'Gross and shocking': COVID-19 face mask test divides social media

A microbiologist has shared the results of a ‘gross and shockingly informative’ experiment in order to demonstrate just how essential face masks are in the ongoing fight against coronavirus — but not everyone is convinced.

Dr Richard Davis took to Twitter on June 27 to post a photo of two rows of agar culture plates, explaining that he’d ‘sneezed, sang, talked and coughed’ on one row of plates while wearing a surgical face mask. He did the same to the other row without wearing a mask.

A microbiologist's COVID-19 face mask test has divided social media. Photo: Twitter/richdavisphd.
A microbiologist's COVID-19 face mask test has divided social media. Photo: Twitter/richdavisphd.

All the plates in the left-hand row marked ‘no mask’ show varying signs of bacterial growth. The plate that was sneezed on is entirely covered in grisly grey growth.

The right-hand ‘masked’ row, however, shows little to no bacterial growth; the plate Dr Davis coughed on twice appears unchanged.

Dr Davis, who is the Clinical Microbiology Lab Director at Providence Sacred Heart in the US state of Washington, explained the findings in his tweet.

“What does a mask do? Blocks respiratory droplets coming from your mouth and throat,” he wrote.

Portrait of young man on the street wearing face protective mask. Young man with closed eyes wear face protective mask and coughing in his arm.
There's growing resistance to wearing masks in the US. Photo: Getty Images.

“Two simple demos: First, I sneezed, sang, talked & coughed toward an agar culture plate with or without a mask. Bacteria colonies show where droplets landed. A mask blocks virtually all of them,” he added.

Dr Davis’s graphic depiction of the effectiveness of face coverings has clearly struck a chord with social media users and his tweet has gone viral — if you’ll pardon the pun — with almost 200k retweets and over 320k likes.

“Wow! Gross and shockingly informative,” wrote one user in the thread.

Dr Davis followed up his initial demo with a second photo showing the importance of adhering to social distancing measures.

“What about keeping your distance? Second demo: I set open bacteria culture plates 2, 4 and 6 feet away and coughed (hard) for ~15s. I repeated this without a mask. As seen by number of bacteria colonies, droplets mostly landed <6 ft, but a mask blocked nearly all of them,” he tweeted.

Once again, there was significantly less bacterial growth on the plates that were coughed on while wearing a mask, regardless of how far Dr Davis was standing.

Face mask fallout

Americans are required to remain 6ft or 1.8 metres away from others and wear a cloth face covering while out in public, according to US Government guidelines.

“Everyone should wear a cloth face cover when they have to go out in public, for example to the grocery store or to pick up other necessities,” it states on the Centres for Disease Control and Prevention website.

Despite these requirements, there’s been growing resistance to masks and social distancing in the US, with two women captured on camera openly flaunting the rules and becoming abusive when asked to adhere to them.

A female shopper at Trader Joes in LA, California was filmed going on an expletive-filled rant after a staff member asked her to either put on a mask or leave.

“You f***ing pigs,” the woman is heard yelling while dramatically dumping her basket.

A woman abused staff who told her to leave a Trader Joe's for not wearing a mask. Photo: Twitter/@ItsRellzWorld
A woman abused staff who told her to leave a Trader Joe's for not wearing a mask. Photo: Twitter/@ItsRellzWorld

Earlier in June, a female customer at New York City Bagel Coffee House shared video of a fellow female customer intentionally coughing on her after she reported her to a staff member for not wearing a mask.

The customer said that the woman “became enraged yelling at me, calling me names, claiming she has COVID antibodies and doesn’t need to wear a mask in public so I should mind my own f’ing business”.

Dr Davis took to the comments section to address the backlash against masks, saying that they should become a ‘normalized act of hygiene’.

“Masks as a political/social litmus test or used to shame those who won't (or disabled folks who truly can't!) wear them is a travesty. We wash hands after using the bathroom & wipe noses on tissues. Masks/face shields need to be just another normalized act of hygiene,” he wrote.

He also responded to questions — and criticism — from Twitter users, many of whom pointed out that his test involved bacteria while COVID-19 is a virus.

“100% true: bacteria are incredibly different from viruses! But since we expect respiratory droplets to be what primarily spreads #COVID19, I exploit the presence of (easily to grow and visualize) bacteria in respiratory droplets, to show where they go,” he wrote.

Others argued that repeating the experiment while wearing different types of face masks — such as disposable paper masks, homemade fabric masks and N95 masks — might cause different results. Dr Davis said that the type of mask wouldn’t change much.

“So COULD you test different masks with this same set up? Yes. Would it be different? Eh. Probably not,” he responded.

As for the song he sang to his agar plates in the demonstration?

“It was ‘Dear Theodosia’ from [the musical] Hamilton, top of my lungs,” he revealed.

Do all Australians need to wear a mask?

According to an infographic published on June 19 by the Australian Government’s Department of Health, not everyone is required to wear a mask.

“If you are well, you do not need to wear a mask where there is low community transmission of COVID-19,” the infographic states.

“However, if you are in a situation where physical distancing is hard, such as on public transport, you may choose to wear one.”

To stay COVID free, the government is encouraging Australians to ‘do the 3’:

1. Wash or sanitise your hands

2. Physical distancing (1.5m)

3. Have the COVIDSafe app

Also, stay at home if you’re unwell and get tested.

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