In the 30 years since its introduction, sweetened waterpipe (WP) tobacco, or ?ma?assel?, is now smoked by over half a million middle and high school children and 1.2M young adults in the U.S. This may be due to the sweet additives that comprise up to 70% of the weight of the tobacco and make inhaling WP tobacco smoke more appealing and easier for first-time users. WP tobacco is unique in that the ratio of sweet additives to nicotine is significantly higher than for any other tobacco product, making WP the perfect ?starter product? for nicotine initiation. It is largely misperceived that smoking tobacco with a WP or hookah is a less harmful form of tobacco use. In fact, the high levels of sweet additives transfer nicotine efficiently and produce harmful and potentially harmful constituents in the smoke, contributing to the direct and indirect harm experienced by users. To define the effects of WP tobacco?s primary chemical additives with respect to sweet perception, appeal, toxicant exposure, addictiveness, harm and health risk perceptions, and lung function among WP users, WP tobacco that differs only in the additives of interest must be used. There is no set of commercially available tobacco brands for which this is true, and thus our study will manipulate commercial products to properly isolate the important variables. There is an existing data gap surrounding the influence of WP tobacco?s primary additives, all of which are sweet tasting compounds, on the addictiveness, toxicity, flavor perceptions, appeal and perceived harm of WP smoking. The proposed study uses a crossover single-blind human trial of dyads, a manipulated WP tobacco product, a validated dual-hose research-grade WP, cutting edge psychosocial instruments and analytical chemistry techniques to assess human exposure to systematically investigate the effects of sweet additives on the appeal, puffing behavior, and toxicity of WP tobacco smoking. Currently there are no regulations governing WP additives. The purpose of the proposed study is to acquire sound scientific data to inform the development of evidenced-based product standards, or limits to additives in WP tobacco that must not be exceeded in order for the product to be sold and distributed in the U.S. The proposed study will address RFA-OD-19-028?s Scientific Interest Areas of: Chemistry and Engineering, Toxicity, and Behavior and Addiction, in that it will determine how specific WP tobacco additives affect users puffing behavior, liking, harm perceptions, the quantities of toxicants they inhale and take up in the body, and acute pulmonary affects from WP tobacco smoking.
Sweet additives make up the bulk waterpipe tobacco and have the potential to contribute to indirect harm by increasing the amount of smoke inhaled, and direct harm by degrading to form harmful and potentially harmful constituents (HPHCs) that are subsequently inhaled by the smoker. The objective of this human study is to individually quantify the harm associated with medium and high levels of the primary waterpipe tobacco additives.