Actual use puffing topography and mouth level exposure to aerosol and nicotine for an evolving series of electronic nicotine delivery systems

Abstract

<p>Electronic nicotine delivery systems (ENDS) have evolved substantially in the past 10 years from disposable “cig-a-likes” to rechargeable devices with refillable tanks or disposable cartridges. It is less clear whether users’ puffing behaviour and exposure to aerosol emissions has similarly altered. Here we evaluate changes in the puffing topography and mouth level exposure (MLE) of users to aerosol and nicotine for a series of commercially available ENDS. In five separate consumer studies conducted from 2014 to 2019, eight Vuse ENDS including cig-a-likes, tanks, pen- and pod-style e-cigarettes were evaluated among ENDS users (total n=221) for puff duration, puff volume, inter-puff interval and MLE to aerosol and nicotine. Puff volumes varied two-fold (35.7-84.8 ml) with the lowest volumes for early ENDS and highest volumes for more recent pod style and tank systems. The variation in puff duration across the devices was smaller (1.70-2.39 s), especially for the five most recent devices (2.13-2.39 s). MLE to aerosol (1.9-6.4 mg/puff) tended to increase with evolution of the ENDS. MLE to nicotine, which depends on the nicotine concentration of the e-liquid as well as device design, was also highest for more recent devices. These data indicate that evolving device characteristics, such as more powerful batteries and aerosolisation technology, influence user puffing topography and the values obtained from one product might not apply to others. Continuing to evaluate ENDS consumer behaviour is important to understand further the factors that affect users’ puffing topography and nicotine uptake from these products.</p>