Multicomponent aerosol particle deposition in a realistic cast of the human upper respiratory tract

Abstract

Inhalation of aerosols generated by electronic cigarettes leads to deposition of multiple chemical compounds in the human airways. In this work, an experimental method to determine regional deposition of multicomponent aerosols in an in vitro segmented, realistic human lung geometry was developed and applied to two aerosols, i.e. a monodisperse glycerol aerosol and a multicomponent aerosol. The method comprised the following steps: (1) lung cast model preparation, (2) aerosol generation and exposure, (3) extraction of deposited mass, (4) chemical quantification and (5) data processing. The method showed good agreement with literature data for the deposition efficiency when using a monodisperse glycerol aerosol, with a mass median aerodynamic diameter (MMAD) of 2.3 μm and a constant flow rate of 15 L/min. The highest deposition surface density rate was observed in the bifurcation segments, indicating inertial impaction deposition. The experimental method was also applied to the deposition of a nebulized multicomponent aerosol with a MMAD of 0.50 μm and a constant flow rate of 15 L/min. The deposited amounts of glycerol, propylene glycol and nicotine were quantified. The three analyzed compounds showed similar deposition patterns and fractions as for the monodisperse glycerol aerosol, indicating that the compounds most likely deposited as parts of the same droplets. The developed method can be used to determine regional deposition for multicomponent aerosols, provided that the compounds are of low volatility. The generated data can be used to validate aerosol deposition simulations and to gain insight in deposition of electronic cigarette aerosols in human airways.

Keywords:

• Aerosol particle deposition
• regional deposition
• lung cast
• respiratory tract
• monodisperse glycerol aerosol
• multicomponent aerosol
• gas chromatography-mass spectrometry

Acknowledgements

The research described in this report was funded by Philip Morris Products S.A., Switzerland (part of Philip Morris International (PMI) group of companies) and supported by the Brno University of Technology (BUT) project FSI-S-14-2355.

Disclosure statement

This research was conducted by PMI and BUT employees and with PMI funding. The authors had full access to all research data and ensure their integrity as well as the accuracy of the data analysis.

Additional information

Funding

The research described in this report was funded by Philip Morris Products S.A., Switzerland (part of Philip Morris International (PMI) group of companies) and supported by the Brno University of Technology (BUT) project FSI-S-14-2355.