Individual- and Household-Level Interventions to Reduce Air Pollution Exposures and Health Risks: a Review of the Recent Literature

Abstract

Purpose of Review We reviewed recent peer-reviewed literature on three categories of individual- and household-level interventions against air pollution: air purifiers, facemasks, and behavior change. Recent Findings High-efficiency particulate air/arresting (HEPA) filter air purifier use over days to weeks can substantially reduce fine particulate matter (PM2.5) concentrations indoors and improve subclinical cardiopulmonary health. Modeling studies suggest that the population-level benefits of HEPA filter air purification would often exceed costs. Well-fitting N95 and equivalent respirators can reduce PM2.5 exposure, with several randomized crossover studies also reporting improvements in subclinical cardiovascular health. The health benefits of other types of face coverings have not been tested and their effectiveness in reducing exposure is highly variable, depends largely on fit, and is unrelated to cost. Behavior modifications may reduce exposure, but there has been little research on health impacts. Summary There is now substantial evidence that HEPA filter air purifiers reduce indoor PM2.5 concentrations and improve subclinical health indicators. As a result, their use is being recommended by a growing number of government and public health organizations. Several studies have also reported subclinical cardiovascular health benefits from well-fitting respirators, while evidence of health benefits from other types of facemasks and behavior changes remains very limited. In situations when emissions cannot be controlled at the source, such as during forest fires, individual- or household-level interventions may be the primary option. In most cases, however, such interventions should be supplemental to emission reduction efforts that benefit entire communities.

Impact of Wildfire Smoke Events on Indoor Air Quality and Evaluation of a Low-cost Filtration Method

“…However, a low-cost MERV-13 fan filter unit (FFU) achieved a >75% reduction in residential and school PM1 particle mass concentrations indoors relative to ambient smoke haze concentrations (Tham et al, 2020(Tham et al, , 2018. The health/economic benefits of filtration interventions are likely to exceed purchase and operation costs, particularly if targeted to vulnerable populations (Allen and Barn, 2020;Fisk and Chan, 2017).…”

Portable HEPA filter air cleaner use during pregnancy and children’s behavior problem scores: a secondary analysis of the UGAAR randomized controlled trial

“…Portable high efficiency particulate air (HEPA) filter air cleaners (“HEPA cleaners”) reduce indoor PM 2.5 concentrations by 29–82% [ 19 , 20 ]. Because outdoor air pollution infiltrates into buildings, indoor air contains pollution emitted from both outdoor and indoor sources.…”

A review on reducing indoor particulate matter concentrations from personal‐level air filtration intervention under real‐world exposure situations

“…Personal-level air filtration intervention can reduce indoor air pollution of various environmental origins in individual houses and public indoor spaces. [19][20][21] Recently, several reviews have qualitatively evaluated the impact of multiple personal-level interventions against air pollution exposure, [22][23][24] and two meta-analyses assessed the changes in cardiovascular health indicators following indoor air filtration interventions. 25,26 However, the effectiveness of personallevel use of air filtration units in reducing indoor air pollution concentrations under real-world exposure situations has not been quantitatively assessed following systematic review guidelines for intervention studies.…”