Want to know what is so special about dust?

• Position: Airborne Particles

Chemists isolated 63 unique dust particles from their laboratory--and that was just the beginning. They were testing a new kind of sensor when dust got stuck inside it, and soon discovered that they could measure the composition of single dust particles. In The Journal of Physical Chemistry C, the researchers describe how the discovery could aid the study of respiratory diseases caused by airborne particles.

Most dust is natural in origin, explains chemist James Coe. The 63 particles identified mainly were irregular blobs containing bits of many different ingredients. The most common was organic matter.

"Organic" indicates some type of plant or animal material. Quartz was the second-most common ingredient. Both quartz and organic matter were found in more than half of the dust particles the researchers classified. Man-made chemicals from air pollution, fertilizers, and construction materials also were present in small amounts.

"In that way, a single dust particle is like a snapshot of mankind's impact on the environment," Coe explains.

Scientists have had some difficulty getting precise measurements of dust composition, in part because standard techniques involve...