Comparative assessment of the side-stream aerosols emitted from heat-not-burn tobacco devices, e-cigarettes and traditional cigarettes

Consumption of e-cigarettes has increased significantly in recent years, necessitating further research on the potential health risks/benefits of these devices. Recently, Philip Morris International entered the e-cigarette market with the launch of “iQOS”, a “heat-not-burn” cigarette that has been described as a hybrid between traditional and electronic cigarettes. In a recent study (Saffari et al. 2014, Environ. Sci. Process Impacts, 2259-2267), we presented exposure to particulate metals and organic compounds from e-cigarettes. In this study, we have used a similar approach to further expand our previous analyses by characterizing the iQOS. Black carbon (BC) in addition to particle mass and number concentration were measured using continuous monitors, inside of an office environment during e-cigarette and iQOS consumption sessions. Additionally, particle-bound metals and organic compounds as well as gas-phase aldehydes were quantified using time-integrated chemical analysis methods. Moreover, indoor emission rate of these chemical species were quantified by conducting parallel outdoor measurements followed by development of an indoor mass balance model. Our results indicated a substantial decrease in the emission of metals (with the exception of Ni and Cr), BC and organic compounds in e-cigarettes compared to traditional cigarettes. Analysis of the same species in the iQOS side-stream smoke, however, indicated that while PAHs were mostly non-detected in the iQOS smoke, certain n-alkanes, organic acids were still emitted in substantial levels from iQOS.