Crowded places with poor ventilation are especially dangerous for the transmission of the coronavirus, according to a new study. The study, published on Monday, April 27th in the journal Nature Researcher, was conducted in two hospitals in Wuhan, China.
According to the researchers, not only is the virus easily-transmissible through the tiny airborne water droplets we breathe out when we cough, sneeze, and talk, but said aerosol particles have been found floating for a long time in public toilets and other large crowded places in the hospital where the staff take off their protective gear.
The question of whether the Covid-19 virus spreads more through aerosol transmission or by coming in contact with infected surfaces has been widely debated over the past several months. According to the World Health Organization, the risk is limited to only specific circumstances based on previous research of thousands of cases in China.
However, as the total number of infected people has passed over 3 million people, new data seems to suggest that infections via aerosol transmission may be more common than we thought.
What may have been at the center of the division and confusion is that people actually release two types of airborne water droplets when they speak, cough, or sneeze. According to the recent study, larger drops fall on the ground fairly quickly as they are heavier and more subjected to gravity. Smaller water droplets, however, can hang in the air and float on air currents for hours.
The research group is headed by Ke Lan of the Wuhan University. The way they performed their tests was that they set up aerosol spray traps in two hospitals in the town where the pandemic started. The aerosols simulated the tiny water droplets released by humans by even just breathing out. Said droplets were then discovered still lingering in the air of toilets, patients wards, corridors, and other crowded places for hours.
Most importantly, the water droplets were most common in poorly-ventilated rooms and in rooms where people didn’t wear protective gear. These results strongly reinforce the importance of not only face masks and protective gear but that of adequate room ventilation as well.