Morishita M, et al. - In this randomized, double-blind, crossover intervention study, researchers examined the effectiveness of air filtration at reducing personal exposures to fine particulate matter smaller than 2.5 μm (PM_2.5) and attenuating related cardiovascular (CV) health effects among older adults in a typical urban US location (Detroit, Michigan). Findings showed that, among older adults living in a typical US urban location, short-term use of portable air filtration systems reduced personal PM_2.5 exposures and systolic blood pressure (BP) levels. For reducing PM_2.5-related health effects, this relatively inexpensive and practical approach may be an effective tool.

Methods

• This investigation was conducted from October 21, 2014, to November 4, 2016, in a low-income senior residential building in Detroit, Michigan.
• A total of 40 nonsmoking older adults were enrolled, with daily CV health outcome and PM_2.5 exposure measurements.
• Study 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.
• Brachial BP was the primary outcome.
• Aortic hemodynamics, pulse-wave velocity, and heart rate variability were the secondary outcomes.
• Researchers measured exposures to PM_2.5 in the participants’ residences and by personal monitoring.

Results

• According to the findings obtained, the 40 participants had a mean (standard deviation [SD]) age of 67 (8) years and 62% were men.
• It was observed that personal PM_2.5 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 filtration and 7.4 (3.3) μg/m³ with HE filtration.
• Any filtration for 3 days decreased brachial systolic and diastolic BP levels by 3.2 mm Hg (95% confidence interval [CI]: -6.1 to -0.2 mm Hg) and 1.5 mm Hg (95% CI: -3.3 to 0.2 mm Hg), respectively, compared with sham filtration.
• The data presented in this work showed that a continuous decrease occurred in systolic and diastolic BP levels 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.
• Systolic and diastolic BP levels 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, for HE filtration.
• It was noted that most secondary outcomes were not significantly improved.