Ambient air pollution, lung function and COPD: cross-sectional analysis from the WHO Study of AGEing and adult health wave 1

BMJ Open Respir Res. 2020 Dec;7(1):e000684. doi: 10.1136/bmjresp-2020-000684.

Abstract

Background: Long-term exposure to ambient air pollution leads to respiratory morbidity and mortality; however, the evidence of the effect on lung function and chronic obstructive pulmonary disease (COPD) in older adult populations is inconsistent.

Objective: To address this knowledge gap, we investigated the associations between particulate matter (PM), nitrogen dioxide (NO2) exposure and lung function, as well as COPD prevalence, in older Chinese adults.

Methods: We used data from the WHO Study on global AGEing and adult health (SAGE) China Wave 1, which includes 111 693 participants from 64 townships in China. A cross-sectional analysis explored the association between satellite-based air pollution exposure estimates (PM with an aerodynamic diameter of ≤10 µm [PM10], ≤2.5 µm [PM2.5] and NO2) and forced expiratory volume in one second (FEV1), forced vital capacity (FVC), the FEV1/FVC ratio and COPD (defined as post-bronchodilator FEV1/FVC <70%). Data on lung function changes were further stratified by COPD status.

Results: Higher exposure to each pollutant was associated with lower lung function. An IQR (26.1 µg/m3) increase in PM2.5 was associated with lower FEV1 (-71.88 mL, 95% CI -92.13 to -51.64) and FEV1/FVC (-2.81 mL, 95% CI -3.37 to -2.25). For NO2, an IQR increment of 26.8 µg/m3 was associated with decreases in FEV1 (-60.12 mL, 95% CI -84.00 to -36.23) and FVC (-32.33 mL, 95% CI -56.35 to -8.32). A 31.2 µg/m3 IQR increase in PM10 was linked to reduced FEV1 (-8.86 mL, 95% CI -5.40 to 23.11) and FEV1/FVC (-1.85 mL, 95% CI -2.24 to -1.46). These associations were stronger for participants with COPD. Also, COPD prevalence was linked to higher levels of PM2.5 (POR 1.35, 95% CI 1.26 to 1.43), PM10 (POR 1.24, 95% CI 1.18 to 1.29) and NO2 (POR 1.04, 95% CI 0.98 to 1.11).

Conclusion: Ambient air pollution was associated with lower lung function, especially in individuals with COPD, and increased COPD prevalence in older Chinese adults.

Keywords: COPD epidemiology; COPD pathology; clinical epidemiology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aged
  • Air Pollutants* / adverse effects
  • Air Pollutants* / analysis
  • Air Pollution* / adverse effects
  • Air Pollution* / analysis
  • Cross-Sectional Studies
  • Environmental Exposure / adverse effects
  • Environmental Exposure / analysis
  • Humans
  • Lung
  • Middle Aged
  • Pulmonary Disease, Chronic Obstructive* / epidemiology
  • Pulmonary Disease, Chronic Obstructive* / etiology
  • World Health Organization

Substances

  • Air Pollutants