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Scientists explore mysteries of dust

WASHINGTON — Dust, dust, dust. It's everywhere, burrowing under beds, piling up on windowsills, clogging machinery, irritating eyes, noses and lungs. It soars thousands of miles over continents and oceans, sometimes obliterating the sky.

Enormous masses of the stuff — fine grains of soil, sand, smoke, soot, sea salt and other tiny particles, both seen and unseen — pervade Earth's air, land and water.

Now scientists are beginning to have new respect for the way dust alters the environment and affects the health of people, animals and plants. As climate change raises temperatures and forests are cleared for agriculture and other development, the amount of dust swirling through the Earth's atmosphere is expected to grow. The likely effect is unknown.

Unlike greenhouse gases, most airborne dust particles turn back the sun's rays and thus cool the planet.

"Environmental scientists are increasingly recognizing dust as both a major environmental driver and a source of uncertainty for climate models," said Jason Field, a soil researcher at the University of Arizona in Tucson, who co-wrote a paper, "The Ecology of Dust," that was published in the latest edition of the journal Frontiers of Ecology and Environment.

By blackening snow and ice, dust even may have contributed to the end of the Ice Age 10,000 years ago, Karen Kohfeld, an environmental scientist at Queens College in Flushing, N.Y., wrote in Advances in Science, a publication of the Royal Society of London.

The amount of dust traveling through the atmosphere is huge, Kohfeld said.

"Although these individual particles are often invisible to the naked eye, billions of tons of material are transported every year" through the air, she said. "Some of these transport events are even visible from space."

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