Moon Dust Madness!

Quartz, the main cause of silicosis, is not chemically poisonous: "You could eat it and not get sick," he continues. "But when quartz is freshly ground into dust particles smaller than 10 microns (for comparison, a human hair is 50+ microns wide) and breathed into the lungs, they can embed themselves deeply into the tiny alveolar sacs and ducts where oxygen and carbon dioxide gases are exchanged." There, the lungs cannot clear out the dust by mucous or coughing. Moreover, the immune system's white blood cells commit suicide when they try to engulf the sharp-edged particles to carry them away in the bloodstream. In the acute form of silicosis, the lungs can fill with proteins from the blood, "and it's as if the victim slowly suffocates" from a pneumonia-like condition.

Microscopic images of Moon Dust

Lunar dust, being a compound of silicon as is quartz, is (to our current knowledge) also not poisonous. But like the quartz dust in the Hawk's Nest Tunnel, it is extremely fine and abrasive, almost like powdered glass. Astronauts on several Apollo moon missions found that it clung to everything and was almost impossible to remove; once tracked inside the Lunar Moon Module, some of it easily became airborne, irritating lungs and eyes.

Martian dust could be even worse. It's not only a mechanical irritant but also perhaps a chemical poison. Mars is red because its surface is largely composed of iron oxide (rust) and oxides of other minerals. Some scientists suspect that the dusty soil on Mars may be such a strong oxidizer that it burns any organic compound such as plastics, rubber or human skin as viciously as undiluted lye or laundry bleach.

"If you get Martian soil on your skin, it will leave burn marks," believes University of Colorado engineering professor Stein Sture, who studies granular materials like Moon - and Mars-dirt for NASA. Because no soil samples have ever been returned from Mars, "we don't know for sure how strong it is, but it could be pretty vicious."