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Respiratory dose assessment of inhaled particles: continuing progress
Citation:
KIM, C. S. Respiratory dose assessment of inhaled particles: continuing progress. Presented at American Association for Aerosol Research Annual meeting, Minneapolis, MN, October 26 - 30, 2009.
Impact/Purpose:
Multi-compartment and micro-area dose analysis opens up the possibility of linking site-specific dose to tissue or cellular responses. Such data would be helpful for improving dose-response analysis in toxicology studies and devising new strategies ofhealth risk assessment
Description:
Internal dose is a key factor for determining the health risk ofinhaled pollutant particles on the one hand and the efficacy ofdrug inhalantsonthe other. Accurateestimation ofrespiratorydose, however, is a difficult task because multiple factors come to play roles in the process. Deposition measurement in human lungs in vivo has been served as a primary basis ofdose estimation. But the data base is largely made up with total and large-compartment regional deposition in healthy young adults breathing under prescribed conditions. Dose information is lacking for different population groups (age, gender and disease), real life exposure environment and applications to specific toxicological responses. Recently, total deposition measurements have been reported for a wide range ofbreathing patterns that can be related to daily activities ofthe general population and refined regional deposition has been reported for the sequential compartments oflung airways using a novel bolus aerosol delivery method. Although limited in scope, some new measurements have been reported in patients with asthma and chronic obstructive pulmonary disease. Besides the in vivo measurements, mathematical modeling and computational fluid dynamic simulation studies have shown a marked progress allowing us to fill the gap ofand extend the existing human data. Multi-compartment and micro-area dose analysis opens up the possibility of linking site-specific dose to tissue or cellular responses. Such data would be helpful for improving dose-response analysis in toxicology studies and devising new strategies ofhealth risk assessment. This is an abstract ofa proposedpresentation and does not necessarily reflect EPA policy.