Did you know that you can check the dust level in Seoul with the Namsan Tower light?
As spring breeze starts to blow in South Korea, you will find many people wearing masks to prevent yellow dust and ultra-fine particles from China. Sometimes you may see a yellow dust storm sweeping across the buildings. However, it is difficult to notice the ultra-fine particulates with the naked eye.
But, you don’t have to worry. Namsan Tower will tell you whether or not you should stay inside that day. Since May 2011, the Seoul Metropolitan Government has changed the light of the Namsan Tower to blue whenever the fine dust density level – particles 10 micrometers or less in diameter – is below 45 micro-grams per cubic meter. In other words, you can go outside and enjoy fresh air when the tower shines blue.
Last year, Seoul decided to change the light of the tower to bright red at the same time it issues ultra-fine dust alerts to public. The alerts are made if the fine dust concentration levels stay over the 120 micro-grams-per-cubic meter-thresholds for more than two hours.
If you do not live close enough to see the light, follow @yellowdust on twitter, an automatic machine that tweets the air quality in Seoul every hour.