Association of meteorological factors and air NO 2 and O 3 concentrations with acute exacerbation of elderly chronic obstructive pulmonary disease

We studied the combined effect of air pollutant concentrations and meteorological factors [e.g., temperature and atmospheric pressure (AP)] on the acute exacerbation of coronary obstructive pulmonary disease (COPD) in 277 older patients with COPD (240 men and 37 women; average age, 75.3 ± 9.3 years). Average air pollutant concentrations, AP, temperature, and relative humidity corresponding to each of the 7 days before the date of hospitalisation were identified as the case and the two other weekly averages, 4 and 8 weeks prior to admission, were considered the controls. During the warming-up season, COPD exacerbation more likely occurred on days of temperature increase or AP decrease than on other days. Increments in CO, NO 2 and O 3 concentrations were significantly associated with 5%, 11% and 4% increases in COPD exacerbation risks, respectively. During the cooling-down season, increments in PM 10 concentrations were significant risk factors; the exacerbation likely occurred on days of temperature decreases than on other days. Air pollution with increased NO 2 , CO, O 3 and PM 10 concentrations and continual temperature changes (colder during cooling-down seasons or hotter during warning-up seasons) were associated with acute exacerbation of COPD in older patients.