As the Wind Blows.

Germs, like camels, travel upon Sahara Desert sand. But while the camels remain in North Africa, germs take to the air and are wind blown to North America! So says new research from the U.S. Geological Survey (USGS).

The microbes' (microscopic organisms) journey starts when surface winds whip up dust clouds in the Sahara. The dust: clouds filter into the atmosphere and blow across the Atlantic in one week's time. When the dust showers down oil Florida and the Caribbean, stowaway microbes attack coral polyps (sea creatures covered by a hard outer skeleton) and irritate human lungs.

One stowaway, a soil fungus (plant without leaves, flowers, and roots) called Aspergillus sydowii, has killed wide swaths of sea-fan coral in recent years, says USGS coral researcher Eugene Shinn.

Bacteria, viruses, and fungi on the dust may cause respiratory stress above and beyond that caused by dust alone. "Airborne dust is the primary source of allergic stress worldwide," says Shinn. It also absorbs blue light cast by the sun and reflects red light, making for picture-perfect fiery sunsets!