Long queues outside supermarkets can be annoying to wait in, especially when you have to keep a 6-feet distance from other people, however, it’s not just a pointless precaution. A new video simulation developed by the Aalto University, the Finnish Meteorological Institute, VTT Technical Research Centre of Finland, and the University of Helsinki shows how a single cough can spread the coronavirus through several aisles in a supermarket and can stay in the air for several minutes before the moisture droplets fall to the ground.
Most people today understand that the coronavirus isn’t airborne itself but that it spreads through the miniature water droplets people breathe, cough, and sneeze out. However, most people are under the impression that these water droplets just fall to the ground at the end of a quick 6-foot-long curve in front of them.
This new video simulation shows us that this is not the case and our respiratory water droplets can stay in the air and spread around for quite a while thanks to different air currents that exist both indoors and outdoors.
This research highlights how important it is to avoid overcrowded indoor spaces and to practice social distancing. And while this is just a single study and just one video simulation, it was actually developed by the four research organizations independently from one another, using the same starting parameters.
Assistant Professor Ville Vuorinen from the Aalto University puts it like this: “Someone infected by the coronavirus, can cough and walk away, but then leave behind extremely small aerosol particles carrying the coronavirus. These particles could then end up in the respiratory tract of others in the vicinity.”
Jussi Sane, chief specialist at the Finnish Institute for Health and Welfare also stressed how important these results are.
“The (institute) recommends that you stay at home if you are unwell and that you maintain physical distance with everyone. The instructions also include coughing into your sleeve or a tissue and taking care of good hand hygiene.”
She also added that “Based on the modeling of the consortium, it is not yet possible to directly issue new recommendations. However, these results are an important part of the whole, and they should be compared with the data from real-life epidemic studies.”
The 30 researchers from these 4 organizations specialize in aerosol physics, fluid dynamics, ventilation, virology, biomedical engineering, and social networks. They used a supercomputer to model the airborne movement of aerosolized particles of 20 micrometers or less (0.0007874 of an inch).
According to the supercomputer “For a dry cough, which is a typical symptom of the current coronavirus, the particle size is typically less than 15 micrometers. Extremely small particles of this size do not sink on the floor, but instead, move along in the air currents or remain floating in the same place. Studies of influenza A have confirmed that the influenza A virus can be found in the smallest particles, which measure less than 5 micrometers.”
Another similar simulation by Belgian and Dutch researchers earlier this month showed how even when you’re outdoors and you’re walking or running behind someone, you can very easily come in contact with the aerosol particles they breathe out.
And while that simulation wasn’t an official study, and even though a lot of the confirmed Covid-19 transmissions seem to have occurred via physical touch and not by breathing in aerosol particles, it’s still vital to be extra careful when you find yourself in enclosed indoor spaces such as supermarkets or when you have to walk behind other people.