Gravity-driven ventilation heterogeneity shapes aerosol deposition: a full-scale digital lung modeling study

Area of Science:

• Pulmonary medicine
• Computational fluid dynamics
• Toxicology

Background:

• Hazardous aerosol exposure is a major cause of lung diseases.
• Current inhalation risk assessments using simplified models do not account for lung ventilation heterogeneity.
• This limits accurate assessment of regional aerosol deposition and associated risks.

Purpose of the Study:

• To develop an advanced digital lung model simulating aerosol deposition during normal breathing.
• To investigate the correlation between airflow dynamics, gravity, and regional aerosol deposition in the human lung.
• To translate deposition patterns into biologically relevant risk metrics for hazardous aerosols.

Main Methods:

• Developed a full-scale digital lung model with nonlinear compliance and gravity effects.
• Simulated deposition of aerosol particles (0.1-10 µm) during quiet, upright breathing.
• Quantified regional deposition density and exposure times to cytotoxicity thresholds using welding fume as an example.

Main Results:

• Identified a gravity-dependent, heterogeneous deposition pattern with highest intensity in lower lung lobes.
• Pinpointed three deposition hotspots in the right and left lower lobes for specific particle sizes (3 µm and 10 µm).
• Demonstrated the model's capability to calculate regional deposition and exposure risks.

Conclusions:

• The digital lung model accurately replicates human lung anatomy and ventilation dynamics.
• It provides a non-invasive platform for evaluating temporospatial inhalation risks from hazardous aerosols.
• This model enhances understanding of lung vulnerability to inhaled pollutants.