Scientists from 32 countries are calling for measures to prevent the spread of the new coronavirus by aerosol droplets.
Addressed to international public health officials, a plea on the importance of fighting Covid-19 airborne transmission will be published in the Clinical Infectious Diseases. The text called “It is Time to Address Airborne Transmission of COVID-19” is signed by 239 scientists from 32 countries, from the most varied fields, such as virology, aerosol physics, flow dynamics, medicine, civil engineering, exposure and epidemiology.
The researchers point to the results of recent studies that show that droplets exhaled by infected people when talking or breathing can reach a distance greater than 1.5 meters.
“Studies by the signatories and other scientists have demonstrated beyond any reasonable doubt that viruses are exhaled in microdroplets small enough to remain aloft in the air and pose a risk of exposure beyond 1 to 2m by an infected person,” said Lidia Morawska, a health and air quality expert and professor at the Queensland University of Technology in Australia, and who is leading the initiative. “At typical indoor air velocities, a 5-micron droplet will travel tens of metres, much greater than the scale of a typical room while settling from a height of 1.5m above the floor.”
According to the researchers, some measures that need to be taken to mitigate the airborne transmission of the virus are: ensuring sufficient and efficient ventilation in public places (offices, schools, hospitals, aged care homes); control ventilation (provide high efficiency air filtration, germicidal ultraviolet lights, and local exhaust); and avoid overcrowding (particularly in public transport and public buildings).
Morawska also points out that several studies have already shown that airborne transmission of Sars-CoV-2 is the most likely explanation for the spread of the disease. “For example, a recent study analysed the data and video records in a restaurant where three separate groups of diners contracted COVID-19, observed no evidence of direct or indirect contact between the three groups, but modelled how the transmission occurred through the air,” she said.
The researchers reinforce that in addition to measures such as hand washing and social distancing, additional precautions are needed in relation to the air – such as the measures mentioned above.