Across Europe, masks and covers are becoming commonplace as COVID-19 restrictions ease, but health officials continue to ask for caution.
World Health Organization (WHO) advice has remained consistent in recent weeks, recommending masks mainly for medical personnel.
But they say "currently there is insufficient evidence for or against the use of masks (medical or otherwise) for healthy individuals throughout the community ".
The main recommendation is to save them for people who have symptoms of coronavirus or are taking care of a suspected case.
For countries that currently consider wearing masks more generally, WHO advises policymakers to apply a "risk-based approach".
But on social media, rumors have quickly spread that wearing masks can cause other medical problems related to the respiratory system.
An article in a Nigerian newspaper suggested that prolonged use of face masks causes hypoxia – a condition in which body tissues suffer from oxygen.
Another chart spread across Europe on Facebook, arguing that prolonged use of masks can cause hypercapnia – another condition due to excess carbon dioxide (CO2) in the blood.
But both claims are of origin and cited inappropriately.
A report on social media misinformation in the European Union found that messages "often focus on trying to undermine confidence in institutions and governments"
& # 39; No impact on CO2 levels in ordinary individuals & # 39;
The WHO recognized in its interim guidelines on the use of masks, released in April, that there were disadvantages to wearing a mask, including "breathing difficulties" and a "dependence" on facial coatings.
But in a statement to Euronews, the WHO Europe office said that concerns about carbon dioxide intake are doubtful.
"A buildup of CO2 is one aspect of wearing a mask that many people find a little uncomfortable, but wearing a homemade or regular surgical mask is unlikely to cause hypercapnia," said a spokesman.
The WHO said that some medical teams may face a problem when using "tight respirators" as opposed to cotton or fabric face masks.
It was also noted that recommending the use of face masks could restrict their availability to medical professionals worldwide.
"It is possible that the use of masks, with unclear benefits, can create a false sense of security in the user, leading to the diminished practice of recognized preventive measures, such as physical distance and hand hygiene".
Global health officials stressed that masks alone do not provide adequate protection and other health measures must also be adopted.
Nina Shapiro, a professor at the UCLA School of Medicine, told Euronews that the coverings "have no impact on CO2 levels in ordinary individuals".
"(N95 masks) have been used for fire / smoke protection and for construction workers for many years".
"They are extremely uncomfortable and very aggressive to the skin, but the notion that thousands of workers are becoming hypoxic and / or hypercapnic is unfounded."
Shapiro explains that this is because the respirator's carbon dioxide particles are so small that they pass through the mask material, unlike the larger particles of the coronavirus.
Masks have a substantial impact on transmission & # 39;
Other online concerns have focused on wearing a mask while exercising, but medical experts say cloth masks are more recommended for that use.
"They reduce the increase in the spread of respiratory droplets known for efforts," Shapiro told Euronews.
"Each of these droplets can carry COVID-19 particles – all the more reason to wear a mask."
Breathing in excess of carbon dioxide can be dangerous for the human body, especially for people with pre-existing respiratory illnesses, and face mask warnings are also in effect for children under two years of age and anyone who cannot remove the mask without assistance.
However, medical guidelines indicate that other citizens are at little or no risk of breathing unhealthy amounts of carbon dioxide wearing surgical clothing or masks.
Scientists at Arizona State University also said that if 80% of people used one, it could reduce mortality somewhere between 24 to 65%.
In April, the British Medical Journal also wrote that it masks “could have a substantial impact on transmission, with a relatively small impact on social and economic life ”.
"Looks like much of Europe is on the same page"says Euronews political editor Darren McCaffrey.
"The political positioning in Europe is moving towards making it mandatory to cover the face and mouth – mainly in public transport and in crowded places".
"It seems that governments are also advising us to wear face masks; not just because they can protect our health, but also because they have concluded that it will make us feel safer when we try to return to a sense of normalcy."
Nina Shapiro added that a significant reason for wearing masks is that citizens can spread the virus without knowing it.
"Coronavirus usually goes through a variable period of stage" asymptomatic "or" pre-symptomatic "for up to several days".
The World Health Organization says it is actively studying "rapidly evolving" science and continues to update guidance.