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COMMENTS ON RECENT DATA FOR PARTICLE DEPOSITION IN HUMAN NASAL PASSAGES
Citation:
Martonen, T. AND Z. Zhang. COMMENTS ON RECENT DATA FOR PARTICLE DEPOSITION IN HUMAN NASAL PASSAGES. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-93/122 (NTIS PB93181105), 1992.
Description:
The deposition of inhaled particles within human nasal passages has important toxicologic and pharmacologic applications. owever, experimental data quantitating factors affecting particle deposition are rare. e have evaluated findings from investigations employing either replica nasopharyngeal (NP) casts or surrogate model airways and compared them to each other and to human subject results. or ultrafine particles, studies using casts and models are incompatible, measured deposition values from the latter being lower by an entire order of magnitude. ossible sources of discrepancies between the data are suggested herein. tudies with diverse NP replicates, however, have yielded consistent deposition data over a wide particle size range, about 0.005 - 7um. ast experiments underestimate, but in a systematic manner, in vivo information over a 0.5 - 3um interval. t is recommended, therefore, that imp replica cast data, rather than NP model airway data, be used to simulate human passages. or extrapolation modeling purposes, an original empirical formula based upon a logistic theory is derived which describes deposition over a particle size range of three orders of magnitude.