Grant: Collaborative Health Research Projects

Aerosol particles may have either positive or negative effects on human health. On the positive side,pharmaceutical aerosols are specifically designed to deliver drugs to the lung, while on the negative side, someparticles in the atmosphere or the workplace have been shown to have a toxic effects on human health. In boththese applications it is important to know the regional particle dosage i.e. the amount of particles that deposit ineach area of the lung. However, existing models to predict regional dosages have not been validated inchildren, and do not apply to low density and nonspherical particles (such as diesel agglomerate particles). Toovercome these limitations, we will construct replicas of portions of the human lungs of children and adultsfrom which particle deposition can be measured and validated models developed. The replicas will be madeusing CT scans of child and adult subjects and a rapid-prototyping machine. Using a variety of experimentaltechniques that we have used previously to study extrathoracic deposition, the particle deposition in the replicaswill be measured without human exposure. Furthermore, experiments will be done with a variety of particlemorphologies and densities, including ultra-low density particles and soot nanoagglomerates. In parallel to thisresearch, and in order to facilitate rapid, on-site field measurements of aerosol exposure, we propose to adaptour airway replicas into an electronic lung. The electronic lung will detect the particles by electricallypre-charging the particles and detecting their deposition by the use electrometers in each region of an artificiallung. This will allow rapid characterization of aerosol exposure directly in terms of how much aerosol depositsin the different lung regions. The results of this research will allow improved measurement and assessment ofthe risks associated with exposure of airborne particulate matter as well as improved respiratory drug delivery,particularly in children, but also in adults. Given the considerable morbidity and mortality associated with bothrespiratory disease and inhalation of airborne particulates, the proposed research will provide importantimprovements to the health of Canadians.