Asked by: Edward Seymour, Hove
The wearing of face masks has become the norm in Japan, even making it as far as the couture catwalks. But what many people in the West don’t realise is that they’re usually worn by a person who has the cold or flu to protect others, rather than to protect the wearer. This is also true of the face masks worn by dentists and surgeons, which are designed to stop the wearer spreading their germs to the patient.
However, by providing a barrier, the masks are also effective at protecting the wearer from airborne viruses. They likely add further protection by keeping the mucous membranes in the nose and throat moist, helping our airways to expel germs, and they’ve also been shown to protect hay fever sufferers from pollen.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun facts.