- Researchers measuring airborne particles from two popular vape devices found exhaled aerosol returned to near background levels within around 20 seconds.
- Each puff produced a short spike in particle levels of about 500-900 particles per cubic centimetre.
- Measurements were taken two metres from the person vaping in a real-world indoor environment.
- The study says vape aerosol particles “rapidly decrease in the environment due to evaporation.”
Particles released into the air when someone exhales vape aerosol disperse quickly and return to background levels within seconds, according to a study measuring airborne particles from two modern vaping devices.
Researchers examined particulate matter produced by two last-generation vape devices – Juul and Just Fog – in a real-world indoor environment.
The report, published in the peer-reviewed medical journal Pulmonology, monitored particle levels while volunteers used the devices in a 48-square-metre room, with measuring equipment placed around two metres away from the user.
The team monitored particle levels while volunteers used the devices in a 48-square-metre room, with measuring equipment placed around two metres away from the user.
Brief spikes in particle levels
During the experiments, each puff produced a temporary rise in particle concentrations.
Particle levels increased to peaks of around 500 to 900 particles per cubic centimetre immediately after the aerosol was exhaled. But the spikes were short-lived.
According to the study, particle concentrations fell rapidly and returned to almost background levels in about 20 seconds.
The researchers say this happens because the droplets that make up vape aerosol evaporate quickly after being released into the air. As the paper explains, the particles “rapidly decrease in the environment due to evaporation.”
Testing real-world use
The study was designed to replicate typical indoor vaping conditions rather than a sealed laboratory chamber.
Two volunteers used the devices following a standardised puffing pattern while instruments continuously measured particle concentrations in the air.
Participants first took three warm-up puffs, followed by ten puffs over several minutes, allowing researchers to observe how particle levels changed during normal use.
Each puff produced the same pattern – a brief spike in airborne particles followed by rapid dispersion.
Distance from the user
The monitoring equipment was positioned approximately two metres away from the person vaping, roughly the distance between people in many indoor settings.
At that distance, particle concentrations rose slightly during each puff but quickly dropped back to background levels already present in the room.
The researchers say the findings show how quickly the aerosol disperses once it mixes with surrounding air.
Why vape aerosol behaves differently
The study highlights that particles from vaping behave differently from particles produced by combustion.
Cigarette smoke contains solid particles formed by burning tobacco. Vape aerosol, by contrast, consists largely of liquid droplets made from substances such as propylene glycol and glycerol.
Because these droplets evaporate rapidly, they do not remain suspended in the air for long periods.
The authors conclude that aerosol particles from these devices “rapidly decrease in the environment” due to evaporation processes.
While exhaled aerosol can temporarily increase particle levels indoors, the measurements show that these increases are brief and concentrations quickly return to normal background conditions.
