Les Japonais ne portent pas des masques de chirurgien que pour des raisons de santé

http://en.rocketnews24.com/2014/02/21/why-do-japanese-people-wear-surgical-masks-its-not-always-for-health-reasons/

“She puts on a mask and sticks headphones in her ears so that people won’t bother her. It makes it harder for them to start talking to her.”

"“When we deal with others, we have to judge whether to do things like smile or show anger,” he explains. “By wearing a mask, you can prevent having to do that. The trend of wearing a mask to prevent directly dealing with other may have roots in the current youth culture in which many of them are more accustomed to communicating indirectly through email and social media.”

"an increasing number of people are using masks because of their desire for warmth.
Having your glasses steam up is a small price to pay to keep your lips warm enough that you can move them."

"Even women whose livelihood doesn’t depend on looking their best at all times are finding masks to be a handy for those times when they need to dash out to run errands and don’t feel like spending a half-hour putting on blush and lipstick first."