Fiber deposition in human upper airway model.
Department of Environmental Health Sciences, The Johns Hopkins University, Baltimore, Maryland, 1989 Jan; :1-3
The possibility that airborne fibers may behave differently than spherical particles in their deposition in the upper airways was examined. Deposition measurements were taken in a replicate model of the upper human airways above the larynx with well characterized glass fiber aerosols typical of glass fibers in normal use. Deposition was measured as a function of fiber length, diameter, and flow rate through the airways. The overall deposition of the aerosols in the nasal airways ranged from 10 to 90 percent. The deposition increased with flow rate and was also somewhat higher with nasal hair stimulant in the anterior vestibule. There was no dependency demonstrated between the effect of fiber diameter and inertial theory, suggesting that interception is an important factor. Deposition occurred mainly anterior to the nasopharynx, equally divided between the vestibule and the turbinate region. The establishment of the anterior nasal region as the prime site for interception deposition was verified by the lack of significant deposition in the nasopharynx and larynx during nasal breathing. No attempt was made to study deposition during oral breathing. The authors conclude that the human nasal passage is able to remove a significant fraction of inhaled fibers, most of which will be physically cleared and others of which will be cleared to the gastrointestinal tract. No long term effect is expected from fibers deposited in the nasal region and cleared physically.
NIOSH-Grant; Pulmonary-system-disorders; Inhalation-studies; Asbestos-fibers; Fiber-deposition; Humans; Fibrous-dusts
Environmental Health Sciences Johns Hopkins University 615 North Wolfe Street Baltimore, MD 21205
Final Grant Report
NTIS Accession No.
Department of Environmental Health Sciences, The Johns Hopkins University, Baltimore, Maryland
Johns Hopkins University, Baltimore, Maryland