STP1024

    Upper Airway Scrubbing at Rest and Exercise

    Published: Jan 1989


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    Abstract

    The upper respiratory tract removes inhaled toxic or infectious substances from inspired air and thus functions as an important element of the lung's defense systems. Two key parameters that influence the efficiency of this upper airway scrubbing are the rate of ventilation and whether air enters via the nose or the mouth. For a gas of relatively low water solubility, such as nitrogen dioxide, scrubbing efficiency decreases as ventilation rate increases during either nasal or oral breathing; the nose is, however a more efficient scrubber than the mouth at any given ventilation rate. Exercise increases ventilation rate and often, in humans, results in a shift from nasal to oronasal breathing. Increased ventilation and degradation of upper airway scrubbing during exercise can result in greater than expected lung doses; exercise at which minute ventilation is doubled along with a switch from pure nasal to pure oral breathing can increase dose to the lung by six-fold.

    Keywords:

    lung dosimetry, airway scrubbing, oronasal breathing, exercise, air pollution, nitrogen dioxide


    Author Information:

    Kleinman, MT
    Associate professor and assistant professor, Air Pollution Health Effects Laboratory, University of California—Irvine, Irvine, CA

    Mautz, WJ
    Associate professor and assistant professor, Air Pollution Health Effects Laboratory, University of California—Irvine, Irvine, CA


    Paper ID: STP22830S

    Committee/Subcommittee: D22.03

    DOI: 10.1520/STP22830S


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