How many different dust particles are you breathing?
In any given room, even the most sterile scientific cleanrooms, there are dust particles in the air and coating every surface. If allowed to go uncleaned, the dust will accumulate to eventually cover every surface. But what exactly is the dust in the air and on our tables and shelves? A chemistry research team at the Ohio State University, using a new kind of sensor, has isolated and measured the composition of unique dust particles in their laboratory.
Led by James Coe, professor of chemistry, the Ohio State University researchers identified 63 dust particles, each containing its own composition of ingredients. They found the most common ingredient of indoor dust was organic matter, originating from either a plant or animal. While not all specifically identified, this matter includes skin particles, dander, pollen, and many others.
The second-most common ingredient is quartz, also the second-most abundant mineral on Earth's crust after feldspar. Both quartz and organic matter were found in over half of all dust particles classified. Other ingredients found were man-made chemicals created from air pollution, fertilizers, and construction materials like gypsum.
The sensor utilized by Coe's research team has a metal mesh, in which particles get stuck. An infrared light is used to pick up the complex details in each dust grain. The mesh helps to separate particles by size which can isolate the ones small enough to enter people's lungs. The potential health care applications are enormous.
The sensor was originally built to create plasmons, mixtures of conducting electrons and photons. These boost the light intensity passing through the metal mesh, letting scientists record, in detail, the infrared light spectrum. Any material inserted in the sensor could be analyzed for its unique signature on the spectrum.
Then dust entered the sensor, clogging the mesh. The scientists then realized the sensor could be effectively used at analyzing airborne dust particles. Coe's students competed to analyze individual dust particles in the air, and found 63 overall. Their research has been published in the recent issue of The Journal of Physical Chemistry C.
Link to published article: http://pubs.acs.org/doi/abs/10.1021/jp205383h