Characteristics, deposition, and fate of inhaled particulate matter

Accurate estimates of absorption and fate for particulate matter in the respiratory tract are difficult because of complexities in particle composition and morphology. Several deficiencies in information further complicate the ability to make accurate estimates. Available models for making estimates range from single models based on assumed particle size distribution to more-complex models based on a variety of parameters. Most work in the area of estimating particle fate following inhalation has been done on aerosols of known composition. Additional work is needed to categorize properties of inhalable particles with respect to composition in addition to morphology. Additional research is needed to define the effects of pulmonary disease on particle clearance from the lung. Additional research also is needed to better explain the mechanics of clearance from the pulmonary region of the lung.