The Impact of Waterpipe Tobacco Flavors on Waterpipe Smoking Intentions, Perceptions, Patterns, and Toxicant Exposure

The overall aim of the current study is to determine if flavorings contribute to the initiation and maintenance of waterpipe (WP) smoking and also influence how a WP is smoked, which has implications for both risk of dependence but also smokers' level of exposure to tobacco-related toxicants. A total of 94 current WP smokers (47 low dependent, 47 high dependent) will be recruited. Based on our team's previous studies we conservatively assume a 20% attrition rate; thus, we will need to recruit 94 participants to have 76 complete all four sessions. Consistent with other laboratory studies of waterpipe smoking, participants who meet the following eligibility criteria will be asked to take part in the study.

After completing the initial screening by phone, participants will be informed of the study procedures and invited to the lab to complete three WP smoking sessions. Participants will perform exhaled carbon monoxide testing (eCO\< 10ppm) and confirm that they have not used any nicotine/tobacco/marijuana products over the last 12 hours. Pregnancy exclusion will also be confirmed with a urine test, and pregnancy tests will be completed at each visit throughout the study. Participants will be randomized and complete study procedures in self-selected dyads. The sessions will be counterbalanced and include: 1) smoking preferred flavored-sweetened WP tobacco, 2) smoking unflavored-sweetened WP tobacco, and 3) smoking unflavored-very low sweetened WP tobacco. Participants will complete all three study visits in the laboratory. Pre-session abstinence from tobacco for at least 12 hours will be mandatory for all participants. Abstinence will be confirmed via participant self-report and an exhaled carbon monoxide monitor (\< 20 ppm) for tobacco use. Participant dyads will smoke hookah ad libitum for up to 1 hour. This procedure will be completed for all visits. Participants will also complete a minimum 48-hour washout period between sessions.

Participants will not be allowed to eat, drink or use their phone during the session. Initially, one piece of charcoal will be lit and placed on top of the foil. Our preliminary studies, as well as other WP laboratory trials, indicate that one piece of charcoal will not be sufficient for one WP session; thus, participants will be provided additional pre-weighed pieces to use as they wish. Use of additional charcoal will be recorded. Participants will smoke ad libitum and a WP puff topography device will discretely record smoking behavior throughout the session, including puff duration, number of puffs, puff volume, puff flow rate, and time between puffs. Blood samples (15mL per sample) and eCO will be collected immediately pre- and post-waterpipe session. Self-report measures will be administered.

Eligibility Criteria:
Inclusion Criteria:

* current water pipe smoker for at least the past 6 months
* smoke water pipe at least 3 times in the last 6 months
* Lebanese Waterpipe Dependence Scale-11 (LWDS-11) score of ≤9 (Low Dependence) or ≥10 (High Dependence)
* between 18-50 years old
* willing to provide informed consent
* abstain from all tobacco, nicotine, and marijuana use for at least 12 hours prior to each of the three sessions

Exclusion Criteria:

* self-reported diagnosis of lung disease including asthma, cystic fibrosis, or chronic obstructive pulmonary disease
* currently pregnant, planning to become pregnant, or breastfeeding
* history of cardiac event or distress within the last 3 months
* any use of other illicit drugs during the last 30 days.