Impact of Electronic Cigarette Temperature and Solvent on Biomarkers

Subjects will be provided with a study e-cigarette and e-liquid to use during the duration of the study. They will be asked to complete various questionaries as well as provide blood, exhaled breath, exhaled breath condensate, saliva and buccal cell samples.

Their puffing behavior and biomarkers of tobacco exposure and harm will be measured as follows:

E-cigarette (EC) puffing behavior - In order to determine a measurement of toxicant dose, topography markers such as puff duration, number of puffs, and interpuff interval (IPI) will be assessed via video recorded sessions.

E-liquid consumption will be assessed by weighing the filled tanks before and after the session.

Subjective effects such as nicotine withdrawal symptoms, urge to vape, and positive/negative effects will be assessed by questionnaires during the human lab studies.

The total nicotine delivered and GSH oxidation will be calculated in blood via LC-MS. Exhaled breath condensate (EBC) samples will be analyzed by Liquid Chromatography/Mass Spectroscopy (LC/MS) and include the primary biomarker of oxidative stress (8-isoprostane) and a series of proinflammatory cytokines (IL-6 and hsCRP). Exfoliated buccal mucosal cells will be analyzed for 8-OHdG-DNA adducts by LC-MS/MS as a biomarker of oral oxidant exposure/damage.

Inclusion criteria

• 21 years of age or older
• Normal pulmonary and cardiovascular function with no history of COPD or cardiovascular disease (excluding hypertension)
• Current exclusive use of a sub-ohm/mod or pod EC devices (≥ 1mL e-liquid/per day, ≥6 mg/ml nicotine concentration, EC for ≥ 1 year)
• No plan on quitting nicotine use over the course of the study
• All other forms of nicotine must be used <5 days out of the past 28 days.
• Able to read and write in English
• Have access to email and a smartphone/computer that has reliable internet connection

Exclusion criteria

• Women who are pregnant and/or nursing or trying to become pregnant
• Unstable or significant medical condition in the past 3 months (e.g., recent heart attack or other serious heart condition, stroke, severe angina)
• Respiratory diseases (e.g., exacerbations of asthma or COPD, require oxygen, require oral prednisone), kidney (e.g., dialysis) or liver disease (e.g., cirrhosis), severe immune system disorders (e.g., uncontrolled HIV/AIDS, multiple sclerosis symptoms) or any medical disorder/medication that may affect participant safety or biomarker data
• Uncontrolled substance abuse or inpatient treatment for that condition in the past 6 months
• Have immediate family or household members currently participating in this trial