Deposition of ultrafine aerosols and thoron progeny in replicas of nasal airways of children
- Inhalation Toxicology Research Inst., Albuquerque, NM (United States)
- National Inst. of Safety Research, Seoul (Korea, Republic of)
- Johns Hopkins Univ., Baltimore, MD (United States)
The deposition efficiencies of ultrafine aerosols and thoron progeny were measured in youth nasal replicas. Clear polyester-resin casts of the upper airways of 1.5-yr-old (Cast G), 2.5-yr-old (Cast H), and 4-yr-old (Cast I) children were used. These casts were constructed from series of coronal magnetic resonance images of healthy children. Total deposition was measured for monodisperse NaCl or Ag aerosols between 0.0046 and 0.20 {mu}m in diameter at inspiratory and expiratory flow rates of 3, 7, and 16 L min{sup -1} (covering a near normal range of breathing rates for children of different ages). Deposition efficiency decreased with increasing particle size and flow rate, indicating that diffusion was the main deposition mechanism. Deposition efficiency also decreased with increasing age at a given flow rate and particle size. Based on information obtained and information on minute volumes for different age groups, we predicted nasal deposition in age groups ranging from 1.5- to 20-yr-old at resting breathing rates. Our results showed that the nasal deposition increases with decreasing age for a given particle size between 0.001 to 0.2 {mu}m. This information will be useful in deriving future population-wide models of respiratory tract dosimetry. 24 refs., 12 figs., 3 tabs.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-76EV01013
- OSTI ID:
- 200375
- Journal Information:
- Aerosol Science and Technology, Vol. 23, Issue 4; Other Information: PBD: Nov 1995
- Country of Publication:
- United States
- Language:
- English
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