Prof. dr. Detlef Lohse and his team from the Physics of Fluids group at the University of Twente will investigate the effect of aerosols in the spreading of viruses like the coronavirus. Together with the University Medical Center Groningen (UMCG) and Rob Hagmeijer from the UT research group Technische Stromingsleer, they start a new project that will increase the understanding of how respiratory droplet spread in various circumstances. ZonMW is financing the project with €500.000.
Up until recently, the World Health Organization (WHO) and the Dutch National Institute for Public Health and the Environment (RIVM) have underestimated the role aerosols – droplets smaller than 200 micrometres – have in the spreading of viruses. The assumptions of the RIVM were based on an old model made by William F. Wells from the 1930s, who assumed that droplets with a diameter of 5-10 micrometre would evaporate too quickly to become a problem.
The lifetime of these aerosols is much longer than previously thought. “The droplets leave your body with the humidity of your breath. The humid environment makes it harder for the droplets to evaporate”, says Lohse. Inside, the risk of infection is very big. Especially when there is poor ventilation and you have to speak aloud.
Lohse and his team will analyse the lifetime of aerosols with both simulations and experiments in many different situations. Lohse says: “We will study the effect of coughing, speaking, screaming and facemasks in different environments on the lifetime of these droplets. If the corona pandemic makes one thing clear, it is that we still do not know enough about the fluid dynamics of sneezing, coughing, speaking and even simply breathing. Answers are urgently needed, and in times like this, the basic research on this subject is no longer a niche but a key discipline.”
The research project is a collaboration with UMCG in Groningen. In Groningen, they will analyze the number of viruses inside the droplets and whether that number is high enough for an infection. Together, the researchers want to learn about the role of aerosols in the spreading of COVID-19.
The research will be done in the Physics of Fluids group, the Max Planck Center for Complex Fluid Dynamics (both Faculty of TNW and MESA+) and UMCG (Groningen). Detlef Lohse is Distinguished Professor of Physics of Fluids at the University of Twente. He is one of the initiators of the UT-campus based Max Planck Center for Complex Fluid Dynamics.