Physico-Chemical Properties of Waterpipe Tobacco Smoke and Influential Variables

Waterpipe Tobacco Smoking has become increasingly prevalent globally, especially among youth in part due to the use of flavorants in the shisha, as well as the misconception that it is a safer alternative to cigarette smoking. Previous studies have also found that the presence of flavorants influences smoking topography. Our work focuses on the impact of shisha flavor and smoking topography on the physical and chemical properties of the waterpipe tobacco smoke (WTS) produced. WTS is generated using a laboratory smoking apparatus and topographies that vary in puff length, interpuff interval, and flow rate. Particle size and concentration are measured using a TSI Engine Exhaust Particle Sizer. For a constant session length, the total particle concentration in WTS has a dependence on smoking topography but not flavor, with longer puffs and shorter IPIs demonstrating higher concentrations. Normalizing to account for differences in total smoke volume between topographies resulted in minimal differences in particle concentration. Particle size distributions do vary with flavor and topography. Particulates are collected on quartz fiber filters and extracted using SPE. Gas phase compounds are collected on Empore SPE discs. Chemical composition is characterized using a Bruker GCMS. Flavor differentiating compounds are further quantified. The addition of flavorants show an increase in the number of compounds as compared to the unflavored control for all topographies. Mass balance of flavor differentiating compounds demonstrate some filtering by water in the bowl as a function of shisha concentration or amount produced during the smoking process. The physical and chemical properties of WTS generated under one topography with one flavor are not representative of other topographies or flavors. Flavorants that increase the appeal of WTS also alter the particle size distribution and chemical composition of the smoke, which could correlate to higher health risks.