Size Distribution and Deposition in Human Respiratory Tract: Particle Mass and Number

To determine the regional deposition of particulate matter in human lungs for a variety of steady-state engine operating conditions, fuel formulations and combinations of after treatment devices, and to characterize the size, distribution and mass emission rates of particulate matter emissions from off-road and on-highway heavy-duty vehicles operating on conventional diesel, and ultra-low sulfur synthetic diesel fuels. Background: Regional deposition is defined as the fraction of particles inspired which is deposited in the region of interest. The model for polydispersed aerosols (0.5 um to 15 um) developed Kobritch, Rudolf, ,and Stahlhofen (1994) was employed. However, regional deposition in humans has so far only been measured with, particles with diameters greater than 100 nm.