I've heard several times that 90% of dust is flaked off human skin. But, this doesn't make sense to me. If it were true, wouldn't we be more likely to encounter dust storms in a large city with many inhabitants instead of in or near deserts? Do they mean inside buildings like homes? But even there, I've noticed that the amount of dust seems to vary based on other things than the number of inhabitants. (For instance, an apartment with cheap carpets has much more stuff in the air than a home with hardwood or linoleum floors?)
Does any one know where this 90% skin idea originated? Is there any data to back it up? Or is it just one of the urban legends or myths that someone made up and everyone repeats?
- There's a difference between atmospheric dust and house dust. See the Wikipedia article on dust which says:
- dust occurs in the atmosphere from various sources: soil dust lifted up by wind, volcanic eruptions, and pollution
- The dust which collects in houses is composed of atmospheric dust combined with dust generated by the inhabitants, mostly from sloughed skin cells and fibers from clothing and coverings.
Since fibrous dust is larger and lighter than mineral dust one might assume that this is the dust in question. Besides tiny lint fibers that are sloughed off from man-made textiles I would say that most house dust is created from paper products such as tissues and toilet paper. Rip off some toilet paper and wipe it on your butt in a good lighting situation (i.e. beam of light with a dark background) and you will be amazed at how much dust is created from that one act.