Cardiorespiratory responses of air filtration: A randomized crossover intervention trial in seniors living in Beijing

Publication date: 15 December 2017
Source:Science of The Total Environment, Volumes 603–604
Author(s): Danqing Shao, Yipeng Du, Shuo Liu, Bert Brunekreef, Kees Meliefste, Qian Zhao, Jie Chen, Xiaoming Song, Meng Wang, Juan Wang, Hongbing Xu, Rongshan Wu, Tong Wang, Baihuan Feng, Candice Shih-Chun Lung, Xian Wang, Bei He, Wei Huang
In this Beijing Indoor Air Purifier StudY (BIAPSY), we conducted a randomized crossover intervention trial in a panel of 35 non-smoking senior participants with free-living, with and without chronic obstructive pulmonary disease (COPD). Portable air filtration units were randomly allocated to active-(filter in) for 2weeks and sham-mode (filter out) for 2weeks in the households. We examined the differences in indoor air pollutant concentrations in 20 study homes and a suite of cardio-respiratory biomarker levels in study participants between filtration modes, with and without adjustment for potential confounders. Following active filtration, we observed significant reductions from 60±45 to 24±15μg/m³ in ten-day averages of indoor PM2.5 and reductions from 3.87±1.65 to 1.81±1.19m⁻¹.10⁻⁵ in ten-day averages of indoor BC, compared to sham-mode filtration. The major components of indoor PM2.5, including water soluble organics, NO3⁻, SO4²⁻, Zn²⁺, Pb²⁺ and K⁺, were also reduced significantly by 42% to 63%. However, following active filtration, we only observed significant reductions on systemic inflammation measured as of IL-8 at 58.59% (95% CI: −76.31, −27.64) in the total group of participants and 70.04% (95% CI: −83.05, −47.05) in the subset of COPD patients, with adjustments. We were not able to detect improvements on lung function, blood pressure, and heart rate variability, following short-term intervention of two-week active air filtration. In conclusion, our results showed that indoor air filtration produced clear improvement on indoor air quality, but no demonstrable changes in the cardio-respiratory outcomes of study interest observed in the seniors living with real-world air pollution exposures.

Graphical abstract

http://ift.tt/2sRuJ9y