London: Researchers have developed a new online tool that can calculate the risk of Covid-19 transmission in poorly-ventilated places, showing that when two people are in such spaces and neither is wearing a mask, prolonged talking is far more likely to spread the novel coronavirus than a short cough.
The research, published in the journal Proceedings of the Royal Society A, also shows that the virus spreads further than two meters in seconds in poorly-ventilated spaces.
The researchers, from the University of Cambridge and Imperial College London in the UK, noted that when speaking, we exhale smaller droplets, or aerosols, which spread easily around a room, and accumulate if ventilation is not adequate. In contrast, coughing expels more large droplets, which are more likely to settle on surfaces after they are emitted, they said.
The researchers developed Airborne.cam, a free, open-source tool that helps users understand how ventilation and other measures affect the risk of indoor transmission, and how that risk changes over time. Airborne.cam can be used by those managing public spaces, such as shops, workplaces and classrooms, in order to determine whether ventilation is adequate.