Is dust really people?

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0:00(finger squeaking)

0:01- Is dust just people?

0:04You may have heard, like me, that the dust

0:06that collects around your house

0:07is mostly made of dead human skin cells.

0:11Is that really true?

0:12Well, as usual, the answer's more complicated

0:14and more interesting, but that's also not totally wrong.

0:18Humans shed about a gram of skin every day.

0:20We actually replace our entire outer epidermal layer

0:23every two to four weeks.

0:24That means that your dead body does make up

0:26a significant portion of the dust on your windowsill,

0:29but dust is also much more than that.

0:31Under a microscope,

0:32dust contains a whole world of shapes and colors.

0:34It's almost beautiful in a really gross way.

0:37Now, one famous study of households in the Midwest

0:40found that a third of dust comes from stuff inside the home.

0:43In addition to skin cells from you and your pets,

0:46that includes food debris and fibers from clothing

0:48and furniture, plus microscopic dust mites

0:50just feeding on all that debris

0:52from you and your belongings.

0:53But the other two thirds of household dust

0:55actually comes from outside the house,

0:57including dirt, pollen, feces, eh,

1:00environmental pollutants.

1:01There's even trace amounts of space minerals from meteorites

1:04and distant exploding stars that just shower down to Earth.

1:07Dust is basically just a microcosm

1:09of your local environment.

1:10In fact, it's even used by forensic scientists

1:13to help solve crimes.

1:14The DNA entombed in dust from a person of interest

1:17can help provide valuable information

1:19about where they may have traveled.

1:21So dust is people. It's just more than that, too.

1:24Guess that puts a whole new meaning

1:25on cleaning up after yourself.

1:27Follow me for more cool science videos.

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