Deposition of Aerosols in the Lungs: Particle Characteristics

Of the various particle properties that affect deposition in the respiratory tract, particle diameter and particle density are the most commonly considered, since their effect on deposition is well known and important, as has been discussed earlier in this chapter. However, there are several other particle properties that can affect particle deposition in the lungs. These include: 1) electrostatic charge on the particle, which can cause electrostatic forces to enhance deposition; 2) the shape of the particle, which can cause its trajectory to differ from that of a spherical particle and thereby alter its deposition; and 3) volatility of the particle i.e., its ability to condense or evaporate at its surface, which can change its diameter and in turn affect its deposition. In this section, we examine each of these three factors individually.