Household and occupational air pollution, and demographic drivers of COPD: a hospital-based cross-sectional study in a high-pollution urban setting

Rapid urbanization and severe air pollution levels have increased the burden of chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD). The present hospital-based cross-sectional study investigates demographic, behavioural, and environmental (household and occupational) determinants of COPD among 501 individuals visiting the respiratory outpatient department in Delhi, India. A structured questionnaire was used to collect data capturing socio-demographic, clinical, occupational, and household pollution-related variables, and these were analysed using univariate and multivariate logistic regression. COPD prevalence was 34.1%, with higher occurrence among older individuals (mean age 62.16 years vs. 50.0 years), males, ex-smokers, and those with lower Body Mass Index (BMI). The final multivariate model identified age (AOR = 1.08/year), male gender (AOR = 2.68), smoking status (never smoker: AOR = 0.05; passive smoker: AOR = 0.04), and BMI (AOR = 0.93/unit) as significant independent predictors. Household air pollution variables, such as polluting fuels for water heating like wooden stoves and poor kitchen ventilation, also showed higher odds of COPD prevalence. Occupational exposure further increased the COPD risk, highlighting the need for targeted interventions in high-risk workplace environments. The findings underscore that while traditional determinants such as smoking, age, and BMI are dominant predictors for COPD prevalence in this cohort, household and occupational pollution variables remain critical modifiers of respiratory risk. In areas with very high background pollution and high clean fuel adoption, interventions for indoor settings must prioritize structural household factors that improve kitchen ventilation and design, alongside smoking cessation, occupational safety, and targeted support for vulnerable subgroups to curb the respiratory health crisis in Delhi and similar megacities.