Researchers say e-cigarette particle size and deposition change based on factors such as device power, e-liquid composition and vaping practices, according to research published in Chemical Research in Toxicology.

The team observed vaping sessions of 23 volunteers and used these findings to simulate human vaping with a smoking machine. The researchers then collected the aerosol and measured particle size distribution. They also tested the impact of various factors.

Among the results:

  • Higher device power settings and the use of vegetable glycerin-based e-liquids produced larger particles than lower settings and propylene glycol-based liquids.
  • At a fixed puff volume, longer puff durations (in other words, slower air flow) generated significantly larger particles.
  • The researchers estimated that most of the particles were deposited in the lower respiratory tract (the trachea and bronchi), whereas a smaller amount entered the deeper bronchoalveolar regions of the lungs.

Although e-cigarette particles were smaller and less abundant than those generated by regular smoking, they have similar human airway deposition patterns, the researchers say.

Source: American Chemical Society