Indoor air purifiers good for children’s pulmonary health
12 Dec 2024
Prolonged air purification in indoor environments helps alleviate airway inflammation in children, a study has shown.
The randomized crossover study included 79 school-aged children (mean age 10.3 years, 48 percent male). Each of the children underwent a multisetting (both in classrooms and bedrooms) air purification and a sham purification intervention in a random sequence. Each period lasted for 76 days, with a washout period of 88 days in between.
The primary outcomes included pulmonary function, airway inflammation markers, and metabolites in exhaled breath condensate (EBC). Linear mixed-effects models were used to estimate the respiratory benefits of air purification. Metabolomics was performed to identify differential metabolites in EBC and explore their possible mediation roles.
During the study period, the mean concentration of outdoor fine particulate matter (PM2.5) at the school site was 32.53 μg/m3. Compared with sham, air purification reduced the time-weighted personal PM2.5 concentration by 45.14 percent (mean, 21.49 vs 39.17 μg/m3).
Air purification also yielded improvements in forced expiratory volume in 1 second (8.04 percent, 95 percent confidence interval [CI], 2.15–13.93), peak expiratory flow (16.52 percent, 95 percent CI, 2.76–30.28), forced vital capacity (FVC) (5.73 percent, 95 percent CI, 0.48–10.98), forced expiratory flow at 25% to 75% of FVC (17.22 percent, 95 percent CI, 3.78%-30.67%), maximal expiratory flow at 75% of FVC (14.60 percent, 95 percent CI, 0.35–28.85), maximal expiratory flow at 50% of FVC (17.86 percent, 95 percent CI, 3.65–32.06), and maximal expiratory flow at 25% of FVC (18.22, 95 percent CI, 1.73–34.70).
Fractional exhaled nitric oxide decreased by 22.38 percent (95 percent CI, 2.27–42.48) during the air purification vs the sham purification period.
A number of metabolites in EBC, including L-tyrosine and β-alanine, mediated the effect of air purification on respiratory health.
The findings underscore the importance of intensified indoor air purification in regions with high air pollution levels.