Objectives Air pollution is a growing concern in Korea because of transboundary air pollution from mainland China. A panel study was conducted to clarify the effects of air pollution on respiratory symptoms and health-related quality of life (HR-QoL) in outpatients with and without chronic obstructive pulmonary disease (COPD) in Korea. Methods Patients filled out a questionnaire inclu... https://cuttingedgecutleryco.shop/product-category/collections/