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    Original Investigation
    October 2018

    Effect of Portable Air Filtration Systems on Personal Exposure to Fine Particulate Matter and Blood Pressure Among Residents in a Low-Income Senior Facility: A Randomized Clinical Trial

    Author Affiliations
    • 1Department of Family Medicine, College of Human Medicine, Michigan State University, East Lansing
    • 2School of Public Health, University of Michigan, Ann Arbor
    • 3Community Health Nursing, Ann Arbor, Michigan
    • 4Division of Cardiovascular Medicine, University of Michigan, Ann Arbor
    JAMA Intern Med. 2018;178(10):1350-1357. doi:10.1001/jamainternmed.2018.3308
    Key Points

    Question  Can portable air filtration systems reduce personal exposures to fine particulate matter air pollution and blood pressure levels among elderly adults living in a typical US urban location?

    Findings  In this randomized, double-blind crossover intervention study, short-term use of portable air filtration systems reduced personal exposures to fine particulate matter and systolic blood pressure in senior citizens living in a low-income residence.

    Meaning  The use of portable air filtration systems is potentially cardioprotective against exposures to fine particulate matter and warrants further research.


    Importance  Fine particulate matter (smaller than 2.5 μm) (PM2.5) air pollution is a major global risk factor for cardiovascular (CV) morbidity and mortality. Few studies have tested the benefits of portable air filtration systems in urban settings in the United States.

    Objective  To investigate the effectiveness of air filtration at reducing personal exposures to PM2.5 and mitigating related CV health effects among older adults in a typical US urban location.

    Design, Setting, and Participants  This randomized, double-blind crossover intervention study was conducted from October 21, 2014, through November 4, 2016, in a low-income senior residential building in Detroit, Michigan. Forty nonsmoking older adults were enrolled, with daily CV health outcome and PM2.5 exposure measurements.

    Interventions  Participants were exposed to the following three 3-day scenarios separated by 1-week washout periods: unfiltered air (sham filtration), low-efficiency (LE) high-efficiency particulate arrestance (HEPA)–type filtered air, and high-efficiency (HE) true-HEPA filtered air using filtration systems in their bedroom and living room.

    Main Outcomes and Measures  The primary outcome was brachial blood pressure (BP). Secondary outcomes included aortic hemodynamics, pulse-wave velocity, and heart rate variability. Exposures to PM2.5 were measured in the participants’ residences and by personal monitoring.

    Results  The 40 participants had a mean (SD) age of 67 (8) years (62% men). Personal PM2.5 exposures were significantly reduced by air filtration from a mean (SD) of 15.5 (10.9) μg/m3 with sham filtration to 10.9 (7.4) μg/m3 with LE fitration and 7.4 (3.3) μg/m3 with HE filtration. Compared with sham filtration, any filtration for 3 days decreased brachial systolic and diastolic BP by 3.2 mm Hg (95% CI, −6.1 to −0.2 mm Hg) and 1.5 mm Hg (95% CI, −3.3 to 0.2 mm Hg), respectively. A continuous decrease occurred in systolic and diastolic BP during the 3-day period of LE filtration, with a mean of 3.4 mm Hg (95% CI, −6.8 to −0.1 mm Hg) and 2.2 mm Hg (95% CI, −4.2 to −0.3 mm Hg), respectively. For HE filtration, systolic and diastolic BP decreased by 2.9 mm Hg (95% CI, −6.2 to 0.5 mm Hg) and 0.8 mm Hg (95% CI, −2.8 to 1.2 mm Hg), respectively. Most secondary outcomes were not significantly improved.

    Conclusions and Relevance  Results of this study showed that short-term use of portable air filtration systems reduced personal PM2.5 exposures and systolic BP among older adults living in a typical US urban location. The use of these relatively inexpensive systems is potentially cardioprotective against PM2.5 exposures and warrants further research.

    Trial Registration  ClinicalTrials.gov identifier: NCT03334565