Thanks to the COVID-19 pandemic, governments and health organizations around the world have been putting a strong emphasis on the necessity of wearing masks when out in public. Despite that ubiquitous, worldwide clarion call, however, the reason why this is the case may still be unclear. The below simulation of how the virus that causes COVID-19 may spread as an airborne particle should make that reason abundantly obvious.
Researchers from Aalto University in Finland, the Finnish Meteorological Institute, the VTT Technical Research Centre of Finland, and the University of Helsinki created the simulation (via Futurism). The 30 or so researchers involved specialize in areas of study including virology, biomedical engineering, aerosol physics, fluid dynamics, and social networks. Eskote also participated in the project. They’re a municipal authority for social and health services in Finland and the Finnish Institute for Health and Welfare.
According to an Aalto University post, the supercomputer-generated simulation models “a scenario where a person coughs in an aisle between shelves, like those found in grocery stores.” The simulation shows how aerosol particles—fine, solid particles or liquid droplets that remain suspended in air or another gas—disperse after they’ve been coughed out by a person infected with a virus approximating SARS-CoV-2. That’s the virus that causes COVID-19.
A screenshot from the simulation. Note the yellow and blue colors indicate the height of a given particle. Blue indicates closer proximity to the ground.
Although the researchers divided into different teams that independently modeled the scenario, they all achieved the same preliminary result. The aerosol cloud released by the infected person spreads out into their immediate vicinity. Then, over the course of several minutes, becomes diluted. This finding, according to Aalto University’s post, indicates that “aerosol particles carrying the virus can remain in the air longer than was originally thought.”
“‘Someone infected by the coronavirus can cough and walk away, but then leave behind extremely small aerosol particles carrying the coronavirus,'” Aalto University Assistant Professor Ville Vuorinen told Aalto University News. “‘These particles could then end up in the respiratory tract of others in the vicinity.'”
1/2 A joint project carried out by four Finnish research organisations has studied the transport and spread of coronavirus through the air #coronavirus #COVID19 @IlmaTiede @helsinkiuni @VTTFinland @CSCfi https://t.co/JLZrkSKmZD pic.twitter.com/9elowePRw5
— Aalto University (@AaltoUniversity) April 7, 2020
The researchers say this simulation, and others modeling the spread of viruses through social networks, support the idea that limiting mobility at “nodal points,” or places where a lot of people come into close contact (such as restaurants, shops, buses, trains, etc.), can, in turn, suppress the spread of viruses like SARS-CoV-2.
The cloth face coverings recommended to slow spread of #COVID19 are not surgical masks or N-95 respirators. Those critical supplies must continue to be reserved for healthcare workers and other medical first responders, as recommended by current CDC guidance.
— CDC (@CDCgov) April 3, 2020
Jussi Sane, Chief Specialist at the Finnish Institute for Health and Welfare, told Aalto University News that “it is not yet possible to directly issue new recommendations,” based on this model and ones like it. “However,” Sane adds, “these results are an important part of the whole, and they should be compared with the data from real-life epidemic studies.”
Featured Image: Aalto University