Pollution index (Good, Moderate, Unhealthy, or Very Unhealthy)?
Unhealthy, but Seoul is rapidly becoming a green city. Most, if not all of the buses run on LPG. - Sep 2009
It has improved a lot in the last 10 years. But still a problem like most major cities around the world. - Jul 2008
Bad compared to the U.S., but moderate compared to other polluted Asian cities. Not nearly as bad as I'd been led to expect. - May 2008