Cardiopulmonary effects of overnight indoor air filtration in healthy non-smoking adults: A double-blind randomized crossover study. (May 2018)

• Record Type: Journal Article
• Authors: Cui, Xiaoxing; Li, Feng; Xiang, Jianbang; Fang, Lin; Chung, Ming Kei; Day, Drew B.; Mo, Jinhan; Weschler, Charles J.; Gong, Jicheng; He, Linchen; Zhu, Dong; Lu, Chengjian; Han, Hailong; Zhang, Yinping; Zhang, Junfeng (Jim)
• Is Part Of: Environment international. Volume 114(2018)
• Page Start: 27
• Page End: 36
• Publication Date: 2018-05
• Subjects: AI Augmentation index -- dBP Diastolic blood pressure -- FeNO Fractional exhaled nitric oxide -- FEV1 Forced expiratory volume during the first second -- Fres Resonant frequency -- FVC Forced vital capacity -- HEPA filter High efficiency particulate air filter -- HR Heart rate -- IL-6 Interleukin-6 -- MDA Malondialdehyde -- PM2.5 Particles with aerodynamic diameters less than or equal to 2.5 μm -- PP Pulse pressure -- PWV Pulse wave velocity -- R5 Airway resistance at 5 Hz -- R5-R20 Airway resistance at 5 Hz minus airway resistance at 20 Hz -- sBP Systolic blood pressure -- sCD62P Soluble P-selectin -- SEVR Subendocardial viability ratio -- SG Specific gravity -- URI Upper respiratory tract infection -- VWF von Willebrand factor -- X5 Airway reactance at 5 Hz, indicator of distal capacitive reactance -- Z5 Airway impedance at 5 Hz, indicating the magnitude of respiratory impedance; Air pollution -- Indoor air quality -- Air filtration -- Airway mechanics -- Thrombosis -- Impulse oscillometry; Environmental protection -- Periodicals; Environmental health -- Periodicals; Environmental monitoring -- Periodicals; Environmental Monitoring -- Periodicals; Environnement -- Protection -- Périodiques; Hygiène du milieu -- Périodiques; Environnement -- Surveillance -- Périodiques; Environmental health; Environmental monitoring; Environmental protection; Periodicals; 333.705
• DOI: 10.1016/j.envint.2018.02.010
• Languages: English
• ISSNs: 0160-4120

Abstract

Abstract: Background: More than 90% of the world's population lives in areas where outdoor air pollution levels exceed health-based limits. In these areas, individuals may use indoor air filtration, often on a sporadic basis, in their residences to reduce exposure to respirable particles (PM2.5 ). Whether this intervention can lead to improvements in health outcomes has not been evaluated. Methods: Seventy non-smoking healthy adults, aged 19 to 26 years, received both true and sham indoor air filtration in a double-blinded randomized crossover study. Each filtration session was approximately 13 h long. True and sham filtration sessions were separated by a two-week washout interval. The study was carried out in a suburb of Shanghai. Results: During the study period, outdoor PM2.5 concentrations ranged from 18.6 to 106.9 μg/m 3, which overlapped with levels measured in Western Europe and North America. Compared to sham filtration, true filtration on average decreased indoor PM2.5 concentration by 72.4% to 10.0 μg/m 3 and particle number concentration by 59.2% to 2316/cm 3 . For lung function measured immediately after the end of filtration, true filtration significantly lowered airway impedance at 5 Hz (Z5 ) by 7.1% [95% CI: 2.4%, 11.9%], airway resistance at 5 Hz (R5 ) by 7.4% [95% CI: 2.4%, 12.5%], and small airway resistance (R5 -R20 ) by 20.3% [95% CI: 0.1%, 40.5%], reflecting improved airway mechanics especially for the small airways. However, no significant improvements for spirometry indicators (FEV1, FVC) were observed. True filtration also significantly lowered von Willebrand factor (VWF) by 26.9% [95% CI: 7.3%, 46.4%] 24 h after the end of filtration, indicating reduced risk for thrombosis. Stratified analysis in male and female participants showed that true filtration significantly decreased pulse pressure by 3.3% [95% CI: 0.8%, 7.4%] in females, and significantly reduced VWF by 42.4% [95% CI: 17.4%, 67.4%] and interleukin-6 by 22.6% [95% CI: 0.4%, 44.9%] in males. Effect modification analyses indicated that filtration effects in male and female participants were not significantly different. Conclusion: A single overnight residential air filtration, capable of reducing indoor particle concentrations substantially, can lead to improved airway mechanics and reduced thrombosis risk. Highlights: Air filtration reduced indoor PM2·5 by 72.4% and particle number concentrations by 59.2%. An overnight filtration improved airway mechanics but not spirometric lung function. It also reduced levels of von Willebrand factor, an indicator of thrombosis risk. Impulse oscillometry provided sensitive measurements of airway mechanics.