Alternate Nicotine Delivery Systems and Airway Epithelial Biology

Subjects have smoked \<100 cigarettes or \<10 shisha pipes per lifetime and whose urine nicotine \<2 ng/mL and/or urine cotinine \<5 ng/mL, at entry into the study.

Defined by self-report and urine nicotine \>30 ng/mL and/or urine cotinine \>50 ng/ml.

Defined by self-report of smoking \>4 pipes/wk and carboxyhemoglobin \>2.5.

Defined by self-report and urine nicotine \>30 ng/ml and/or urine cotinine \>50 ng/ml. Subjects must be a current smoker willing to stop smoking. Subjects will stop smoking after the baseline bronchoscopy, and switch to taking a smoking cessation medication called varenicline. We will provide subjects with the smoking cessation medication as part of this study. They will also receive phone calls to help with smoking cessation counseling.

Defined by self-report and urine nicotine \>30 ng/ml and/or urine cotinine \>50 ng/ml. Must be willing to switch from tobacco cigarettes to electronic cigarettes. The switch will occur after the baseline bronchoscopy. The nicotine dose that will be given to each subject will be determined by the study physician based on the urine smoking metabolite test. It will be adjusted depending on whether the subject is a light smoker or heavy smoker (Light smoker defined as having either a urine nicotine value from 2ng/ml-1000ng/ml or a urine cotinine value from 5ng/ml-1000ng/ml. Heavy smoker is defined as having either a urine nicotine or cotinine value of over 1000ng/ml.) We will provide the subjects with the electronic cigarettes to use as part of this study.