Molecular and Integrative Physiological Sciences Program
Dates of Research:
September 15, 2003 — August 31, 2009
Knowledge on particle deposition in children’s lungs is essential for realistic estimates of health risks posed by aerosol exposure of children, and also to determine the correct dose for therapeutic drugs delivered by inhalation, but this problem has received little attention. Currently, it is assumed that children’s lungs are a small-size version of the adult one, and scaled-down adult lung models are used for the assessment of deposition efficiency. We hypothesize that age-associated changes in lung anatomy, such as progressive alveolation, lead to major changes in particle mixing and deposition, predicting that deposition peaks in very young children with lungs that have become largely alveolated already but are still small in size. To test this hypothesis, we propose to perform a study combining theoretical and experimental approaches. The results will give us a comprehensive view of the relationship between alveolar geometry and the appearance of chaotic mixing mechanisms in the lung that may result in a sudden change in the extent of particle deposition. The findings of the project may lay down the foundation for realistic and rationally based inhalation dosimetry in children.