AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Aerosol Deposition in Nasal Airway Replicas: Infants, Children, and Adults
Mindy Guo, YUE ZHOU, Jinxiang Xi, Hammad Irshad, Yung-Sung Cheng, Lovelace Respiratory Research Institute
Abstract Number: 76 Working Group: Health Related Aerosols
Abstract Understanding aerosol deposition in the human respiratory tract is crucial in assessing health effects of environmental exposure and improving inhalation drug delivery. The nasal airway is the first line of defense for the entire respiratory system’s functions and serves as a filter of ambient aerosols during inhalation. However, there is significant variability of particle deposition in nasal airways of infants, children, and adults due to age-related differences in airway geometry and breathing rate. The previously published particle deposition models were based on similar nasal airway geometry. In such cases, one model can only be used in one age group to estimate particle deposition. The estimated particle deposition is crude and the calculation of deposition efficiency requires several models to cover all age groups. In addition, it does not take individual geometric variability into account.
We developed a simple way to investigate nasal aerosol deposition in all age groups in this study. We conducted in vitro testing of micrometer particle deposition in nasal airways for infants, children, and adults by using five nasal replicas (10-day, 7-month, 3-year, 5-year, and 53-year) at similar breathing conditions. Monodisperse oleic acid aerosols ranging in size between 2 and 28 micro-meters were delivered into replicas at the rest condition. The size range covers the deposition efficiency up to 100%. The combined data set of infants, children, and adults demonstrated that the aerosol deposition in the nasal airway is strongly dependent on the particle size and pressure drop. Since the method is pressure drop based, it is not influenced by individual geometric variability. In conclusion, our study proved that the deposition efficiency can be calculated based on a single empirical equation for all age groups.