The benefits of face masks have been widely debated amid the coronavirus pandemic, with advice on wearing them varying massively around the world.
Now, a new study claims that wearing face masks does reduce the spread of coronavirus - but only if you don’t move your head.
Researchers form the University of Edinburgh have tested the effectiveness of seven different types of face masks, including homemade versions and medical grade masks.
The analysis revealed that wearing a face covering can reduce the forward distance of an exhaled breath by more than 90%.
Dr Felicity Mehendale, a surgeon at the Centre for Global Health at the University of Edinburgh’s Usher Institute, said: “It was reassuring to see the handmade mask worked just as well as the surgical mask to stop the wearer’s breath flowing directly forwards.
“This suggests that some handmade masks can help to prevent the wearer from infecting the public.”
However, the researchers found that some masks were less effective when your head is turned to the side, with jets of air able to escape.
In particular, heavy breathing and coughing were found to generate intense backwards jets.
The findings indicate that unless your face mask has a tight seal with your face, it could allow any virus-laden particles to escape.
Dr Ignazio Maria Viola, of the University of Edinburgh’s School of Engineering, who co-ordinated the project, said: “I have generally been impressed by the effectiveness of all the face coverings we tested.
“However, we discovered that some face coverings allow the emergence of downward or backward jets that people are not aware of and that could be a major hazard to others around them.”
Dr Mehendale added: “The strong backward jets mean you need to think twice before turning your head if you cough while wearing a mask and be careful if you stand behind or beside someone wearing a mask.”
