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Continuous deposition of workplace pollutant particles on lung airways
during respiratory actions seriously threatens the lung health of persons
performing tasks in polluted environments. While inhalation-deposition
relationships have been explored, the impact of exhalation on the deposition
of polydisperse particles remains unclear. This study aims to analyze the
exhalation-driven deposition of fine and coarse occupational pollutant
particles in polydisperse form, considering varying levels of physical activity.
Computer simulations are conducted on the airway section G3-G4 to study
the patterns of airflow dynamics and deposition of grain dust, coal fly ash, and
bituminous coal particles across a spectrum of activity intensities, utilizing
idealized and realistic lung models. Key findings include the observation of
early emergence of secondary flows in the real model compared to the
idealized model, a notable shift in deposition patterns towards the postbifurcation zones, and the influence of physical activity intensity on particle
deposition. Additionally, deposition primarily occurs near the cranial ridge
during inhalation, while exhalation leads to deposition in pre- and postbifurcation zones. The effect of gravity on deposition is more pronounced at
lower flow rates but diminishes at higher flow rates. PM2.5 deposition isxv
minimal and random in the idealized model but becomes more significant and
consistent in the real model, with substantial deposition rates observed for
PM10 particles. This research underscores the increased risk of lung diseases
for workers in polluted environments during vigorous activity.