I lived in Korea for a few years a long time ago and two noticeably different things (from growing up in the US) I saw upon my arrival were many people toting umbrellas in the sun and wearing surgical type face masks as they walked around. Most Americans I know consider ashen/white skin to be unappealing and pay a great deal of attention to getting a tan. Most Koreans seem to think of dark skin as the badge of someone who works on a farm and thus most shy away from exposure to the sun. As far as the face masks, they are typically worn by sick people to halt the spread of germs.
The following is a picture of some Korean cyclists posted on this Korean news page:
The Google language translation page is fun to play with and when I popped the Korean text in it spit out this:
Bike to work every time I talk to is the question, does okay in the air. Air to air dwikkongmuni jotah of a car going, but do more harm anneu concerned to build expressions.
Inappropriate for the city to make cycling in the most serious factors in cities in the world than any of the bad gonggida. The bike is not only in silk. People in the suburbs of the mountains, climbing, walking seoulhyeong chadoreu or write hijapeul. Islam in the face yeoseongman invisible man, even in Seoul, but some of you’re wearing it, and a relatively good mountain air mask, a mask is going.
Obviously some things get lost in translation but I think it is safe to say these folks are worried about air quality issues and not simply making a fashion statement. Anyone from Korea out there feel free to chime in!

I live in Korea at the moment and a lot has to do with what you mentioned. the UV is very high here!
Posted by: todd mullins | 01/26/2012 at 11:04 AM
UV as Todd Mullins mentioned, all sorts of air pollution in urban areas, dusty roads in urban areas in winter with sand used to melt snow, then windswept or blown by vehicles. There's also the notorious "yellow dust" worst in spring, but often present with smog year-round (like daily weather, there are good days and bad days here). If exposed to yellow dust, it can cause severe respiratory infections requiring months of antibiotics, I experienced this twice (2008/2010) and burst a cluster of blood vessels in a lung trying to get rid of it. We do have perfect weather at times, good air quality depending on weather, humidity and precipitation (washes everything out of the sky in the smoggy periods). Plenty of reasons to wear a surgical mask while cycling in Korea. (: Cycling is still excellent here, the mountains, the oceans, the rural areas between, so I wouldn't stop cycling here, just precautions to enjoy it while out riding http://en.wikipedia.org/wiki/Asian_Dust
http://korean-world.blogspot.com/2010/03/yellow-dust-attack-on-korean-serious.html
Posted by: Brian Perić | 01/26/2012 at 12:43 PM
in winter also a quite common picture in germany. breathing really cold air is not the nicest thing u can do to ur lungs
Posted by: mike | 01/29/2012 at 08:26 AM
Matt, a complementary row of biking pics could be made of Americans masked while riding...I'm referring to the decorative face coverings Harley riders use! ;-)
Posted by: Leo Horishny | 01/30/2012 at 08:17 PM
I think the guy doesn't have knowledge about the climate situation of Korea. Korea sees what is called "Yellow Sand Storm" coming from Mongolian Gobi Desert every spring. It blankets the whole Korean Peninsula a long period of time. Even a 50m or less distance can't be seen. It is almost under the shadow of darkness as if an eclipse happens. What is more serious is to cause a 'killing' respiratory system of one's body. In addition, when riding a bike, it also makes skin trouble specially on the face like allergy symptom. Those are a few primary reasons. Dark skin or white skin ? It is absurd. It is not a matter of skin collar. I think he or she, the author, misunderstood what Koreans say or he doesn't have good powers of observation.
Posted by: BikeRidingLover in Korea | 12/30/2012 at 08:54 PM
As men do in the desert, it protects from the dust, from the sun, and your breath creates condensation on the fabric; it keeps your throat, lips and nostrils from drying and helps you from having to drink constantly.
Posted by: newstar | 05/09/2013 at 06:58 AM