The risk of contagion is highest in indoor spaces but can be reduced by applying all available measures to combat infection via aerosols. Here is an overview of the likelihood of infection in three everyday scenarios, based on the safety measures used and the length of exposure
Six people get together in a private home, one of whom is infected. Some 31% of coronavirus outbreaks recorded in Spain are caused by this kind of gathering, mainly between family and friends.
Irrespective of whether safe distances are maintained, if the six people spend four hours together talking loudly, without wearing a face mask in a room with no ventilation, five will become infected, according to the scientific model explained in the methodology.
If face masks are worn, four people are at risk of infection. Masks alone will not prevent infection if the exposure is prolonged.
The risk of infection drops to below one when the group uses face masks, shortens the length of the gathering by half and ventilates the space used.
The coronavirus is spread through the air, especially in indoor spaces. While it is not as infectious as measles, scientists now openly acknowledge the role played by the transmission of aerosols – tiny contagious particles exhaled by an infected person that remain suspended in the air of an indoor environment. How does the transmission work? And, more importantly, how can we stop it?