Talking loudly in enclosed spaces can release more than 100,000 droplets containing SARS-COV-2 viruses per minute, which can remain in the air for up to 14 minutes. According to the study’s findings, masks are therefore an essential factor in containing the pandemic. The new coronavirus SARS-COV-2 and other respiratory viruses are primarily transmitted through direct contact between people, but also through aerosol clouds. These are tiny droplets that carriers of the virus release into the air through coughing, sneezing, and even talking. Scientists from the National Institutes of Health (NIH) in the United States have now investigated how many droplets infected individuals release into their environment and how long the virus remains in the air.
The study, published in the journal PNAS, involved participants repeating the same sentence in enclosed spaces while the researchers observed how many droplets were released into the air using a sensitive laser. Based on previous studies that had determined how much viral RNA is present in the oral fluid of a person with an average COVID-19 disease course, the scientists estimated that at least 1,000 virus-containing droplets are released per minute of loud speaking. These droplets can remain in the air for up to 14 minutes. However, the study authors note that factors such as air circulation and temperature changes were not taken into account, so the results cannot be directly applied to real-life situations. Nonetheless, the findings show that infected individuals who talk in enclosed spaces are a significant risk factor.
The scientists, led by Valentyn Stadnytskyi, also explain that their estimates are very conservative, and some individuals who deviate significantly from the average can release “well over 100,000 droplets per minute of speaking time.” These study results reinforce the appeal made by some NIH scientists in April to wear masks to slow down the further spread of the pandemic. In conclusion, the study highlights the importance of wearing masks in enclosed spaces and the need to take precautions to prevent the spread of the virus.
