||Dosimetry Model for Hygroscopic Sulfate Aerosols in Selected Temperature and Relative Humidity Patterns.
Martonen, T. B. ;
Miller, F. J. ;
||Northrop Services, Inc., Research Triangle Park, NC.;Health Effects Research Lab., Research Triangle Park, NC.
Mathematical models ;
Public health ;
Particle size ;
Sulfuric acid ;
Ammonium sulfate ;
Air pollution effects(Humans) ;
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Sulfate aerosols (NH4HSO4,(NH4)2SO4 and H2SO4) are of international health effects concern because of their global prevalence and potential irritant or toxic effects on human health. To assess hazards following inhalation exposure, the total dose delivered to the human respiratory tract and its regional distribution must be determined. It is known that such information can be expressed as a function of the mass median aerodynamic diameter (MMAD) of an inhaled aerosol. Sulfate aerosols are hygroscopic and will have changing particle sizes and densities upon absorption of H2O vapor in the humid environment of the human respiratory tract. The authors have developed a new mathematical description of inhaled particle behavior suitable for dosimetry of the human nasopharyngeal and oropharyngeal compartments, larynx, and tracheo-bronchial (TB) airways. Results show that the hygroscopic characteristics of ambient sulfate aerosols can greatly affect total dose deposited and the relative distribution of particle mass among airways.