Ambient air pollution and hospitalization for chronic obstructive pulmonary disease: Benefits from Three-Year Action Plan.

Background: Chronic obstructive pulmonary disease (COPD) hospitalization has been linked with ambient air pollution. However, the evidence on respiratory health benefits from air pollution control policy in China is limited.

Objective: To investigate benefits from the Three-Year Action Plan to Win the Battle for a Blue Sky (TYAP) for tackling COPD hospitalization due to ambient air pollution.

Methods: We conducted a time-stratified case-crossover study of 138,015 COPD hospitalizations aged ≥ 60 years in Guangdong province, China during 2016-2019 to investigate respiratory health benefits from TYAP. Inverse distance weighting method was used to assess daily individual-level exposures to ambient air pollutants including particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM), particulate matter with an aerodynamic diameter ≤ 10 µm (PM), sulfur dioxide (SO), nitrogen dioxide (NO), carbon monoxide (CO), and ozone (O). Conditional logistic regression model was applied to analyze the associations between ambient air pollutants and COPD hospitalization.

Results: TYAP can modify the associations. Each 10 μg/m increase of exposure to PM, PM, and NO and 1 mg/m increase of exposure to CO were significantly associated with 2.5%, 2.0%, 3.0%, and 14.4% increase in odds of COPD hospitalization before TYAP, respectively; while 1.0%, 0.9%, 1.5%, and 5.8% increase in odds during TYAP. We found prominent declines in health burden of COPD hospitalizations due to air pollution among the elderly after TYAP implication when compared with that before TYAP.

Conclusion: Reduced levels of ambient air pollutants by TYAP can effectively lower the risk for COPD hospitalization among the elderly, which provides evidence on the respiratory health benefits from consistent and effective air pollution control policy.