Currently there is little understanding of how microorganisms in water systems are dispersed into the environment and the potential risks associated with this. The proposed project aims to model the release of microorganisms from showers to quantify occupant exposure. This will involve particle and bioaerosol measurements from an experimental shower system at PHE and development of a CFD model to simulate the dispersion of water droplets and microorganisms from the shower head. Combing the data of these two elements will enable the modelling of the evaporation and transport of droplets in a bathroom environment. In this way the influence of parameters such as temperature, humidity and ventilation on the fate of microorganisms within the droplets.