Summary
Introduction:
This article presents a study that compares the aerosol emissions of electronic cigarettes (e-cigs) and conventional cigarettes in real-time. The study measures the mass and number concentration along with the number size distributions of the aerosols produced by vaping various e-cig liquids and smoking conventional cigarettes in a closed room.
Key Points:
* E-cigs initially produced higher particle mass and number concentrations compared to conventional cigarettes.
* however, e-cig emissions had a much shorter lifetime of approximately 10-20 seconds, while conventional cigarette particles remained in the particle phase and were homogeneously distributed in the room within 0.1 hour.
* E-cig aerosols consisted almost only of propylene glycol and/or vegetable glycerin, which evaporated rapidly.
* The concentration of the exhaled e-cig aerosol tends to decrease rapidly when diluted in environmental air.
* E-cig aerosol size ranges widely, and it can either have bimodal or monomodal particle size distribution.
* The majority (~85%) of conventional cigarette smoke arises from side stream emissions generated during static cigarette smolder between puffs, which is absent in e-cigs.
* The experiments took place in a specially designed laboratory room with an area of ~12 m2 and a volume of 35 m3 for the real-time measurement of the generated suspended particles.
* a scanning mobility particle sizer (SMPS), a di erential mobility analyzer (DMa), a condensation particle counter (CPC), and a DustTrak were used to measure the aerosol size distribution, mass concentration, and number concentration.
Main Message:
The study found that e-cigs emit aerosols which volatilize rapidly, as they probably consist almost only of propylene glycol and/or vegetable glycerin. although e-cigs initially produced higher particle mass and number concentrations, their emissions had a much shorter lifetime of approximately 10-20 seconds, in comparison with the conventional and hand-rolling cigarette particulate emissions which had a dissipation time of approximately 1.4 hours in a 35 m3 room. Therefore, e-cigs may pose less risk to bystanders than conventional cigarettes due to the rapid volatilization of their emissions. however, further studies are needed to confirm these findings and assess the potential health risks associated with e-cig use.
Citation
Lampos S, Kostenidou E, Farsalinos K, et al. Real-Time assessment of E-Cigarettes and Conventional Cigarettes Emissions: aerosol Size Distributions, Mass and Number Concentrations. Toxics. 2019;7(3). doi:10.3390/toxics7030045
