The Influence of Air and Water Conditions on the Generation of Bioaerosols in the Building Drainage System

Evidence for the transit of pathogens on aerosols within the building drainage system is supported by a small but diverse body of evidence from the field, taking in a variety of pathogens, settings, and methods. Previous work at Heriot-Watt suggested that particle counts in a building-scale model drainage system were influenced by the relative humidity (RH) of the air in the system. We here extend this work, systematically varying the air velocity and RH, with conditions reflecting those observed in the field. Further, aerosol water activity was varied using different concentrations of aqueous sodium chloride. These results move us towards a quantitative description of bioaerosol transmission via the building drainage system.