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Air Quality

◆ What is yellow dust?

Yellow dust refers to dense clouds of fine dust created by winds kicking up fine, dry soil particles from arid regions in northern China and Mongolia, carried eastward by the prevailing wind, and falling back down to ground level.

Yellow dust often occurs between March and May due to low atmospheric pressure and moves eastward on the west wind beyond Korea to Japan and the Pacific Ocean, even reaching as far as North America. Severe yellow dust can obscure the sun to the point it looks light brown in color and cover everything in a layer of dust.

◆ Alert Levels and Instructions for Citizens

Levels and Criteria

Levels and Criteria
Level Criteria
Warning Concentration of 800 ㎍/㎥ or higher expected for 2 or more hours
Emergency Concentration of 1,600 ㎍/㎥ or higher expected for 24 or more hours
Concentration of 2,400 ㎍/㎥ or higher expected for 12 or more hours

Instructions for Citizens


  • Refrain from going outside. When you must go outside, wear masks, protective eyewear, and long-sleeved clothing, depending on your health condition.
  • To help reduce air pollution and extend the lifetime of your automobile, refrain from driving and use public transportation.

<Home and Office>

  • Close the windows to keep out yellow dust. The elderly, the infirm, and people with respiratory conditions should refrain from engaging in outdoor activities.
  • Refrain from engaging in outdoor activities as much as possible. When you must go outside, wear protective eyewear, masks, and long-sleeved clothing. Upon returning home, thoroughly wash your hands and feet and brush your teeth.
  • Drink water frequently and turn on air purifiers and humidifiers to maintain good air quality.
  • Before eating, thoroughly wash and cook vegetables, fruit, fish, and other agricultural or fisheries products that may have been exposed to yellow dust.
  • To prevent secondary contamination, thoroughly wash your hands before handling food or cooking.

<Schools and Other Educational Facilities>

  • Outdoor activities should not be held for preschool and elementary school students. Schools should shorten class hours or close temporarily.
  • Outdoor activities or sports games for middle and high school students should be suspended.

<Livestock Farms and Greenhouses>

  • Livestock out to pasture should be put inside barns quickly to avoid exposure to yellow dust.
  • Close barn doors and windows to minimize the inflow of yellow dust and reduce contact with outside air as much as possible.
  • Fodder or feed piled on the ground or otherwise left uncovered should be covered with plastic or a tent. Close all greenhouse doors and vents.