Simulation of aerosol dynamics and deposition of combustible and electronic cigarette aerosols in the human respiratory tract

Introduction:
This text provides an analysis of the impact of aerosol dynamics and deposition of combustible and electronic cigarette aerosols in the human respiratory tract. The authors use the Aerosol Dynamics in Containments (ADiC) model to simulate the physical properties of particle and vapor phase in the human lung. The study compares the dynamic changes of the inhaled aerosols and the resulting deposition patterns between cigarette smoke particles and e-cigarette droplets.

Key Points:

* The ADiC model describes the dynamic changes of inhaled cigarette smoke droplets during puffing, mouth-hold, and inspiration and expiration, considering coagulation, phase transition, conductive heat and diffusive/convective vapor transport, and dilution/mixing.
* The ADiC model has been implemented into a single path representation of the stochastic lung dosimetry model IDEAL to compute particulate phase deposition as well as vapor phase deposition in the airway generations of the human lung.
* The study finds that aerosol dynamics significantly influence the physical properties of particle and vapor phase in the human respiratory tract.
* The number reduction of inhaled aerosol particles is caused primarily by coagulation and less by deposition for both aerosols.
* Hygroscopic growth rates are higher for e-cigarettes than for combustible cigarettes.
* The effect of particle growth on deposition leads to a lower total deposition in the case of cigarette smoke particles and a higher total deposition in the case of e-cigarette droplets relative to their initial size distributions.
* Most of the nicotine is deposited by the vapor phase for both aerosols.

Main Message:
The main message of the text is that aerosol dynamics play a significant role in the deposition and physical properties of particle and vapor phase in the human respiratory tract. The study highlights the importance of considering coagulation, phase transition, conductive heat and diffusive/convective vapor transport, and dilution/mixing in the analysis of inhaled aerosols. The findings suggest that the ADiC model can be a valuable tool in assessing the health risks associated with the inhalation of combustible and electronic cigarette aerosols. The results also indicate that the physical properties of e-cigarette aerosols differ from those of combustible cigarettes, which could have implications for their health effects. Overall, the study underscores the need for further research into the impact of aerosol dynamics on the deposition and health effects of inhaled aerosols.

Pichelstorfer, Lukas, Werner Hofmann, Renate Winkler-Heil, Caner U. Yurteri, and John McAughey. “Simulation of Aerosol Dynamics and Deposition of Combustible and Electronic Cigarette Aerosols in the Human Respiratory Tract.” Journal of Aerosol Science 99 (September 2016): 125–32. https://doi.org/10.1016/j.jaerosci.2016.01.017.