By Jeffrey the Barak.

As usual, I spent a few minutes today playing with my trusty vacuum cleaner and also a Swiffer duster. And as usual, the vacuum and the duster each had plenty of dust to pick up.

Sometimes I cannot see dust without putting on my eyeglasses, but that’s another problem altogether.

So what is this dust? What was it before it became dust? And how come the room smells so fresh when it has been dusted, but the dust itself seems odorless? Dust raises questions such as these, and cars in the desert raise dust, such as this.

A glance around my home reveals a big clue as to why my dust looks as it does. I may have hardwood floors, but there is a long pile rug in the living room, and that sheds as soon as you look at it. Then there is hair. I shed, and so does my wife. We shed. So much of our dust is from the wool of the rug, which finds its way to the furthest reaches of the other floor of the house, and some of it is our hair.

But not all of it. We are traditionally told that dust mainly comprises of human skin, which we shed constantly as a barely visible fine powder. But I don’t believe it. While I do not dispute the fact that our skin contributes to house dust, more than half of the components of house dust find their way in from outside. Yes outside where every solid object in sight is constantly turning to powder. It may take centuries for some objects to turn to powder, but you can see it happening. Paint does it, brake pads do it, asphalt does it and concrete does it. And the dry soil of the Los Angeles basin does it, a lot. This outside dust is in every breath we take, and it enters the home just as our air does, through the windows, doors, air vents, and even through the solid walls and floors and ceilings.

It joins our skin dust in the bedsheets, on the baseboards and along the edges of the floor. Every day there is a little more to suck up into the vacuum cleaner, or a lot if I am wearing my glasses.

And every three months I open my air filter and there on the media is a  big layer of compressed dust.

It would not be so bad if dust was dead, but it is teaming with life. There are mites in the dust, and the mites defecate. And there are bacteria feeding on the waste from the mites. And bacteria, tiny as they may be, are what produces the smell in a dusty room. So if you can smell it, there are millions of the poo-eating monsters. A room that smells dusty, especially a bedroom, is full of bacteria.

So keep on vacuuming, never choose wall-to-wall carpet if you can have a hard floor, change your bedsheets a lot, and be aware of just what it is you are looking at when you see dust, with or without your glasses on.