# Effect of portable air filtration systems among female residents of old age home in northern India with hazardous air quality

## TL;DR

Portable air filtration systems improved cardiovascular and inflammatory health in elderly women during a period of severe air pollution in northern India.

## Contribution

Portable air filtration systems can reduce cardiovascular and oxidative stress in elderly women during hazardous air quality.

## Key findings

- AFS reduced indoor PM2.5 levels from hazardous to significantly lower levels.
- AFS led to a significant decrease in systolic blood pressure and inflammatory markers like CRP and 8-oxo-DG.
- Pulse wave velocity also decreased during AFS use but returned to baseline after sham AFS.

## Abstract

Air pollution is among leading contributors toward cardiovascular diseases. This study evaluated the impact of air filtration systems (AFS) on cardiovascular and oxidative health during severe (hazardous category) pollution season. It was a single‐arm crossover single‐center study conducted at an all‐female old age home. Portable AFS with HEPA (high‐efficiency particulate air) filters were used for 2 weeks during the intervention phase followed by sham AFS for another 2 weeks (single‐blinded). Primary outcome was change in systolic blood pressure (at baseline, after AFS and after sham AFS). Other outcomes include, change in pulse wave velocity, CRP (C‐reactive protein) levels, and 8‐Oxo‐2′‐deoxyguanosine (8‐oxo‐DG). Final analysis included data from 29 subjects with mean age 65.83 ± 6.4 years. At baseline, PM2.5 levels were in hazardous category (PM2.5: 440.38 ± 44.3 μg/m3). With AFS, indoor PM2.5 levels came down (131.0 ± 19.2 μg/m3). After sham AFS, the levels rose back to the baseline (PM2.5: 414.2 ± 32.2 μg/m3). Primary outcome measurement revealed a drop in both systolic (p < 0.001) and diastolic blood pressure (p = 0.14) after installation of AFS. Both CRP and 8‐oxo‐DG followed a similar trend (p < 0.001). Average pulse wave velocity (from 10 subjects) also decreased after AFS but rose back to baseline value after sham AFS (both p < 0.001). Findings of this study showed that AFS though failed to normalize the quality of air but had a positive impact on cardiovascular and inflammatory parameters.