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，沙尘暴似乎不怎么引人注意。地面的细沙被风卷起，空气中便充满厚厚的灰尘。但有趣的是，沙尘暴能穿洋渡海，有时还能横越大洲。这样的沙尘暴值得我们去好好研究一下。

今年四月，源自中国大陆及蒙古内陆的沙尘暴，在六天中跨越了一万多公里的海洋与空旷陆地，最后到达美国亚利桑那州。阴云密布，就象太阳将提早要下山，有人居然以为是火山爆发了。

虽然移动的沙尘暴没什么稀奇，但现在那些沙尘通常含有引起呼吸道疾病和破坏环境的化学或金属物质。现在亚洲有一批研究人员正在研究悬浮颗粒及其对环境的影响──他们要研究的沙尘可多着呢！

沙尘暴就是人类任意破坏大自然，所造成的影响之一。沙尘暴虽是自然现象，但是近年来发生的频率却逐渐增加，间隔的时间也愈来愈短，破坏力更强大了，人的活动是罪魁祸首。

事实上，沙尘暴形成的主要原因是过度放牧及滥垦草原，这表明沙尘暴大多是人的活动所导致，也就是说，它们是可加以控制的。

不过，我们似乎认为经济发展与环境保护无法同时兼顾。对大部分国家来说，经济发展是第一位的，为此可以不惜牺牲环境。然而，我们已过度使用了地球的资源，包括为了追求经济繁荣而滥用的土地，如今该是我们认真面对这个后果的时候了。