The study titled, Systems toxicology meta-analysis of in vitro assessment studies: biological impact of a candidate modified-risk tobacco product aerosol compared with cigarette smoke on human organotypic cultures of the aerodigestive tract, analysed three types of human cultures in vitro before and after exposure to e-cigarette vapour and cigarette smoke.
The researchers observed lower toxicity levels in all cultures following exposure to e-cigarette vapour in comparison to cigarette smoke. “Lower toxicity was observed in all cultures following exposure to THS2.2 aerosol compared with 3R4F CS [cigarette smoke],” read the study abstract.
In line with numerous previous studies indicating that the risks from vaping are minimal in when compared to those from smoking, this study indicated that cigarette smoke increases oxidative stress, and inflammatory responses in our system. In comparison, the effects of vapour are not only less intense, but also more transient.
Exhaled vapour evaporates within seconds
For the latter, the study respondents were asked to use e-cigarettes or smoke conventional cigarettes at different distances from a heated mannequin, representing a bystander, and under different room ventilation conditions. In the meantime, the researchers measured aerosol particle concentrations and size distributions at the mannequin’s position.
“Particle size measurements showed that exhaled e-cigarette particles were smaller than those emitted during smoking conventional cigarettes and evaporated almost immediately after exhalation, thus affecting the removal of particles through evaporation rather than displacement by ventilation,” reported the study.
The study authors said that this study is a clear indication that vaping indoors is unlikely to pose any health risks to bystanders. “Exhaled e-vapour aerosol particles have a different chemical composition to cigarette smoke and here we show the physical properties are also significantly different.