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Deposition of fiber in the human nasal airway.

Su-W-C; Cheng-YS

Aerosol Sci Tech 2005 Sep; 39(9):888-901

http://dx.doi.org/10.1080/02786820500295685

20044488

Inhalation is the main route for aerosol entering the human body. Many occupational lung diseases are associated with exposure to fiber aerosol in the workplace. However, very few studies to date have been conducted for investigating fiber deposition in the human airway. As a result, there is a notable lack of information on the nature of the fiber deposition pattern in the human respiratory tract. With this in mind, this research consisted of a large number of experimental works to investigate the effects of fiber dimension on the deposition pattern for a human nasal airway. Carbon fibers with uniform diameter (3.66 um) and polydispersed length were adopted as the test material. Deposition studies were conducted by delivering aerosolized carbon fibers into a nasal airway replica (encompassing the nasal airway regions from vestibule to nasopharynx) at constant inspiratory flow rates of 7.5, 15, 30, and 43.5 l/min. Fibers deposited in each nasal airway region were washed out and the length distribution was determined by microscopic measurement. The results showed that impaction is the dominant deposition mechanism. Most of the fibers with high inertia deposited in the anterior region of the nasal airway (vestibule and nasal valve). In contrast, fibers with low inertia were found to pass through the entire nasal airway easily and collected on the filter at the outlet. Comparing the deposition results between fibers and spherical particles, our data showed that the deposition efficiencies of fibers are significantly lower than that of spherical particles, which implies that the inhaled fibers could pass through the entire nasal airway comparatively easier than spherical particles. Thus, relatively more fibers would be able to enter the lower respiratory tract.

Aerosols; Aerosol-particles; Fibrous-dusts; Inhalants; Airborne-fibers; Air-sampling; Exposure-levels; Risk-factors; Asbestos-fibers; Asbestos-dust; Particulates; Analytical-processes; Models; Air-flow; Respiratory-irritants; Respiratory-rate; Nasal-cavity; Lungs; Lung-disease; Humans

Wei-Chung Su, Lovelace Respiratory Research Institute, 2425 Ridgecrest Drive, SE, Albuquerque, NewMexico 87108, USA

ASTYDQ

20050901

Journal Article

wsu@LRRI.org

Grant

2005

Grant-Number-R01-OH-003900

9

0278-6826

Aerosol Science and Technology

NM

Lovelace Biomedical & Environmental Research, Albuquerque, New Mexico