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EPA \ TAQMN \ Dust Storm \ Global Impact

Global Impact

After large dust storm occur in winter and spring, the sand blown up causes the atmosphere to be filled with large amounts of sand, obstructing sunlight and at time reducing visibility to zero, which is why super dust storm are also called black storms. According to studies, there have been 48 super dust storm in the northwestern region of China in the past 40 years, causing 11 deaths and great damage to the lives and agriculture industry of the people. Taiwan is not a main region of transport after super dust storm occur in China, only under special weather conditions will it lead to poor air quality. The mud rain phenomena of March 12th and 13th of 1995 are the most severe cases.

Dust storm that are transported several thousand kilometers to other regions often affect local visibility and causes suspended particles in the atmosphere to increase, affecting local air quality. The duration and scale of affect is usually determined by the scale and duration of the original dust storm coupled with whether local weather conditions are advantageous to the transportation or settlement of sand. According to past records, visibility may be affected for a few hours or muddy rain phenomenons can occur when duration is a week. In 1993 when Korea was affected by a dust storm, the micro particle density in the air was 3 times the normal amount, visibility was less than 1 kilometer, and atmospheric micro particle density reached 1105 μg /meters squared. Therefore, countries that are affected by dust storm monitor weather and air quality to under the affected conditions of local regions, then retroactively study the time of occurence and scale of the original dust storm. Sand particles block the respiratory pores of plants to obstruct photosynthesis, and during periods of dust storm symptoms of respiratory diseases and allergies increase. If during transport man-made pollutants are combined with dust storm, the effect on human health is more severe. Those who wear contact lenses are advised to remove them due to possibility of irritation.

The dust storm of east Asia raise the possibilities of poor visibility and increased micro particle density in the air which affect Taiwan's agriculture, traffic, and air quality. At the most extreme, on March 12th of 1995 muddy rain was recorded in Taiwan's north region. From analyzing the PM10 samples of the Keelung and Hsichih monitoring stations, the samples from the 12th when compared to samples from the 26th and 27th of the same year had greatly increased amounts of Al and Ca, with the ratio of alkaline gold and alkaline earth elements showing increases. This phenomenon is similar to the characteristics of foreign east Asian dust storm studies, as these dust storm contain rich amounts of Al and Ca, proving that the sharp increase in PM10 density could be from east Asian dust storm. Furthermore, micro particles collected from PM10 sample filter paper in multiple stations showed a yellow brown color, which is highly different from the gray black particles during non dust storm periods. It is evident that the source of PM10 pollution is different from the usual source.

last update : 2017/07/31

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