Yellow dust swept into Korea on Sunday carrying with it fine dust particles that contain various pollutants, including carcinogens.

Although the yellow dust phenomenon occurs primarily in the spring, the country was hit on Monday by what the Korea Meteorological Administration said was the worst winter yellow dust in five years, resulting in the issuing of the sixth yellow dust warning since 2002.

On Monday morning, the KMA issued a yellow dust warning for Seoul which was subsequently lowered to an advisory in the late afternoon. A yellow dust advisory is issued when an average concentration of more than 400 micrograms per cubic meter of PM10 particulates is expected to last more than two hours. A warning is issued when a PM10 concentration of more than 800 micrograms per cubic meter is predicted. PM10 refers to very fine airborne particles that are 10 micrometers or less in diameter ― less than one-seventh the diameter of a hair strand.

While children, the elderly and the infirm were advised to stay indoors, most Seoulites went about as normal, hoping that the mask that they were wearing would offer some protection.

However, regular cotton masks are ineffective against dust particles measuring 10 micrometers or less. These particles are so fine that when inhaled, they can lodge in the lungs. Doctors have reported a sudden spike in the number of patients coming in with respiratory problems since Monday, attributable to the yellow dust that blanketed Seoul. It seems there is no escaping the yellow dust plague.

Yellow dust originates in the deserts of southern Mongolia and northern China. By the time the dust arrives on the Korean Peninsula, the heavy dust has settled and only the fine particles remain. The danger of these fine dust particles is that as they move through the industrialized regions of China and into Korea, they pick up various pollutants.

The growing desertification of Mongolia and global climate change are expected to exacerbate the yellow dust phenomenon. Experts predict that winter yellow dust may now become routine due to global warming. This means that Koreans will suffer more days of yellow dust. Given the public health hazards that it presents, particularly respiratory and cardiovascular problems, the government should take urgent action on the matter.

Korea has been participating in the reforestation efforts in Mongolia, where 80 percent of the land is undergoing desertification. However, it should step up its efforts to prevent or stop the desertification of Mongolia as the problem is intensifying at an alarming speed.

The government should also seek China’s cooperation in curbing pollution in that country. Experts estimate 30-40 percent of fine dust particles that originate in China move into Korea. Without China’s active involvement, no plan for reducing fine dust particles in Korea will be complete.