There was this recent study that got published in the peer-reviewed journal Clinical Infectious Diseases which states that researchers have discovered that the fine aerosols exhaled while talking may well seem to play a critical role in the transmission of Covid-19.
Covid-19 and fine aerosols
Researchers learned that fine aerosols (that are less than five micrometers) that are being emitted while either talking or singing, are believed to carry more viral particles in comparison to coarse aerosols that are more than five micrometers. It was also noted that fine respiratory aerosols are likely to play a crucial role in the transmission of Covid-19, most especially in an enclosed environment.
The National University of Singapore conducted the said research as they’ve recruited 22 Covid-19 positive individuals. These patients were requested to give blood, saliva, mid-turbinate, and fomite (phone) swabs, and 30-minute breath samples while they are vocalizing into a Gesundheit-II (a machine that measures viruses in exhaled breath). These activities are said to be done with and without masks up to a couple of visits two days apart.
After gathering the samples, the aerosols were collected in two size fractions: coarse (more than five micrometers) and fine (less than five micrometers).
What scientists found
The research team found out that the Covid-19 positive patients who are already in the course of illness have a high probability of them shedding detectable levels of SARS-CoV-2 RNA in respiratory aerosols. It was highlighted, however, that person-to-person variation in the emission of the virus was pretty high as some of the patients have surprisingly emitted more viruses while they are talking rather than singing.
The result of the study has supplied direct measurements to indicate that other than respiratory droplets, the virus particles that were exhaled during vocalization activities are likely to be significant for the spread of the Covid-19 virus.
With that in mind, the study concluded that the SARS-CoV-2 is evolving toward a more efficient aerosol generation. Further, it did mention that loose-fitting masks only give “modest source control.” The study went on to suggest that until vaccination rates are high, it is necessary to continue layered controls and tight-fitting masks and respirators are highly recommended.