Effect of Ambient Air Pollutants on Acute changes in Pulmonary Variables and Inflammatory Markers in Healthy Adults:...

Air pollution is associated with adverse health effects, particularly on respiratory and cardiovascular systems. Smog, prevalent in Northern India, contains particulate matter (PM10, PM2.5) and gaseous pollutants that can impair pulmonary function. Ambient air pollution can be quantified by the air quality index (AQI). Understanding the acute effects of air quality on respiratory physiology and inflammation is essential.

A pilot prospective longitudinal observational study evaluated healthy volunteers during high (HAQI, AQI >350) and low pollution (LAQI, AQI <150) phases. Spirometry and impulse oscillometry (IOS) assessed lung function; and biomarkers (interleukin-6, tumor necrosis factor alpha) were measured from exhaled breath condensate (EBC) and serum. Paired t-tests or Wilcoxon signed-rank tests were used for analysis.

A total of 21 participants (mean age 25.4±7.4 years, female 33.3%, body mass index 23.9±3.5 kg/m²) completed measurement at both HAQI (395.7±43.8) and LAQI (85.4±9.7). Spirometry revealed significantly lower slow vital capacity (SVC%, 81.6±11.2 vs. 87.7±7.7%, P = 0.008) and forced vital capacity (FVC%, 86.2±9.8 vs. 90.9±9.4%, P = 0.0005) under HAQI compared to LAQI. Forced expiratory volume at 1 second (FEV₁) was also reduced (P < 0.0001), while FEV₁/FVC remained unchanged. IOS showed higher airway resistance (R₅, R₂₀) during HAQI (P < 0.0001). Inflammatory biomarkers in serum and EBC showed no statistical differences between HAQI and LAQI. Despite measurable differences, spirometry and IOS parameters remained within normal limits.

Acute air pollution exposure impairs lung function and increases airway resistance in healthy adults. These findings underscore the need for larger longitudinal studies to clarify the mechanisms linking acute air pollution exposure to chronic health outcomes.