Methods for modeling particle deposition as a function of age

Abstract

The purpose of this paper is to review the application of mathematical models of inhaled particle deposition to people of various ages. The basic considerations of aerosol physics, biological characteristics and model structure are presented along with limitations inherent in modern modeling techniques. Application of the models to children and senescent adults has been largely based on extrapolating anatomical and physiological data from young adults to match the changes observed during growth and aging. Sample results are included for total particle deposition and deposition in the bronchial and pulmonary regions. The models proposed provide particle deposition predictions that are consistent with the scant measurements available. The models discussed appear to be on firm theoretical grounds, but they are largely limited in application to simple aerosols and average individuals. Also, additional validation of the computational predictions is needed.

Exposure to culturable and total microbiota in cultural heritage conservation laboratories

“…Moreover, the particle sizes, shapes, densities, chemical composition and reactivity determine how deep, i.e., which level of the respiratory tract, they will reach and how they will behave. Apart from the enumerated parameters, the mechanism of particle deposition is affected also by the rate of airflow, manner of breathing and pulmonary ventilation, which depends on the age and activity dynamics [48][49][50]. As studies show, particles smaller than 2.5 μm (actinomycetal pseudoconidia, the majority of spores of filamentous fungi occurring in indoor environments) pose the greatest hazard to the health of persons exposed through inhalation.…”

Deposition of micrometer-sized aerosol particles in infant nasal airway replicas

“…A discussion of modeling aerosol deposition in this context including age effects is given by Phalen and Oldham (2001).…”

Inhaler Devices in Infants and Children: Challenges and Solutions

“…32 Once particles reach the lower airways most models predict relatively greater central airways deposition in those under 2 years of age than for the adult though the majority of deposition will still be in the "periphery" of the lung beyond generation 16. [33][34][35][36][37][38][39][40] These models are at best approximations and the predicted doses can alter dramatically with small changes in the parameters used. Moreover it has not been possible to date to conclusively validate the models though attempts have been made with radioisotopes and stable particles in older children.…”