Regional aerosol deposition in human upper airways

Technical Report · Wed Nov 01 00:00:00 EST 1989

DOI:https://doi.org/10.2172/5367473· OSTI ID:5367473

Swift, D. L.

During the report period significant progress on the quantitative understanding of regional upper airway deposition of airborne particle has been realized. Replicate models of the human upper airways obtained from post-mortem casting of the nasal, oral, pharyngeal, laryngeal and upper tracheal regions and in vivo magnetic resonance imaging (MRI) of the same regions of adults and children have been employed to determine the overall and local deposition characteristics of aerosols in the ultrafine (1--100 {mu}m diameter) and fine (0.8--12 {mu}m diameter) region. Studies have been carried out for both nasal and oral breathing during inspiratory and expiratory flow at constant flow rates representative of rest and states of exercise. The results of these investigations indicate that particles in the size range of unattached'' radon progeny (1--3 nm) are deposited in both the nasal and oral passages with high efficiency (60--80%) for both inspiration and expiration, with the nasal deposition being somewhat greater (5--10%) than oral deposition. The effect of flow rate on upper airway deposition for both pathways is not great; data analysis indicates that the deposition for all flow rates from 4--50 liters/minute can be grouped by plotting deposition vs Q-{sup 1/8}, where Q is flow rate, a far weaker dependency than observed for inertial deposition. Diffusional transport is the primary mechanism of deposition, and size dependence can be accounted for by plotting, deposition percent vs D{sup n} where D is particle diffusion coefficient and n ranges from 0.5--0.66. 2 refs.

• Research Organization: Johns Hopkins Univ., Baltimore, MD (United States)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: FG02-88ER60655
• OSTI ID: 5367473
• Report Number(s): DOE/ER/60655-2; ON: DE90003314; TRN: 89-031979
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AEROSOLS
INHALATION
RESPIRATORY SYSTEM
BIOLOGICAL ACCUMULATION
AGE DEPENDENCE
AIR FLOW
AIR POLLUTION
BIOLOGICAL FUNCTIONS
COMPARATIVE EVALUATIONS
DOSE-RESPONSE RELATIONSHIPS
DOSIMETRY
FLOW RATE
HEALTH HAZARDS
HUMAN POPULATIONS
LUNGS
MAN
PARTICLE SIZE
PARTICLES
PHARYNX
POLLUTANTS
PROGRESS REPORT
RISK ASSESSMENT
SAMPLING
SORPTIVE PROPERTIES
TESTING
ANIMALS
BODY
COLLOIDS
DIGESTIVE SYSTEM
DISPERSIONS
DOCUMENT TYPES
FLUID FLOW
FUNCTIONS
GAS FLOW
HAZARDS
INTAKE
MAMMALS
ORGANS
POLLUTION
POPULATIONS
PRIMATES
SIZE
SOLS
SURFACE PROPERTIES
VERTEBRATES
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)
560300 - Chemicals Metabolism & Toxicology