If I want to know the current status of the air, I can choose between this site meant for US military (the default one in Yongsan is in the middle of Seoul), and this Korean weather site and choose the listings for 관악산 (the sensor for the Seoul area). One or the other is often down. Obviously, readings for a huge area aren’t always accurate. Somebody’s air conditioner in my building is spewing smoke and making a lot of noise right now. I don’t know why they’d use an air conditioner now either, since it is only 20 °C outside.
This made me think of air quality for the Olympics. Beijing has promised the air will be cleaner during the Olympic period. Normally, Beijing air is one of the more polluted places within China. As I write this, their air has 75 ppm of pollutants. I was surprised to discover the cleanest air in a Chinese city happens to be Lhasa. For the past few days, pollutants have made up 18 parts per million of the air. The sensor for Seoul is currently reporting 7ppm, but it certainly doesn’t smell like that.