Understanding the Impact of Cartridge-Based Electronic Cigarettes and Generated Aerosols on Cardiopulmonary Health

Inclusion Criteria: E-Cigarette group: * 21 years of age or older * Used e-cigarettes (≥3 times/week for ≥3 months) Non e-cigarette group ● 21 years of age or older Exclusion Criteria: * 20 years old and younger * Use of cigarettes for 15 days or more in the past 60 days * Use of other tobacco products (cigars, hookah, smokeless) weekly or more frequently in the past 60 days * Use of marijuana or any illicit or prescription drugs for non-medical use weekly or more frequently in the past 60 days * Known allergy to propylene glycol or vegetable glycerin * Evidence of cardiovascular, pulmonary, renal, hepatic, metabolic, or cerebral diseases * Disorder or use of medication that affects cardiopulmonary health * Evidence of pregnancy or current nursing