Professor Murphy said the Australian Health Protection Principal Committee had recognised that"in a public transport situation,people may choose to wear masks when up close to other people and we recognise that is not an unreasonable thing to do".
![The chief medical officer has backed the voluntary use of face masks on public transport.](https://static.ffx.io/images/$width_300%2C$height_150/t_crop_auto/t_sharpen%2Cq_auto%2Cf_auto/12fabe9b96396109dca11c57d1926d51f0cf832e)
The chief medical officer has backed the voluntary use of face masks on public transport.AAP
The comment is a departure from the previous official advice that there was no benefit in ordinary citizens wearing masks while in public,and comes as new academic research indicated that wearing masks can reduce the risk of transmitting SARS-CoV-2 while asymptomatic.
The Chief Medical Officer warned masks did not provide"a complete protection",echoing the concern of infectious disease experts that they could give wearers a false sense of security. The AHPPC advice remains that Australians must stay home if they are sick.
Professor Murphy said the routine use of face masks in the community was still not recommended,while the rate of community transmission remained low. The AHPPC guidelines state masks should be used if"a person feels unwell and travel by public transport is unavoidable",such as to access emergency medical care.
An academic study published in the peer-reviewed scientific journal BMG Global Health on Friday found masks were 79 per cent effective at curbing transmission - but only before symptoms emerged. It found that masks were not effective after symptoms emerged.
Infectious disease expert Raina MacIntyre,a professor at the UNSW's Kirby Institute,who co-wrote the paper,said that while it was based on data from Chinese families who wore masks at home with a loved one who had COVID-19,its findings were relevant for Australians.
![Professor Raina MacIntyre said face masks are"a low-risk intervention".](https://static.ffx.io/images/$width_300%2C$height_150/t_crop_auto/t_sharpen%2Cq_auto%2Cf_auto/25188c2e30a1107ee17dd65e3ed56cf507b3553d)
Professor Raina MacIntyre said face masks are "a low-risk intervention".Peter Braig
"The tide of evidence and opinion is overwhelming all over the world,"Professor MacIntyre said,calling for masks to be provided on trains,trams and buses and in supermarkets,where"you see people breaking the social distancing requirements all the time".
"Just like how they have hand sanitiser and wipes at the entrance of the supermarket,and you wipe down your trolley,"she said.
"Every country,particularly ones that are going to open up and get things going again,is going to have to consider it ... It's a low-risk intervention and there's a potential benefit."
Public transport experts to lower the chance of transmission as workers return to their offices,after more than 40 countries made them compulsory.
The BMG research paper tracked 460 people from 124 Beijing families where at least one member had tested positive to COVID-19,studying their household hygiene and behaviours during the pandemic,and included those who wore cloth masks,disposable surgical masks and medical-grade N95 masks.
The study found the daily use of disinfectants,window opening,and keeping at least a metre apart were associated with a lower risk of passing on the virus,even in more crowded households. Disinfection was found to be 77 per cent effective at stopping the virus from spreading.
"This study confirms the highest risk of household transmission being prior to symptom onset,but that precautionary[non-pharmaceutical interventions],such as mask use,disinfection and social distancing in households can prevent COVID-19 transmission during the pandemic,"the authors wrote.
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