By Jim Oltersdorf on Friday, April 16, 2004 - 04:47 pm:
Is it possible to determine and detect molecular residual matter left by a human that was once in a room?
Thanks!
Jim/Alaska
By Anonymous on Friday, April 16, 2004 - 06:26 pm:
Depends on what he left...
By Anonymous on Monday, May 3, 2004 - 09:52 pm:
Yes ... I think so ....... : )
By Anonymous on Tuesday, May 4, 2004 - 11:22 am:
We humans are constantly leaving a lot of traces of ourselves behind. A large proportion of the dust in our houses consists of hair and sloughed-off skin cells (dust mite fodder) -- various web sources indicate that we lose 30,000 - 40,000 skin cells per MINUTE. That's why clean rooms and bunny suits are needed to prevent contamination in semiconductor manufacture. (A talk I recently attended expressed concerns about how challenging it will become to look for evidence of life on Mars if the red planet gets inadvertently contaminated with lots of human DNA.) Hairs are shed at a lower rate -- 75-150/day from the scalp.
Bottom line: your visitor may have left a few hairs, and certainly would have left some skin flakes, but unless the room was very clean before the visit, and unless that visit was relatively recent, you'd likely have trouble isolating that person's genetic material, amid all the debris left by other people. Good luck.