Yellow Dust: Cause and Effect

Yellow Dust: Cause and Effect

Yellow Dust is a name given to a seasonal phenomenon in Northeast Asia that comes in the form of string winds that carry sand and dust particles over long distances and cause major health hazards. While this problem is not new, data reveals an increase in frequency and intensity of yellow dust storms. This also means that there is an increase in health hazards connected with this type of storm.

This phenomenon commonly takes place every year in spring when winds carrying dust particles from Mongolia and China sweep across Korea and cause massive disruption in economic activities, farm life and health of the people of the affected area. 2007 was the worst year Shanghai when it recorded air quality of 500 due to yellow dust storm. This was by far the worst record because anything over 300 is considered hazardous, over 200 is also considered unhealthy, 500 was definitely the worst people in China had even seen.

The question that arises is what causes yellow dust storms and where do they normally form? Yellow dust storm is found forming most frequently in East Asian deserts including Taklamakan desert, Gobi desert, and Huanghe river basin. The cause is desertification which means when increased desert dryness occurs, it causes the dust to rise and form a storm which like a twister covers long distances and causes havoc on the health of the people. The other reason that it occurs in spring only is because this is the time when frozen parts of earth melt and produce huge quantities of dust particles. The only known affected areas are China, Korea, Japan and Southeast Asia.

Over the years there has been an increase in yellow dust storms. According to research, several factors have contributed to this increase including "Local atmospheric conditions, topography, stocks of water resources, and global climate" changes. The researchers have also found that increased human activity on land has also increased the frequency of yellow dust storms. "Over-grazing on grassland and depleting forest for lumber production destroy vegetation covers and expose surface soil to strong wind. Over-consumption of water decreases the ground water level and makes the surface soil loose and dry. Global warming effect increases temperature, and defrost soil early in the spring. When precipitation is low, temperature is high, and strong winds blow, YDS probably will occur in sandy areas, transport a long distance, and generate trans-boundary environmental problems."

Yellow dust storm can travel long distances and commonly originates from the Gobi Desert in China. It then travels a large distance to reach Korea and on its way wrecks havoc on the lives on people in both countries and any other affected site. The most common effects of YDS include health problems and poor air quality resulting in visibility issues.

The areas which are affected by dust storm report serious problems with visibility and health. These health problems are not limited to sore throat and asthma though they are the common ones found in regions affected with YDS. When the storm occurs, people are asked to restrict their outdoor activities so they will breathe in the polluted air. The magnitude of impact is directly connected with the intensity of the storm. The more severe ones can cause problems for people going to work and hence can disrupt economic activities. Some of the respiratory problems caused by the YDS can be severe enough to prove fatal. It has been noticed that in areas that encounter yellow dust storms annually, there is an increase in mortality rate.

The effect on farm land is also serious in nature. While the dust itself doesn't harm the farm activities, it is the sulphuric emission and acid rain resulting from the storm that destroy crop by damaging the soil. When soil is affected, animal life is also seriously harmed by the storms especially the cattle. But the effect on sea life is even graver. The economic effects are also especially troublesome as hundreds of flights are cancelled, construction is stopped, manufacturing faces obstacles and general delays crop up in every economic area. (Ai, 2003)

To help us gauge the possible effects of YDS, researches Guo and his colleagues (2005) cite examples of two storm cases and resulting destruction: "a YDS occurred in 1993 in Gansu Province, China directly affected area of 1.1 million square kilometers, caused 85 deaths and 246 injuries, destroyed 4,412 houses, killed 120,000 livestock, and damaged 373,000 hectares of crops land. The direct economic cost of the YDS alone was estimated to be more than 550 million RMB, or about $66 million at current exchange rate. Another YDS in April 2000 in Beijing shut down nearly 60 million square meters construction sites, caused 129 flight delays, and increased road accidents of 20-30% over normal conditions."