Comparative numerical modeling of inhaled micron-sized particle deposition in human and rat nasal cavities

Abstract

Micron-sized particle deposition in anatomically realistic models of a rat and human nasal cavity was numerically investigated. A steady laminar inhalation flow rate was applied and particles were released from the outside air. Particles showing equivalent total particle deposition fractions were classified into low, medium and high inertial particle. Typical particle sizes are 2.5, 9 and 20 μm for the human model and 1, 2 and 3 μm for the rat model, respectively. Using a surface-mapping technique the 3D nasal cavity surface was “unwrapped” into a 2D domain and the particle deposition locations were plotted for complete visual coverage of the domain surface. The total surface area comparison showed that the surface area of the human nasal model was about ten times the size of the rat model. In contrast, the regional surface area percentage analysis revealed the olfactory region of the rat model was significantly larger than all other regions making up ∼55.6% of the total surface area, while that of the human nasal model only occupying 10.5%. Flow pattern comparisons showed rapid airflow acceleration was found at the nasopharynx region and the nostril region for the human and rat model, respectively. For the human model, the main passage is the major deposition region for micro-particles. While for the rat model, it is the vestibule. Through comparing the regional deposition flux between human and rat models, this study can contribute towards better extrapolation approach of inhalation exposure data between inter-subject species.

• CFD
• nasal cavity
• particle deposition
• rat–human extrapolation
• surface-mapping

Acknowledgements

The authors would like to thank Dr Rui Chen and Dr Chunying Chen from the Chinese Academy of Science for their fruitful discussions. Also, special thanks are given to Mr Ke Sun for his kind assistance in the early model reconstruction stage.

Declaration of interest

The authors report no conflict of interest. The authors alone are responsible for the content and writing of this article.

Jingliang Dong especially thanks for the financial support received from the RMIT University in the scheme of Higher Degree by Research Publications Grant.

This work was financially supported by the Australian Research Council (ARC project ID DP120103958) and the National Natural Science Foundation of China (NSFC 21277080).