Particulate matter in aerosols produced by two last generation electronic cigarettes: a comparison in a real-world environment.

Introduction:
This article presents a study that compares the aerosol characteristics of two different electronic cigarette (e-cig) models, Just Fog and JUUL, in real-world conditions. The study measures the number of particles (particles/cm3) in the aerosol generated by these e-cigs using an optical particle counter (OPC) model Profiler 212-2. The experiments were conducted with and without a heating, Ventilating air Conditioning System (hVaCS) in operation to evaluate the efficiency of air filtration.

Key Points:

* The study was conducted in a 48 m3 room with a single room hVaCS.
* Two e-cig models, Just Fog and JUUL, were tested in real-world conditions.
* Real-time and time-integrated measurements of the aerosol in particle number (particles/cm3) were taken using an OPC model Profiler 212-2.
* The experiments were conducted with and without hVaCS in operation.
* The OPC recorded significant increases in the number of particles/cm3 during the vaping sessions.
* The JUUL e-cig produced significantly lower emissions than Just Fog with and without the hVaCS in operation.
* The half-life of the e-cig aerosols was in the order of a few seconds, even without the hVaCS in operation.
* The e-cig aerosol generated by the JUUL proved significantly lower than that generated by the Just Fog, but this reduction may not be sufficient to eliminate or consistently reduce the health risk for vulnerable non e-cig users exposed to it.

Main Message:
The study demonstrates the rapid volatility or change from liquid or semi-liquid to gaseous status of the e-cig aerosols, with half-life in the order of a few seconds. The e-cig aerosol generated by the JUUL proved significantly lower than that generated by the Just Fog, but this reduction may not be sufficient to eliminate or consistently reduce the health risk for vulnerable non e-cig users exposed to it. Therefore, it is crucial to regulate the use of e-cigs in public spaces to protect non-users from potential health risks associated with second-hand exposure to e-cig aerosols.

Borgini a, Veronese C, De Marco C, et al. Particulate matter in aerosols produced by two last generation electronic cigarettes: a comparison in a real-world environment. Pulmonology. Published online april 17, 2021. doi:10.1016/j.pulmoe.2021.03.005