Particle deposition in the upper respiratory airway has important implications for the chemistry community with respect to the transport and inhalation of atmospheric particles as well as the design and use of nanoparticles and nanoparticles for industrial or medical concerns. However, studying particle deposition in the respiratory system using human adult subjects is a significant undertaking. Additionally, such studies are unfeasible for infants and children, while the potential for negative effects from particle deposition on their development makes such studies more essential. In an attempt to reduce the need for human subjects, we have used CT scans to print models of the human respiratory system of a toddler, child, and adult. We then aerosolized Arizona Test Dust (ATD) to investigate the deposition of 1-10 µm particles within the upper airways of these models. To understand the extent to which increasing particle size increases particle impaction and thus deposition with respect to subject age, we compared the number of particles that passed through each model with an unobstructed reference. As the respiratory rate of humans varies with activity level, various flow rates were used to understand how altering the flow rate changed particle deposition. By standardizing the data with respect to particle size and flow rate, the three models could be directly compared. Through this comparison, we determined that there were statistically significant differences between the models with respect to the amount of particles deposited at each specific size. In addition, the deposition of particles by size in the adult human model is comparable to existing studies of particle deposition in human adults of various ages. Overall, printed models of the upper respiratory airway of humans provide a comparable way to determine particle deposition in humans.

Characterizing the effect of particle size on deposition in printed human models

255th National Meeting (2018)

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