IMPACT OF AIR QUALITY INDEX (AQI) ON PULMONARY FUNCTION: AN 18 MONTHS CROSS-SECTIONAL STUDY ON INDIAN POPULATION

Abstract

Introduction: Ambient air pollution always remains a major threat to public health in India, contributing to a large number of deaths annually, particularly due to respiratory and cardiovascular disorders. Despite growing concerns about air quality and respiratory illness, population-based evidence linking Air Quality Index (AQI) levels with pulmonary function in the Indian context remains sparse. This study aimed to evaluate the impact of ambient air quality on pulmonary function across diverse regions of India over an 18-month period.

Materials & Methods: A multi-centric, cross-sectional study was conducted between September 1, 2023, and February 28, 2025. The study recruited 6,000 individuals across urban, semi-urban, and rural locations from 10 Indian states. Daily AQI data was retrieved from the Central Pollution Control Board (CPCB). Spirometry was conducted in accordance with ATS/ERS guidelines. Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV₁), and FEV₁/FVC ratio were analyzed.

Results: A significant inverse correlation was observed between AQI levels and all pulmonary parameters (p < 0.001). Participants residing in areas with consistently good AQI (< 50) had a mean FEV₁ of 3.1 ± 0.4 L, compared to 2.4 ± 0.6 L in those from severely polluted zones (AQI > 300). Children and the elderly showed the most pronounced lung function impairments in poor AQI zones.

Conclusion: This study confirms that poor air quality is strongly associated with impaired lung function across all age groups in the Indian population. Urgent public health interventions, stricter enforcement of the National Clean Air Programme (NCAP), and region-specific pollution control strategies are essential.