Conclusion
Among air pollutants, PM10 uniquely affects CE at lag-specific day 5 (from lag day 4 to lag day 6). For the lag-cumulative effect of PM10, CE risk showed a pattern proportional to the concentration of PM10. When we look at how other air pollutants and environmental factors affect each age group differently, we need to devise different strategies for air pollutants and age of COPD patients.