This archive report was first published on 7 July 2020.
On July 6, 2020, as countries began easing their lockdowns, an international group of 239 scientists sounded the alarm on the airborne threat of COVID-19.
According to a commentary published in the Oxford Academic journal Clinical Infectious Diseases, the researchers urged authorities to recognize that the coronavirus can spread through the air far beyond the two meters (six feet) urged in social distancing guidelines.
The scientists, led by Lidia Morawska of the Queensland University of Technology, recommended new measures to prevent the spread of the virus, including increasing indoor ventilation, installing high-grade air filters and UV lamps, and preventing overcrowding in buildings and transport.
“There is significant potential for inhalation exposure to viruses in microscopic respiratory droplets (microdroplets) at short to medium distances (up to several meters, or room scale),” wrote the authors.
They emphasized that hand washing and social distancing are insufficient to provide protection from virus-carrying respiratory microdroplets released into the air by infected people.
Studies have shown that when an infected person breathes, speaks, coughs, or sneezes, they expel droplets of various sizes, including those that can become suspended in the air as aerosols, remaining aloft for several hours and traveling up to tens of meters.
While the World Health Organization (WHO) advises that the potential for infection from an aerosol occurs mainly in hospitals, some studies suggest that aerosolization and microdroplet transmission can happen in a variety of settings, including bars, restaurants, and choir practices.
“COVID-19 is more likely to be ‘opportunistically’ airborne and therefore poses a risk to people who are in the same room for long periods of time,” said Cath Noakes, a professor of environmental engineering for buildings at the University of Leeds.
The WHO has been criticized for its reluctance to update its advice, with the US Centers for Disease Control and Prevention (CDC) and its European counterpart taking a different stance.
