There is increasing awareness that water and drainage systems in buildings are reservoirs for pathogenic microorganisms. Studies have shown that water and drainage systems can generate small droplets and aerosols which can potentially cause infection through surface contamination or inhalation. While these are widely measured using bioaerosol samplers, particle samplers and surface sampling techniques this quantifies the consequence rather than the mechanism that results in the contamination.

To fully understand risk and determine the most effective engineering solutions it is necessary to consider the physics behind the generation of droplets and aerosols and the factors that influence their dispersion and deposition in air. This is not straightforward - all building water and drainage systems involve a transient interaction between water and air, which represents a complex multi-phase fluid dynamics problem. This talk provides an overview of some of this complex flow physics, considering the different sources of droplets and aerosol, some of the factors that affect their behaviour and what this might mean for understanding risk and assessing solutions.

Professor Catherine Noakes, School of Civil Engineering, University of Leeds