Coughing and sneezing may not be the only way individuals transmit infectious pathogens including novel coronaviruses that kill each other. Talking also has the potential to launch thousands of tiny aerosol particles so small that they remain suspended in the air for eight to 14 minutes, the latest research says.
Research published in Proceedings of the National Academy of Sciences may explain how individuals with mild or impossible symptoms infect other people they come to nearby places including offices, homes, cruises, and other confined spaces.
However, this finding needs to be replicated in real world circumstances. Researchers do not really understand the amount of virus needed to be transmitted from one person to another to cause infection.
The finding that the corona virus can be transmitted through talking to each other can strengthen cases for wearing PPE such as masks and taking other precautions in the environment to reduce the spread of COVID-19.
The researchers used an intense laser beam to visualize the bursts of speech droplets produced during repeated spoken phrases. They then obtained quantitative estimates for the number and size of speech droplets that remain on the air. The participants were asked to speak in the open end of a cardboard box and the researchers illuminated the inside with a green laser and tracked the bursts of droplets the person produced while speaking.
These findings reveal the following:
- Laser scanning records about 2,600 tiny droplets per second while someone is talking
- Speaking louder can produce greater droplets as well as this larger number of droplets
- Just one minute of loud talking can produce at least 1,000 speech drops that contain a virus
- These drops shrink after dehydration as soon as they leave someone’s mouth, but they float in the air for about eight to 14 minutes.
Researchers do not yet understand whether all the speech, sneezing, and cough drops that carry pathogens are equally contagious or if a certain amount of a deadly novel coronavirus needs to be transmitted so that someone becomes ill with it.
Based on this and other evidence, it would be wise to avoid face-to-face conversations with other people unless you are far apart and in a well-ventilated room, including outdoors, “Linsey Marr, a professor of civil and environmental engineering at Virginia Tech told the New York Times.