cough cloud

The discussion about the effectiveness of wearing masks to stop the spread of COVID-19 produced images of the cough cloud. There was debate about how far the cough cloud, the spray of tiny droplets emitted from someone’s mouth when they coughed, would carry. Research shows, sadly, that it goes a lot further than people thought and that social distancing at the current standard distance of 1.5 metres is not enough to deal with it. 

 There are many factors that affect the cough cloud. The temperature and humidity of the cloud will cause variation in the spread.  Whether the  coughing is in an enclosed space or an open space with free passage of air is also important. The first impact of the cough spray is the most forceful with the droplets dispersing broadly after that so wearing a mask can have a significant effect on reducing the danger.  The major surprise in the images of the cloud was the indication of how far the cloud travelled.