One of the enduring memories we'll have of 2020 is the sight of faces shielded behind masks. 

Wearing one outside your home has been the law in Melbourne and Mitchell Shire since July 22, as Victoria attempts to tackle a recent surge in cases of COVID-19. And as of midnight Sunday, that will be extended to regional Victorians.

New South Wales residents have also been advised to wear masks on public transport or if they live or work in a virus hotspot.

And on Friday, Woolworths "strongly encouraged" shoppers in NSW, the ACT and hotspot areas of Queensland to wear a mask or face covering in its stores.

While most people are complying with these directives and recommendations, there's a small number who are refusing and loudly spouting myths in the process. Myths that, if allowed to perpetuate unchecked, have the potential to make this already dire situation worse.

Read more: How to have a conversation with someone who refuses to wear a mask.

In an effort to curb the misinformation, Mamamia's daily news podcast, The Quicky, raised five of the most common anti-mask arguments with Sydney physician Dr Brad McKay.

Here are his responses.

'I shouldn't have to wear a mask, because it's my right as a human to do whatever I want.'

"First of all, that's really selfish," Dr McKay said. "We all live in communities and so we all need to protect other people that are around us, and one of the ways that we can protect other people is by wearing a mask. It's not your right to be able to kill other people and to be able to spread infection. 

"It's the same thing when we think of vaccines. We collectively vaccinated as a community—we're collectively immunised—so there's a greater good for the whole population. We need to be thinking about the same thing with masks."

The argument is also flawed from a legal standpoint. 

As Victorian Equal Opportunity and Human Rights Commissioner Kristen Hilton stressed this week:

"The requirement for residents to wear a face mask or covering when leaving the house is a lawful directive that does not violate any rights set out under Victoria’s charter of human rights and responsibilities or any international human rights instruments.

"Shops, businesses and workplaces are able to refuse entry to a person not wearing a mask in order to protect the health of their staff and other customers."

She noted one exception: if you’re unable to wear a face mask or covering because of a disability. 

You can read her full statement here.

'Masks deprive your body of oxygen and weaken your immune system.'

"Masks don't deprive your body of oxygen," Dr McKay said. "Throughout history, we've seen doctors and we've seen nurses wearing surgical masks—people who are performing operations for hours at a time. 

"These are people who are working at the peak of their ability and they're wearing masks every day of their life at work. So, if brain surgeons are able to get through a full day of wearing a mask and they're not getting brain damage at the end of it, then certainly you can wear a mask if you're out on the street for a while."

As for the myth that they weaken your immune system by blocking out microbes? There's no evidence for that: "[A mask] is not going to affect or alter your immune system whatsoever."

Hear Dr Brad McKay's full interview. (Post continues below.)

'We're supposed to leave the masks for the hospitals and medical workers.'

That only applies to high-grade P2, N95 or N99 surgical masks.

"Early on in the pandemic, we really didn't have that many masks available and so we were wanting all of the surgical masks to go to the hospitals," Dr McKay said. "Now we do have more masks available, so you can buy surgical masks around Australia. But even so, we are suggesting for the community to either make your own masks or buy cloth masks online. 

"We definitely want the higher-grade masks for the medical staff...We're wanting to make sure that those people are protected."

'There's no point wearing a mask unless it's surgical grade. Others won't make a difference against the virus.'

"What we've found from recent research is that anything is better than nothing," Dr McKay said.

"You can get masks that are just single layers of cotton, but if you're wearing three layers, that's going to be better than two and [two] is better than one.

"There are some masks that are 12 layers but they're going to be very difficult to breathe through. So we say that the sweet spot is really a three-layered cloth mask."

He said the ideal three-layered mask consists of:

• A water-resistant outer layer (like polyester or polypropylene);
• A middle filter layer ("Some people are using a cotton blend or filter paper or even the wall of a vacuum bag is apparently very good, according to the research.");
• A cotton layer on the inside ("That's to catch some of the moisture droplets from your breath as you're breathing it out.").

"That will be totally sufficient for being out in the community," he said.

'Masks aren't really even making that much of a difference. Look at Melbourne; it's compulsory there and the case numbers are still high.'

Dr McKay points to recent findings that mask-wearing can significantly reduce the incidence of COVID-19 cases.

"We do have that research now to show that it can limit spread," Dr McKay said.

"I think Melbourne's a little bit complicated. It's not just the mask-wearing [that will reduce numbers], but it's also decreasing the amount of people who are circulating and moving around. I think people are in lockdown at the moment and they're doing the best that they can, but there's still a lag between what we do and then seeing those numbers start to drop. 

"We've had a lot of transmission around Melbourne—there's a lot that we haven't realised. And so it will take a long time for those numbers to start to decline.

Feature image: Getty.