Does dust consist primarily of human skin?

It's a widely repeated factoid that dust consists primarily of human skin. For instance, one can find this piece of information in the first paragraph on the wikipedia page about dust. But Paloma Beamer, a dust expert at the University of Arizona, disputes this claim. From

Beamer says there are really only two places dust can come from: outdoors and indoors. We are an important part of the process of getting the outdoor stuff indoors. We bring it with us when we enter a house — through "soil particles that come in on your shoes," says Beamer, or tiny particles suspended in the air when we open the door and walk in.
Then there's the indoor component of dust. "Like pieces of your carpet fiber or your furniture, your bedding, or anything like that that starts decaying," she says. Then there are organic contributors. "Skin flakes and the dander off your pets, and other insects or bugs that might be in the home."
Now, as anyone who's looked under a sofa knows, there's dense dust and there's fluffy dust.
"A lot of the fluffy things, I think, tend to do more when you get a lot of fibers. In my house, it comes from cat hair," Beamer says.
Beamer's interest in dust stems comes from her effort to measure people's exposure to toxic substances. In a recent paper in the journal Environmental Science and Technology, she calculates the proportion of dust that's from indoor sources, compared with the amount from outdoor sources. She figures that one-third comes from indoor inorganic sources like carpet fibers. "Two-thirds comes from both soil tracked in, and the outdoor air particles," Beamer says.

I'm inclined to think Beamer is right. I find it hard to imagine that the volume of dust in my house comes primarily from the dead skin cells of my wife and I.

Urban Legends

Posted on Wed Nov 11, 2009


Wasn't there some kid who won a science prize for "proving" that dead dust mites make up 1/3 of the volume (or weight?) of a one-year old pillow?
Posted by Joel B1  in  Hobart, Tasmania  on  Wed Nov 11, 2009  at  09:35 PM
How does one get to be a "dust expert"? Surely it's not a full time job, is it?
Posted by Captain Al  in  Vancouver Island, Canada  on  Wed Nov 11, 2009  at  10:17 PM
If dust was made up primarily of human skin, or things we track in, or furniture decaying, how do empty houses get so dusty? That ones always puzzled me.
Posted by Nona  on  Thu Nov 12, 2009  at  06:01 AM
I never believed the "mostly human skin" thing anyway. I live in Florida...we have enough sand around here to easily see what is really making up most of our dust. I did always wonder why the dust in my office building was BLUE and not the standard grey.
Posted by Maegan  in  Tampa, FL - USA  on  Thu Nov 12, 2009  at  07:50 AM
I think the popular claim is that skin flakes make up most of (indoor) house dust, not all the dust in the world.

Even that seems highly suspect, though. Numerous as people are, they make up a rather small percentage of the total amount of material on the earth's surface, so it would be rather amazing if they could produce more dust than everything else.

Based on what I get when I sweep, I'd say most of the dust in my house is made of cat fur and bits of cat litter.
Posted by Big Gary  on  Thu Nov 12, 2009  at  07:51 AM
Our skin color is just a pigment, it does not make our dust any different from anyone else's. What kind of question is this?

And we use Afrosheen so we don't have to smell like nada.
Posted by search engine marketing tips  on  Thu Nov 12, 2009  at  09:23 AM (QI is a highly popular British tv-show)
Posted by Jerry S  on  Thu Nov 12, 2009  at  12:32 PM
there would have to be alot of dead people floating around in space with all the dust thats out there...
Posted by mysticx0  on  Thu Nov 12, 2009  at  12:43 PM
Yeah, I'd think that the percentage of various substances in the composition of dust would depend on where and when that dust is accumulating. In a crematorium, it could very well be largely composed of human skin (and muscle and bone and whatever else). In a large house in the middle of a desert inhabited by one person, shed skin flakes would be greatly outnumbered by fine sand. You can't just say, "dust is mainly composed of such-and-such" unless you have taken a sample from everywhere on the planet, analysed it, and then averaged the results.
Posted by Accipiter  on  Thu Nov 12, 2009  at  05:26 PM
Interesting topic. What about pets? Do they leave skin particles?

Do skin particles contain DNA? if so, in theory, i'd visit another person's house and then THEIR skin would get on me and thus their DNA would be on me...

Posted by Dan  on  Tue Nov 17, 2009  at  02:23 PM
Early fantasy writer Jack Vance (him of "Cugel" fame) postulated a religion set in the dying days of Earth whose devotees wouldn't walk on land except on elaborate wooden shoes due to the supposed "thickness" of deceased human bits after several millennium.

I think he might have been onto something there.
Posted by Joel B1  in  Hobart, Tasmania  on  Fri Nov 20, 2009  at  02:45 AM
Sand is very dense, dry skin flakes light. We compare rocks with pop-corn. Even 10% of skin may probably bring 50-70% of volume.
Posted by xop  on  Wed Nov 25, 2009  at  12:48 PM
The Jack Vance story is 'The Eyes of the Overworld' and the people who won't walk on the ground are Funambulists - they travel around town on tightropes, and wear the special shoes when they have to leave town. (A Funambulist is a tightrope walker.) A sceptic counters that if there was really a deep layer of human remains all over the planet, there would be cliffs everywhere the land meets the sea.

(Quoting from memory here....) '"By no means," replied the Funambulist, with the zeal that characterises his kind. "We assert that the exhaled moisture in human breath has raised the sea by a precisely equal amount."

It's a great book. That last bit reminds me that I've also heard it stated as fact that the water we city-dwellers drink has all passed through the human body several times.
Posted by Mr Henderson  on  Wed Dec 02, 2009  at  12:23 PM
Funny, over 30 years on the planet and I'd never heard the 'dust is mainly human skin' trope. (Still: it's bollocks on the face of it.)
Posted by outeast  on  Tue Dec 08, 2009  at  06:45 AM
I do not believe that dust is made of human skin. That we shed our skin and renew our skin daily but that drops to the floor and maybe a little when there is wind. But when it rain it is taking away with the water.
Posted by sam  on  Fri Jun 11, 2010  at  06:10 PM
A sceptic counters that if there was really a deep layer of human remains all over the planet, there would be cliffs everywhere the land meets the sea.
Posted by bar crawl  on  Thu Aug 05, 2010  at  10:16 PM
nice and really a good post
Posted by limsat ultra  on  Sat Aug 21, 2010  at  10:01 AM
It is not possible to have too much dust a clean surface
Posted by Ozlem Uguz  on  Sat Oct 30, 2010  at  08:10 PM
I was always suspicious of the idea that dust was made up of skin. It was the wrong color -- the color of my towels or my carpet. And I took dust samples to school and looked at them under a microscope and they were fibers. Skin is not fibers. So that settled that.
Posted by scuzzy  on  Sat Jan 12, 2013  at  12:57 PM
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