s degree in industrial hygiene. Layne worked with Drs. Dan Autenrieth and Julie Hart in the Department of Safety, Health, and Industrial Hygiene. Layne completed his research on the effectiveness of low-tech, low-cost air purification systems for vulnerable populations in the Butte area during wildfire smoke events. Working with the Bute Silver-Bow Health Department, the team identified three groups: senior citizens at the Springs, the young at Butte Head Start, and the underprivileged at the Butte Rescue Mission. Layne had to first meet his population on a personal level. He placed air monitors and air purifiers in specific locations for two months. Air quality measurements were taken during the two-month smoke season in residences with air purifiers. Findings revealed that staying indoors reduces exposure, and the air purifiers further reduced exposure to harmful air pollutants. The research provides evidence of effective and affordable interventions for disadvantaged and vulnerable citizens.