Covid-19: Aerosol expert in despair at inaction

Aerosol scientist Lidia Morawska says she is despairing at Australia’s failure to urgently address poor ventilation as a primary cause of the spread of Covid-19.

Aerosol physicist Lidia Morawska from the Queensland University of Technology. Picture: Lyndon Mechielsen

Aerosol scientist Lidia Morawska says she is despairing at Australia’s failure to urgently address poor ventilation as a primary cause of the spread of Covid-19 amid repeated lockdowns following airborne transmission in indoor spaces.

Professor Morawska, the director of the International Laboratory for Air Quality and Health at Queensland University of Technology, said action to impose ventilation standards would be the single most effective public health measure Australia could take to curb the virus.

“Physical distancing lowers the concentration of the virus that people are exposed to, but does not prevent inhalation of the virus present in the air of enclosed spaces,” she said.

“Masks should be used to minimise the risk of infection for high-risk workers at international borders, health and aged care (but) they form the last line of defence among control measures against community transmission and lower the risk in the community only during periods of mandated mask-wearing.

“Hand sanitising is helpful but does not protect the population from the virus in the air.

“Cleaning surfaces provides only a marginal contribution to respiratory infection control because the virus is predominantly in the air.”

Professor Morawska said governments could markedly reduce the risk of outbreaks starting and spreading by putting in place mitigation measures to minimise infections contracted in public indoor spaces and communicating the risk to the public.

“In this critical period as we wait for high levels of community vaccination, addressing ventilation could make the difference between recurring lockdowns or enjoying a Covid-free life for Australians.”

In May, Professor Morawska led 40 international aerosol scientists in calling for the introduction of ventilation standards in a public health measure that was described as being akin to the transformation of sanitation infrastructure in Britain in the 19th century.

Her article in the journal Science prompted attention from within federal cabinet but as yet no measures have been taken to improve ventilation standards.

Professor Morawska said simple changes could dramatically decrease the risk of transmission of Covid-19 in indoor spaces such as simply opening windows or doors of restaurants.

Where there were no windows, air purifiers could be used, and carbon dioxide meters should be routinely used to monitor air quality.

“In Australia, like in many other countries, there have been numerous petitions, briefings and communication on this matter by scores of scientists, medical professionals and engineers to the respective bodies of the government. They have yet to be translated into action and Australians continue to be exposed to the virus present in the air,” Professor Morawska said.

The World Health Organisation now recognises airborne transmission of Covid-19 after initially denying SARS-CoV-2 was an airborne pathogen.

“If we want to safely open society, we must take measures to adequately ventilate public indoor spaces to deliver the freedom Australians seek,” she said.