Objectives: Electronic cigarette (ECIG)-generated aerosol contains particulate matter with a diameter less than 2.5 microns (PM2.5). Particles of this size may be injurious to the health of those who inhale them. Few studies have assessed the relationship between ECIG aerosol PM2.5 and ECIG liquid ingredients or ECIG device power.
Methods: Two studies were conducted in which participants generated aerosols with ECIGs: in one, ECIG liquids contained various vegetable glycerin/propylene glycol ratios and in the other, ECIG devices varied by electrical power output.
Results: Results indicate that, in general, PM2.5 increases as the ratio of vegetable glycerin to propylene glycol increases, or as device power increases.
Conclusions: Regulating ECIG PM2.5 emissions to protect non-users requires an understanding of all the factors that influence these emissions.
Keywords: PM2.5; device power; electronic cigarette; particulate matter; propylene glycol; vegetable glycerin.