Scientists vacuum up the data on dust

Last Updated: Monday, February 22, 2010 - 10:01

San Diego: While most people give it the brushoff, a panel of scientists gathered Friday to focus on dust. Dust in the air. Dust in the oceans. Dust in your lungs. Good dust. Bad dust. And not a can of Pledge in sight.

The scene, a conference room at the annual meeting of the American Association for the Advancement of Science in usually sunny Southern California, the land where recent wildfires filled the air with smoke and dust.

Some researchers found fault with dust — "geotoxicology" Geoffrey S. Plumlee of the U.S. Geological Survey calls it.

But turns out dust can fertilize land and the ocean, aiding some types of sea life.

While it seems climate changes affect the amount of dust in the air, the effect of dust on climate change is less clear.

And historical studies indicate that ice ages were surprisingly dusty.

On the down side, Plumlee reports that the air you breathe can have a "breathtaking" array of particles in it.

The soil fungus that causes valley fever in the Southwest, for example, is carried in windblown dust. And increases in dust in the air lead to higher rates of hospital admissions for things like asthma, he added.

Other bad effects can range from increased heart attack risk to cancers and scarring of the lungs.

Most public health focus has been on particulates from human sources, such as from combustion of fossil fuels, but there is increasing attention to potential health effects from dust from such sources as volcanic ash or of smoke and ash from wildfires, he said.

Daniel R. Muhs, also from the Geological Survey, disclosed that studies of ocean sediments and Antarctic ice shows that ice ages were even dustier than today.
Glaciers are major producers of dust by grinding over rocks, he explained. Muhs pointed out that water flowing from beneath glaciers is often milky from the dust enclosed, not clear. In addition, he said, glacial periods were drier and thus places like Africa had less vegetation and the wind could stir up more dust.
Speaking of African dust, it may be beneficial by fertilizing regions such as the Amazon basin, said Oliver Chadwick of the University of California, Santa Barbara.

Even Hawaii, one of the world`s least dusty places, has forests fertilized by blown-in dust, he said.

Bureau Report



First Published: Monday, February 22, 2010 - 10:01

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