You are here:
DEVELOPMENT OF THE HUMAN LUNG MEASURED BY AEROSOL-DERIVED AIRWAY MORPHEMETRY (ADAM).
Citation:
ZEMAN, K. AND W. D. BENNETT. DEVELOPMENT OF THE HUMAN LUNG MEASURED BY AEROSOL-DERIVED AIRWAY MORPHEMETRY (ADAM). Presented at International Society for Aerosols in Medicine, Perth, AUSTRALIA, March 14 - 18, 2005.
Description:
We measured, in vivo, the airspace calibers of the small airways and alveoli by ADAM in the lungs of children of ages 6 to 18 years and adults aged 18 to 80 years. ADAM utilizes the gravitational settling time of inhaled monodisperse particles to infer the vertical distance to the airway surfaces at sequential depths into the lung. Previously, we identified anatomical lung features, EADtrans and EADmin, associated with the caliber of the transitional respiratory bronchioles and the alveoli, respectively, and VLDtrans, a measure of conducting airway volume. In the current study we found that EADmin increased with age from 6 to 22 years (p=0.003, EADmin ?m = 2.97(age years)+166), which generally accounts for the increase in TLC observed over this age range: TLC increased approximately with the third power of EADmin (p<0.001, TLC ml = 0.002(EADmin ?m)2.7). EADtrans did not increase with age nor TLC, averaging 572 ?m, but increased primarily with subject height (p=0.03, EADtrans ?m = 2.15(height cm) + 220). VLDtrans scaled linearly with lung volume (p<0.001), but VLDtrans relative to TLC did not change with age, 7.04 ? 1.55 %. The data indicates that lung volume enlarges by increasing the size rather than number of alveoli after 6 years. Funded by USEPA Cooperative Agreement CR829522 but does not necessarily reflect EPA policy.