Fast walking in narrow spaces behind a group of people can significantly increase Covid-19 transmission risk, especially in children, according to a study which says virus-laden respiratory droplets can trail behind infected individuals moving through such corridors. The results of the computer simulation, published in the journal Physics of Fluids, underscored the importance of the shape of spaces in predicting how virus-laden droplets move through the air.
While earlier studies highlighted the influence of objects, like glass barriers, windows, and air conditioners on airflow patterns and virus spread, the scientists from the Chinese Academy of Sciences in Beijing said these simulations usually assumed large, open indoor spaces. However, the effect of nearby walls, like those that might exist in a narrow corridor have not been considered, the researchers added.
According to the current study, if a person walking in a corridor coughs, their breath expels droplets that travel around and behind their body, forming a wake in the same way a boat forms a wake in water as it travels.The research revealed the existence of a “re-circulation bubble” directly behind the person’s torso and a long wake streaming out behind them at approximately waist height.