Physicists and medical researchers from The University of Amsterdam (UvA) have discovered that small cough droplets remain in the air for minutes, especially in rooms that are not or poorly ventilated. The researchers asked healthy subjects to speak and cough, and then analyzed the droplets released by laser light.
The larger drops released fall to the ground within a second and have a lower chance of transmitting viruses. The researchers discovered that the smaller droplets can linger in the air for several minutes. After someone coughs once, it takes about five minutes for the number of small droplets in the air to halve. They are therefore much more dangerous in the transmission of the coronavirus.
The results are important in order to take better precautions against the spread of the coronavirus. Keeping enough distance from each other is not enough to limit the risks. Also, the use of apps that only measure proximity to others is insufficient. Good ventilation in public spaces, for example in public transport, in care homes – but also in commercial spaces – is therefore crucial in the fight against COVID-19.