Particulate pollution interactions with indoor surfaces: measurement and modelling for risk assessment and contaminant control.

In the urban environment, there is strong evidence that fine particulates associated with vehicular emissions are linked with respiratory problems and an increase in mortality. The population sector most at risk is the elderly who spend much of their time indoors; consequently, the infiltration of these particles and their subsequent behaviour indoors is of primary concern. The deposition of aerosol particles in the respiratory system and on indoor surfaces is a process governed by particle size; in addition to providing risk assessment data, an understanding of the interaction of particles with indoor surfaces can be applied to the design of systems for enhancing indoor aerosol deposition and thus inhibiting inhalation exposure. This paper describes experiments using tracer-labelled aerosols, in a range of monodisperse size distributions representative of real particulate pollutants, to study aerosol deposition on surfaces with representative roughness. Some preliminary data, exhibiting electrostaticallyenhanced aerosol deposition are also presented. In order to make these data widely accessible, the experimental results are used to aid in the development of a CFD code by providing validation data. Simulations are described for a room-sized enclosure with representative indoor surfaces, to illustrate the influence of internal building surface characteristics on indoor aerosol concentration modification.