Finding F-1417

“Overall, HEPA air cleaners significantly reduce the indoor PM2.5 level (33.5 ± 10.3 vs. 17.2 ± 10.7 μg/m3, mean difference (MD) = −16.3 μg/m3, p < 0.001) and indoor/outdoor PM2.5% (76.3 ± 16.8 vs. 38.6 ± 19.8%, MD = −37.7%, p < 0.001).”

Chen et al. Efficacy of HEPA Air Cleaner on Improving Indoor Particulate Matter 2.5 Concentration… (2022). International journal of environmental research and public health. Page 1. CKB 8751

Structure

Factor: Particulate matter (PM₂.₅ and PM₁₀)
Intervention: Air purifiers
Setting: home
Study design: field study of portable high efficiency particulate air cleaners in households: indoor and outdoor fine particulate matter monitored continuously with laser light dispersion sensors before and during filtration, across machines and flow settings (class 3)
Effect: mean
Caveat: the spread after filtration is 10.7 μg/m3 and the sentence prints both as plus-minus values without naming them; the strongest effect was in three machines on the medium-flow setting, -26.5 μg/m3

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.