A two-center, longitudinal assessment of 40 electronic cigarette users and 40 healthy controls at the initial visit and a follow-up visit 12 months later. This study will determine the impact of electronic cigarette use on pulmonary gas exchange capacity and then corroborate the Hyperpolarized Xenon MRI (HXeMRI) results with the cardiopulmonary stress test at the initial visit and a follow-up visit 12 months later.

Electronic cigarettes have been commercialized as a "less harmful" alternative to traditional cigarettes. Electronic cigarettes generate vapor from ingredients containing well-known toxic materials such as carbonyls, tobacco-specific N-nitrosamines, and heavy metals. Nonhuman studies show that Electronic cigarettes cause pulmonary epithelial, endothelial, and vascular dysfunction. Electronic cigarette use has also been associated with cardiac and pulmonary diseases, including severe respiratory failure. Our preliminary studies suggest that we can detect subtle early changes in healthy young e-cigarette users by hyperpolarized xenon-129 MR imaging. We anticipate the following results from the three primary analyses. First, there will be significantly impaired gas exchange in electronic cigarette users compared to healthy controls at the initial and follow-up visits. Second, gas exchange impairment in electronic cigarette users will increase after an additional 12 months of electronic cigarette use. Further, as a secondary analysis, we speculate that because electronic cigarette users exhaust their cardiopulmonary reserve at rest, they will have reduced physical fitness detectable by the 6-minute walk and Cardio-pulmonary exercise tests.

Inclusion Criteria:

1. Ages between 18 and 35 years old.

2. At their baseline health

3. Ability to understand a written informed consent form and comply with the requirements of the study.

4. Exclusive long-term, recent, and greater than six months continuous e-cigarette use with greater than three days a week frequency.

5. Users of "closed-container" and "pre-packaged" electronic cigarette juices that must contain nicotine.

6. Healthy subjects must be at baseline normal spirometry with or without bronchodilator, plethysmograph lung volume, DLCO, and 6-minute walk by ATS/ERS with Global Lung Initiative Reference. (PFT will be completed during a screening visit); Ecigarette users can have normal spirometry (FEV1/FVC>70) or abnormal spirometry (FEV1/FVC 26-70)

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Exclusion Criteria:

1. History of any other lung disease
2. History of brain diseases including stroke (CNS) and dementia, end-stage liver disease, coronary artery disease, renal failure
3. Acute infection of any kind previous 6 weeks
4. Pregnancy or a possibility of pregnancy
5. Anemia
6. Inability to undergo PFT, CPET, or MR imaging (usual clinical standard criteria for MRI)
7. Prior cigarette smoking of greater than one pack-year within six months before enrolling in the study.
8. Using a non-closed container, custom-made electronic cigarette juice, or inability for the study team to access "closed-container" and "pre-packaged" electronic cigarette juice for chemical analysis

As a part of publications.