Inhalation of elevated
levels of particulate air pollution has
been shown to elicit the onset of adverse health effects in humans,
where the magnitude of the response is a product of where in the lung
the particulate dose is delivered. At any point in time during inhalation
the depositional flux of the aerosol is a function of the radius of
the droplet, thus a detailed understanding of the rate and magnitude
of the mass flux of water to the droplet during inhalation is crucial.
In this study, we assess the impact of aerosol hygroscopicity on deposited
dose through the inclusion of a detailed treatment of the mass flux
of water to account for the dynamics of particle size in a modified
version of the standard International Commission on Radiological Protection
(ICRP) whole lung deposition model. The ability to account for the
role of the relative humidity (RH) of the aerosol prior to, and during,
inhalation on the deposition pattern is explored, and found to have
a significant effect on the deposition pattern. The model is verified
by comparison to previously published measurements, and used to demonstrate
that ambient RH affects where in the lung indoor particulate air pollution
is delivered
