Finding F-1419

“In comparison, during HEPA portable air cleaner use, households had, on average, a 4.50% lower indoor PM2.5 concentration (95% CI: −6.30%, −2.66%), after accounting for repeated measures within homes.”

Teigen et al. A two-year indoor–outdoor monitoring study of household clean air interventions during ambient and wildfire smoke periods in King County, Washington (2026). Environ Res Commun. Page 9. CKB 1611

Structure

Factor: Particulate matter (PM₂.₅ and PM₁₀)
Intervention: Air purifiers
Setting: home
Study design: two-year indoor and outdoor monitoring study of households: indoor fine particulate matter measured continuously while households used a commercial portable high efficiency air cleaner and, in other periods, a do-it-yourself box fan filter kit, with mixed models accounting for repeated measures within homes (class 3)
Effect: difference 4.50 (-6.30–-2.66)
Caveat: the difference is printed as negative and the estimate is recorded as its size with the direction in its own field

A Finding records what one published document states, verbatim and with its page. It is not a conclusion of Coridum; see the Claims that build on it.