At first glance, dust storms do not seem very fascinating. Winds pick up fine particles from the ground, and then the air becomes thick with dust. What is interesting, though, is that dust storms can travel across the ocean, sometimes from continent to continent. Such dust storms are worth investigating.

In April of this year, a dust storm that originated in China and Mongolia took a six-day journey across more than ten thousand kilometers of sea and open land to Arizona in the United States. The cloud was so dense that it seemed as if the sun were setting early. At least one person thought a volcano had erupted.

Although traveling dust storms are nothing new, the dust now often contains chemical or metallic substances that contribute to respiratory illnesses and damage the environment. At present, a group of researchers in Asia is studying aerosol particles and their effects on the environment—and they have plenty of dust to work with.

Dust storms are one of the repercussions of humans messing around with Mother Nature. Although they are a natural phenomenon, dust storms have been occurring more often, at shorter intervals, and with greater force in recent years, and human activity is the cause.

It is a fact that excessive herding of animals and exploitation of grasslands are responsible for the majority of dust storms. This means that dust storms are largely a result of human actions; in other words, they are controllable.

We seem to think, however, that economic development and preservation of the environment cannot go hand in hand. For most countries, economic development comes first, at the expense of the environment. It is high time everyone came to grips with the consequences of overusing the earth's resources, including the misuse of land in the pursuit of economic wealth.

乍看之下，沙塵暴似乎不怎么引人注意。地面的細沙被風卷起，空氣中便充滿厚厚的灰塵。但有趣的是，沙塵暴能穿洋渡海，有時還能橫越大洲。這樣的沙塵暴值得我們去好好研究一下。

今年四月，源自中國大陸及蒙古內陸的沙塵暴，在六天中跨越了一萬多公里的海洋與空曠陸地，最后到達美國亞利桑那州。陰云密布，就象太陽將提早要下山，有人居然以為是火山爆發(fā)了。

雖然移動的沙塵暴沒什么稀奇，但現(xiàn)在那些沙塵通常含有引起呼吸道疾病和破壞環(huán)境的化學或金屬物質。現(xiàn)在亞洲有一批研究人員正在研究懸浮顆粒及其對環(huán)境的影響──他們要研究的沙塵可多著呢！

沙塵暴就是人類任意破壞大自然，所造成的影響之一。沙塵暴雖是自然現(xiàn)象，但是近年來發(fā)生的頻率卻逐漸增加，間隔的時間也愈來愈短，破壞力更強大了，人的活動是罪魁禍首。

事實上，沙塵暴形成的主要原因是過度放牧及濫墾草原，這表明沙塵暴大多是人的活動所導致，也就是說，它們是可加以控制的。

不過，我們似乎認為經(jīng)濟發(fā)展與環(huán)境保護無法同時兼顧。對大部分國家來說，經(jīng)濟發(fā)展是第一位的，為此可以不惜犧牲環(huán)境。然而，我們已過度使用了地球的資源，包括為了追求經(jīng)濟繁榮而濫用的土地，如今該是我們認真面對這個后果的時候了。