What scientists discovered the cause of the disease of emphysema?

The cause of emphysema was significantly elucidated by researchers in the mid-20th century, particularly by scientists like Dr. Frederick A. McDonald and Dr. John E. C. Cournand. They contributed to the understanding of the disease's link to cigarette smoking and the role of alpha-1 antitrypsin deficiency. Their work helped clarify that emphysema involves the destruction of alveoli in the lungs, primarily due to chronic inflammation and damage from tobacco smoke or genetic factors.