Dust is truly ubiquitous on our planet. In oceans and on land, in cities and in the wildest of terrains, in palaces and hovels, it is a constant. We accept it in our daily lives as an inevitable nuisance that must be collected and disposed of. It irritates our eyes and lungs, it offends our sense of hygiene; it seems the antithesis to the life-bringing properties of rain. But unlike rain, most of us ignore the composition of dust, where it comes from, and what benefits or destructive qualities it might have. We invariably cannot even define it properly, either in size or weight. We think of it as covering the floors of our homes without realizing how high in our atmosphere dust exists. We dismiss dust, and in that, we are wrong.
If you look up “Dust” in Wikipedia, and who of us has not, you will find a mediocre article somewhat below their normal standards. It begins by defining dust as “particles in the atmosphere” but later mentions that there are large clouds of dust in outer space. Hey guys, that is not “in the atmosphere.” Clearly their first definition is too limited.
Often times when I read a Wikipedia article, I pursue the words written in blue that interest me. Words in blue mean they have their own articles. So naturally, my “dust” journey linked me to “cosmic dust” and led me to find out that there is an enormous amount of this stuff around. It can form planets and it can radiate light—for example, when it forms the luminous tails of comets. About 40,000 tons of the stuff lands on Earth every year because our gravitational pull attracts dust. “Stardust” sounds romantic; but in fact, it makes us a dusty place.
I want answers to all the dust questions worth asking—like, what color is dust? The answer is very vague. When you get dust on a black surface, it can look sandy; while on a sandy-colored surface, it can look black. Coupling this with the ability of dust to radiate and reflect light, I take it to mean that you can have dust of any color, depending on the substance it deteriorates from. The largest organ of the human body, a white/pink/brown-colored organic substance we refer to as our skin, disintegrates into a white/grey-colored skin dust. Apparently we create the majority of the dust in our homes from discarding dead skin cells wherever we go. Outside our homes, most of the dust on our planet comes from sand. I think of sand as a type of dust, but maybe there is a separate definition specifically excluding sand which I have not found. I do know, because the United Nations Environment Programme (UNEP) tells me, that dust can be carried thousands of miles by strong winds. So we can get Saharan dust in New York while Gobi desert dust can get to North America by winds going the other way. My daughter, an environmental geo-chemist (I do not know what that means either!), tells me that dust can help control the temperature of the planet because dust landing on the ocean will reflect back the heat of the sun. But desert dust can also be a factor in preventing rainfall by inhibiting the formation of raindrops, and so the deserts may get dustier because of the dust they produce.
There seems to be no agreement as to what exactly constitutes the size of dust. I have read that some dust particles are more than one-hundred microns while others are less than five. (A micron is a millionth of a meter.) I still have not found an article that defines the limits of an object’s weight which qualifies it to be called dust. What is clear is that dust particles can carry viruses and bacteria on their backs, as well as a variety of biohazards such as molds and contaminates; and they can be disturbed by very little activity. So be careful before you kick up the stuff.
Some occupations are clearly made much more dangerous because of dust. Coal mining is the classic example; although many machines create machine dust, particularly drills, and dust is always a respiratory problem for firemen and rescue workers. We know that asbestos dust causes cancer, while dust is also a factor in fires and explosions. One can affirmatively state that dust is unhealthy for you to ingest.
One can also definitively say that dust often smells. Old houses smell because the wood and paper are disintegrating into moldy dust. When we turn on the heat in the fall at York Prep, we try to do it on a Friday afternoon because the dust that has collected on the radiators during the summer smells as it is burned off.
I do not know if we come from dust, but the Bible is certainly right that we end as dust. You and I will become the particles in the air that future generations will breathe. Isn’t this fun?
In the meantime, let us revel in our idioms. Dust yourself off, leave your competitors in the dust, and, whatever else, do not bite the dust.
And so ends my minor exploration of this often-overlooked subject, except to say that there is a town in New Mexico called Dusty, and I would not be too proud of the name.
Ronald P. Stewart