Evidence map›Paper›PMID 36454721›Full record

Trial reportPloS one2022

Effects of portable air cleaners and A/C unit fans on classroom concentrations of particulate matter in a non-urban elementary school.

Alexandra Azevedo, Jahred Liddie, Jason Liu, Jessica E Schiff, Gary Adamkiewicz, Jaime E Hart

Open access · goldAbstract readRandomized Controlled Trial
In one paragraph

Trial report in PloS one, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.6field-weighted citation impact, top 34% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 6 citations in OpenAlex.

  1. Review
  2. Article
  3. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 2 institutions in 1 country.

Alexandra AzevedoDepartment of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
Jahred LiddieDepartment of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
Jason LiuDepartment of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
Jessica E SchiffDepartment of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.ORCID 0000-0001-7916-5366
Gary AdamkiewiczDepartment of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
Jaime E HartDepartment of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
Harvard University · USBrigham and Women's Hospital · US

Funding

Translational Research Support CoreP30ES000002 · NIEHS · HARVARD UNIVERSITY (SCH OF PUBLIC HLTH) · PI JAIME ELIZABETH HART · 1985 to 2026
$44.6M
Training Program in Environmental EpidemiologyT32ES007069 · NIEHS · HARVARD UNIVERSITY (SCH OF PUBLIC HLTH) · PI LADEN, FRANCINE · 1985 to 2024
$13.9M
NIEHS NIH HHS P30 ES000002NIEHS NIH HHS T32 ES007069
6 · The paper itself

Abstract

Given the increased use of air cleaners as a prevention measure in classrooms during the COVID-19 pandemic, this study aimed to investigate the effects of portable air cleaners with HEPA filters and window A/C fans on real-time (1 minute) concentrations of PM less than 2.5 microns (PM2.5) or less than 1 microns (PM1.0) in two classrooms in a non-urban elementary school in Rhode Island. For half of each school day, settings were randomized to "high" or "low" for the air cleaner and "on" or "off" for the fan. Descriptive statistics and linear mixed models were used to evaluate the impacts of each set of conditions on PM2.5 and PM1.0 concentrations. The mean half-day concentrations ranged from 3.4-4.1 μg/m3 for PM2.5 and 3.4-3.9 μg/m3 for PM1.0. On average, use of the fan when the air cleaner was on the low setting decreased PM2.5 by 0.53 μg/m3 [95% CI: -0.64, -0.42] and use of the filter on high (compared to low) when the fan was off decreased PM2.5 by 0.10 μg/m3 [95% CI: -0.20, 0.005]. For PM1.0, use of the fan when the air cleaner was on low decreased concentrations by 0.18 μg/m3 [95% CI: -0.36, -0.01] and use of the filter on high (compared to low) when the fan was off decreased concentrations by 0.38 μg/m3 [95% CI: -0.55, -0.21]. In general, simultaneous use of the fan and filter on high did not result in additional decreases in PM concentrations compared to the simple addition of each appliance's individual effect estimates. Our study suggests that concurrent or separate use of an A/C fan and air cleaner in non-urban classrooms with low background PM may reduce classroom PM concentrations.

Indexed as

COVID-19Household ArticlesHumansPandemicsParticulate MatterSchoolsParticulate Matter

Identifiers

PMID36454721
PMCPMC9714748
OpenAlexW4311069823

What OpenQuestion holds

Textmetadata
LicenceCC0
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.