A doctor tested his oxygen levels while wearing six face masks

There is overwhelming evidence that face masks help to slow the spread of coronavirus.

“I think there’s enough evidence to say that the best benefit is for people who have COVID-19 to protect them from giving COVID-19 to other people, but you’re still going to get a benefit from wearing a mask if you don’t have COVID-19,” infectious disease specialist Peter Chin-Hong explains.

Despite this, many people are still concerned about wearing masks. One of the main reasons is a conspiracy theory that suggests masks can lead to heightened levels of carbon dioxide and lower levels of oxygen in the body.

This claim has been disproven by many experts.

To make the point even clearer, Irish general practitioner Maitiu O Tuathail decided to run an experiment by wearing six masks at the same time and testing his oxygen level.

Mask-wearing is mandatory on public transport and in shops in Ireland, but O Tuathail has seen an influx of patients who are concerned about wearing a mask after reading the false claims on social media.

One of his patients suggested that he post a video of himself to counteract these claims and prove that masks are perfectly safe to wear.

O Tuathail filmed himself putting on six masks while hooked up to machine that registers the oxygen level in his body.

O Tuathail explained that he was "getting asked 'Does wearing a face mask lower your oxygen levels' repeatedly by patients today! Based on what they are reading on social media. 

He went on to conclude: "Face coverings / masks don’t reduce your oxygen levels! I managed to get six face masks on + it had no effect on my oxygen levels!"

"That's consistent whether you wear six masks for one minute or for the entire day. The level of oxygen in your blood won't change," O Tuathail told Insider.

However, some people in the comments raised concern that O Tuathail did not wear the mask for very long.

O Tuathail explained that his surgeon friends wear masks for hours on end, and have never had a problem.

"Because oxygen molecules are so tiny, they can permeate through whatever it is you put on your face, no matter how long you leave it on your face for," he explained.

"The first weapon we have in the fight against COVID is social distancing," the doctor said. "But when we can't social distance, our seatbelt, if you want, is a mask or a face covering."