Characterization of mass distribution in a biomimetic aerosol exposure system

Abstract

Objective

Lack of biomimicry in geometry and flow conditions of emissions systems for analytical testing and biological exposure has led to fundamental limitations, including a poor understanding of dose delivered to specific airway locations. This work characterizes mass distribution of a JUUL® brand e-cigarette in a Biomimetic Aerosol Exposure System (BAES).

Materials and Methods

A combination of mass balance, direct measurements, and inferences based on direct measurements were used to characterize regional and local dose as a function of system flow path configuration and emissions topography profile.

Results

Doses produced by the emissions topography profile with only puffing were significantly different from profiles with clean air inhalation following puffs. Mass characterization results support that dose can be manipulated using flow path geometry. Local and regional deposition was mapped throughout the system.

Discussion and Conclusions

We estimate the fraction of yield to the mouth deposited at several locations throughout the system for a variety of puffing and respiration topographies and show that emissions topography profile and system flow path geometry affect dose. This work provides proof-of-concept for assessing mass distribution as a function of aerosol generator (e-cigarette product), user airway geometry, and inhalation and puffing topography.

Keywords:

• ENDS
• e-cigarette
• exposure system
• smoking robot
• airway model
• aerosol science

Acknowledgments

The authors would like to acknowledge Gary DiFrancesco for machining parts used throughout the emissions system and Shehan Jayasekera for upgrading PES Controller software to account for inhalation. We thank Nathan Eddingsaas for assistance with developing the analysis protocol for absorbance measurements and Chamodhi Ravihansi Polgampola Ralalage for preparing e-liquid. We acknowledge Claudia Vondra for developing the initial plate reader analysis code and assisting in mass balance experiments and Katherine Walton for collecting experimental data associated with assessing particle size distribution.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, ECH, upon reasonable request.

Additional information

Funding

This work was supported by Rochester Institute of Technology internal funds; National Institute of Environmental Health Sciences (NIEHS) of the National Institutes of Health and FDA Center for Tobacco Products (CTP) under Award Number R21ES029984; National Institute on Drug Abuse of the National Institutes of Health and the Food and Drug Administration’s (FDA) Center for Tobacco Products (CTP) under Award Number R21DA050852.