As a conclusion from their recent study, several Japanese scientists argued that proper ventilation is critical to avoid airborne transmission of coronavirus in indoor spaces.
Pressured by the scientific community, the World Health Organization (WHO) has recently acknowledged the possibility of coronavirus to spread via airborne transmission. The organization explained that transmission through particles known as aerosols “cannot be simply ruled” out in closed, indoor spaces.
Yet the organization remains on its stand that transmission of SARS-CoV-2 is primarily prompted by large droplets produced when coughing and sneezing despite its declaration.
The case, however, is different for Japan.
Japan knew coronavirus could be transmitted via aerosols
For a densely populated country like Japan, recognizing the potential of airborne transmission has helped the number of coronavirus cases and mortality rate low.
“If the WHO recognizes what we did in Japan, then maybe in other parts of the world, they will change (their antiviral procedures),” Professor Shin-ichi Tanabe of Waseda University said, as quoted by CBS.
Among the scientists that lead Japan to acknowledge airborne spread is Makoto Tsubokura. Tsubokura, who operates the Computational Fluid Dynamics lab at Kobe University, conducted his own research concerning the matter and found out that “aerosolized” particles can infect people.
He explained that—although larger droplets easily fall to the ground—in indoor and closed settings with stale and dry air, infected people contaminate the room by leaving “tiny particles that defy gravity” through sneezing, coughing, singing, and even talking. He also argued that these microdroplets could stay in the air for hours and even days.
Proper ventilation is crucial for indoor spaces
Fortunately, he found a solution: proper ventilation.
According to the scientist, the flow of fresh air by opening doors, windows as well as setting up HVAC systems can significantly lower the amount coronavirus lingering in the air.
In an office setting, desk fans can also help dilute the density of the virus. He also recommended partitions that are high enough to avoid the build-up of virus-loaded air.
Tsubokura also tested the possibility of airborne transmission in trains, both with windows closed and opened, and found out that trains with windows open are not as risky as it shows to be.
“[Riding a train] is much safer than a pub, restaurant or gym,” Tanabe of Wasade University seconded.
Tanabe, along with other experts, also echo the same view Tsubokura argued.
In a paper, the team claimed that by proper ventilation and keeping the crowd small, airborne spread in indoor spaces can be prevented. The article is yet to be published in Environment International’s September issue,
Tanabe will also start his research on building the most efficient ventilation system using the world’s fastest Fugaku supercomputer of Japan.