The second group will be recruited as a control group consisting of healthy adult participants through purposive convenience sampling at other collaborating UAB sites. The principal investigator will collect self-report responses through a questionnaire packet given to anyone willing to participate in the study

12 questions adopted from Gideon et al. (2016) will be used to discover which participants believe that they suffer from eating disorders. This measure showed high internal consistency (Cronbach's α = .913) and temporal stability (ICC = .93; p < .001) (continuous variable). These range from a score of zero ("no symptoms") to three ("extreme symptoms").

A short form of the e-cigarette consequence questionnaire will be used to assess the e-cigarette expectancy questionnaire. This questionnaire was developed and validated by Peter S. Hendricks et al. (2014). Cronbach's alpha reliabilities of the e-cigarette-specific range from .67 to .88 (ordinal variable). This questionnaire has 25 statements. Each statement contains a possible consequence of smoking an e-cigarette. For each of the statements, participants should rate how LIKELY or UNLIKELY that they believe each consequence is for them when they use an e-cigarette. If the consequence seems LIKELY to them, they should circle a number from 5-9. That is, if they believe that a consequence would never happen, circle 0; if they believe a consequence would happen every time they smoke, circle 9. If it seems a little unlikely to them, they would circle 4

Questions that have been successfully used in previous studies (Adkison et al., 2013; Choi & Forster, 2013; Nicksic et al., 2017; Stein et al., 2015) will be used to assess the participants' risk perception of e-cigarettes (ordinal variable). There are six statements that assess the participants' perception toward e-cigarette, and the participants should choose between 1 to 5 where 1 means "strongly disagree" and 5 means "strongly agree".

The Comparing E-cigarettes and Cigarettes Questionnaire (CEAC) will be used to assess attitudes towards e-cigarettes compared to cigarettes. The CEAC is a 17-item self-report measure with three factors: (1) General Benefits (seven items; α = 0.85), (2) Addiction/Cessation Benefits (five items; α = 0.89), and (3) Improve Health (five items; α = 0.92) (Hershberger, Karyadi, VanderVeen, & Cyders, 2017). The CEAC has been shown to be positively related to e-cig use (b 0.41-1.24, p < .01) and has demonstrated good psychometric properties (α 0.83-0.93) (ordinal variable). There are ten statements that assess the participants' perception toward e-cigarette, and the participants should choose between 1 to 5 where 1 means "strongly disagree" and 5 means "strongly agree".

A scale of 1 to 10 has been used before by Peter S. Hendricks et al. (2014) will be used to assess the desire to quit smoking and the success of quitting among smokers (continuous variable). (Scale of 1 to 10 with 1 = No desire to quit and 10 = full desire to quit).

They will be assessed using a previously used questionnaire (P. S. Hendricks, Delucchi, Humfleet, & Hall, 2012) (categorical variable). Participants should choose "Yes" or "No" based to see if they drink alcohol or use any of the addictive substance.

To assess different areas related to some environmental factors, the following questions will be asked: "When you are using the Internet, how often do you see ads or promotions for e-cigarettes," "When you read newspapers or magazines, how often do you see ads or promotions for e-cigarettes," "When you go to a convenience store, supermarket, or gas station, how often do you see ads or promotions for e-cigarettes," and "When you watch TV, how often do you see ads or promotions for e-cigarettes." Participants can choose from a Likert scale with responses range from 1 to 6 where 1 means ("No use/watch/see/go") and 6 means "always". This question has been successfully used in previous Centers for Disease Control and Prevention (CDC) studies (ordinal variable).

To assess awareness of warning labels on e-cigarettes and associated paraphernalia, we will use the following question: "During the past 30 days, how often did you see a warning label on an e-cigarette package?" Participants can choose from 6 Likert scale categories in order for them to answer the preceding questions. 1 indicates "I did not see an e-cigarette package during the past 30 days" and 6 indicates always. This question has been successfully used in previous Centers for Disease Control and Prevention (CDC) studies (ordinal variable).

Exposure to special price offers for e-cigarettes will be assessed by asking: "In the last 30 days, have you noticed any special price offers, such as discounts or coupons, for e-cigarettes/vaping devices or e-liquid?" Response options include "Yes" and "No". This question has been successfully used in previous Centers for Disease Control and Prevention (CDC) studies (categorical variable).

A question will be asked regarding number of days that someone breathes vapor from someone who was using an e-cigarette in an indoor or outdoor public place. This question has been successfully used in previous Centers for Disease Control and Prevention (CDC) studies (continuous variable).

The following question will be asked regarding using e-cigarettes in home "Does anyone who lives with you use e-cigarette?" (yes/no). This question has been successfully used in previous Centers for Disease Control and Prevention (CDC) studies (categorical variable).

A question will be asked to see if e-cigarette use was suggested by a healthcare provider. This question has been successfully used by Harrington et al. (2014) in previous studies (yes/no) (categorical variable).

The questionnaire that will be used in our study was adopted from a study performed by Nicksic, Snell, Rudy, Cobb and Barnes (44). Nicksic, Snell, Rudy, Cobb and Barnes (44) adapted a validated measure on susceptibility to smoking. The adapted survey scale for measuring susceptibility to using e-cigarette showed a high degree of internal consistency (Cronbach's alpha = 0.97). The susceptibility to e-cigarette use score is constructed based on participants' responses to the following questions: (1) Do you think that you will use an e- cigarette soon? (2) Do you think that in the future you might experiment with e-cigarettes? (3) Do you think you will use an e-cigarette in the next year? and (4) If one of your best friends were to offer you an e-cigarette, would you smoke it? After each question, participants could endorse "Definitely not," "Probably not," "Probably yes," and "Definitely yes." (Continuous variables).

The Penn State Cigarette Dependence Index (PS-CDI) to assess cigarette dependence. The PS-CDI (α = .72) both have fair to good internal consistency (Foulds et al., 2015). The PS-CDI also appears to be a valid measure of the dependence construct, capturing self-perceived addiction, heavy use, early use after overnight deprivation, and continued use over time (continuous variable). The Penn State Cigarette Dependence Index (PS-CDI) to assess cigarette dependence. The PS-CDI (α = .72) both have fair to good internal consistency (Foulds et al., 2015). The PS-CDI also appears to be a valid measure of the dependence construct, capturing self-perceived addiction, heavy use, early use after overnight deprivation, and continued use over time (continuous variable). Scoring: 0-3= not dependent, 4-8 low dependence, 9-12 medium dependence, 13+ = high dependence

ICD-10-CM (International Classification of pulmonary diseases) will be used to determine if the healthy adults have a history of pulmonary disease.