The Woolcock Institute of Medical Research

With Brisbane in lockdown due to COVID-19 clusters that spread from the healthcare system, timely research has just come out showing the need for better mask-wearing protocols and ventilation for frontline staff .

Professors Euan Tovey from the Woolcock Institute of Medical Research and Guy Marks from The University of New South Wales were key researchers in this ground-breaking international study published in the journal Anaesthesia.

The researchers measured the numbers and size of particles of respiratory fluid produced when people cough, shout and breathe deeply and compared this to the particles produced with so-called 'aerosol generating' respiratory therapies. 

The researchers issue a sober warning.

"Coughing produced over 100-fold more of the small aerosol-sized particles than quiet breathing, while the therapies only produced two to eight times more, yet the latter mandate the use of greater respiratory protection. These small particles can more easily leak around the edges of surgical masks and staff safety can only be increased by more widespread use of specialised tight-fitting respirators and increased indoor ventilation," says Professor Tovey. 

The findings could in part explain why staff working on wards who wear only surgical masks have around two to three times higher rates of infection and hospitalisation than those working in ICUs, where more personal protective equipment is used.

"The study also has implications beyond hospitals," says Professor Marks. "The [findings] reinforce the importance of maintaining social distance, having excellent ventilation in buildings and transport, being outside where possible and using effective masks both to protect from breathing in virus and reducing the amount of virus they spread when breathing out."

Find out more

• Australian researchers find COVID-19 aerosol spread that puts some healthcare workers at risk over others, ABC news 31 March 2021
• Read the full research paper The effect of respiratory activity, non-invasive respiratory support and facemasks on aerosol generation and its relevance to COVID-19.