Smoking cigarettes has long been proven to cause severe lung damage, including chronic obstructive pulmonary disease (COPD), emphysema, and lung cancer. Over time, cigarette smoke destroys lung tissue, fills airways with tar, The role of cigarette smoke induced pulmonary vascular endothelial cell apoptosis in COPD Respiratory Research Springer Nature Link Health Effects of Cigarettes: Chronic Obstructive Pulmonary Disease (COPD) Smoking and Tobacco Use CDC Marijuana and Your Lungs: Is Vaping Safe for People with COPD? Vaping Related Illness and Lung Disease NEJM