A recent study by researchers at the National Institutes of Health says particles of the coronavirus released by an infected person while talking can remain in the air for 8 to 14 minutes, a warning sign that airborne transmission might be more contagious than previously anticipated.
The scientists behind the study said, while it has been long accepted that coughing and sneezing can transmit respiratory viruses through droplets, It is less widely known that normal speaking also produces thousands of oral fluid droplets with a broad size distribution.
The research, published last week in an edition of the peer-reviewed Proceedings of the National Academy of Sciences, highlighted that, “There is a substantial probability that normal speaking causes airborne virus transmission in confined environments.”
“Speech droplets generated by asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasingly considered to be a likely mode of disease transmission,” the study reads.
It noted that while COVID-19 is less deadly than SARS, it is far more easily transmitted, and scientists are still working to understand the extent to which it can be spread and how long it can survive.
“This information has huge ramifications for how we interact with one another and what kinds of spaces and activities are considered safe,” it said.
The three paged study, titled “The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission” highlighted that in a closed, stagnant air environment, they (droplets) disappear within 8 to 14 minutes.
“These observations confirm that there is a substantial probability that normal speaking causes airborne virus transmission in confined environments,” the report said.
Findings from the study show that the velocity and the duration droplets stay in the air are also dependent on a range of factors, including the volume of the talker, their age, and how dry the speaker’s mouth is.
“Speech droplets generated by asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasingly considered to be a likely mode of disease transmission,” the study found.
Also, it says, highly sensitive laser light scattering observations revealed that loud speech can emit thousands of oral fluid droplets per second.
“Public transport and rooms with poor ventilation are considered high-risk areas for this kind of transmission,” the study noted.
Meanwhile, arrays of scientific studies have posited new findings and sometimes varying findings on the fast-spreading coronavirus.
For instance, some scientists are of the view that the virus could survive for up to three hours in the air “post aerosolization”, while a team of researchers at the Academy of Military Medical Sciences in Beijing found that droplets can travel as far as 13 feet.
The coronavirus disease has infected more than 4.8 million people worldwide, with more than 300,000 fatalities, so far.