What color is your belly button lint?

March 2, 2009 9:18 AM

LintFilter: Why is my belly button lint always blue or blue-gray?

I've noticed, over the years, that the lint that accumulates in my umbilicus (belly button) is always blue or blue-gray. This wouldn't seem odd to me if I wore only blue or gray shirts. But I always wear white t-shirts under my button-down shirts. So my question is, why is the lintball that accumulates not white? When I run a load of white T-shirts in the dryer, the lint in the lint-screen is white.

Has anyone else noticed this (for themselves)?

Bonus question: I have a fairly hairy torso -- not Robin Williams hairy, but close. I suspect that this contributes to the amount of lint that I accumulate, but am unwilling to do the experiment needed to prove this as it would involve body-waxing. Do men without substantial body/abdominal hair or women (presumably without substantial body/abdominal hair) collect a lot of belly button lint?

I know that this question borders on absurd/gross, but I'm snowed in with my 2 year old daughter, and so am not thinking about the more profound questions of life today.

posted by scblackman to health & fitness (19 comments total)

I'm a woman and have never had lint in my belly button. Alas.
posted by iconomy at 9:21 AM on March 2 [1 favorite]

Do you tend to wear denim jeans? That was what first came to my mind.

As for myself, a woman with not a lot of abdominal hair, I don't collect a lot of belly button lint.
posted by harrumph at 9:22 AM on March 2

This was tested on the pseudo-scientific Brainiac show, and the upshot was that belly button lint is a mix of shirt and underwear lint. They tested it by having a guy wear a white shirt and red shorts and go for a run, and his belly button lint ended up a mix of those two colors. If you usually wear dark pants or underwear, that's probably causing the color.

I consistently get belly button lint myself; my smooth-bellied fiancee never gets it. I'm pretty sure it's down to abdominal hair, as you suspect.
posted by pocams at 9:23 AM on March 2 [1 favorite]

Basically blue-grey is a combination of what fibers look like at a microscopic level. Take a look at your dryer lint. Even if you only wash white clothes it will look blue grey.

Hair acts like a convener belt to the belly button. Less hairy people commonly have none or next to no belly button lint on average.

http://en.wikipedia.org/wiki/Navel_lint#cite_note-1
posted by zephyr_words at 9:25 AM on March 2

I recall a guy that was on Letterman years ago, who had collected his belly button lint in jars for a long time. His lint changed colors when he replaced his towels with a different color. Do you have blue towels?
posted by Mark Doner at 9:26 AM on March 2

Recent study would seem to confirm your Bonus Question:

"The hair's scales act like a kind of barbed hooks..."
posted by Dali Atomicus at 9:27 AM on March 2

Dr. Karl's Navel lint survey.
The take-home answer on lint...
You're more likely to have Belly button Lint (BBL) if you're male, older, hairy, and have an innie.

More specifically...

+ You get more BBL as you get older
+ More men have BBL than women
+ Lint colour reflects your skin tone - lint is lighter for light skinned people.
+ Skin type does not affect BBL.
+ BBL appears to be related to hairiness.
+ Too much belly hair, or too little belly hair somehow inhibits the movement of BBL into the belly button.
+ There is no relationship between BBL and a person's overall build.
+ Anecdotal evidence suggests that navel rings dramatically reduce BBL or even remove it altogether.
+ It seems as though the Snail Trail has something to do with BBL levels.


More recent research:

Chemical analysis revealed the pieces of fluff were not made up of only cotton from clothing. Wrapped up in the lint were also flecks of dead skin, fat, sweat and dust.

Dr Steinhauser's observations showed that 'small pieces of fluff first form in the hair and then end up in the navel at the end of the day'.

Writing in the journal Medical Hypotheses, he said the scaly structure of the hair enhances the 'abrasion of minuscule fibres from the shirt' and directs the lint towards the belly button.

The great minds of science also ponder these things. The summary: dead skin cells contribute a lot to navel lint. They may be generating some of the blueness, kinda like how skin dust is a sort of blue-grey. The Kruszelnicki study suggests some sort of bacteria at work too -there are some choice shots in there with jars of lint changing colour.

For the record, I am a 27 year old smooth bellied woman and I do not get navel lint at all.
posted by Jilder at 9:30 AM on March 2 [2 favorites]

I have noticed this myself, and I thank you for asking this question. It's always a medium blue-gray, regardless of what I wear.
posted by DarkForest at 9:32 AM on March 2

Interesting - I'm a decently fuzzy-tummied male, and mine changes with my shirts (and possibly my underwear - most of my undies are in the white/blue range, with some tans). Also, my dress shirts tend to produce less than my t-shirts, possibly because of the smoothness of the fabric weave of dress shirts.
posted by filthy light thief at 9:39 AM on March 2

Oh scblackman, thanks for asking this question (though I do hope you go out and play a bit in the snow with your 2 year old), and Jilder and everyone, thanks for all the info., including Dr. Karl's navel lint survey (who knew?). As someone without a belly button (eliminated via surgery at a young age), I can only vicariously enjoy this stuff, but this is classic internet fun!
posted by gudrun at 9:45 AM on March 2

Another fuzzybelliedmale here. And mine generally changes with the color of my shirt. I typically wear white undershirts, and when I do the bbl is usually gray/blue. In the summer my uniform typically involves brightly colored polo shirts - which means I have technicolor bbl for those summer months.
posted by greekphilosophy at 10:47 AM on March 2

Thanks, all, for the rapid and comprehensive replies and links. This is why I love MetaFilter.
posted by scblackman at 10:51 AM on March 2

Jilder's response on the content of belly button lint just made "I recall a guy that was on Letterman years ago, who had collected his belly button lint in jars for a long time" so much less attractive.
posted by nzydarkxj at 11:10 AM on March 2

27 y.o. male, medium amount of body hair, what I would guess is a slightly above-average of belly button lint. And yes, always somewhere in the grey-blue-black spectrum.
posted by penduluum at 12:48 PM on March 2

Add me to your sample. Also always in the grey-blue-black spectrum. For full disclosure, I tend to wear a lot of white t-shirts but blue jeans and dark undies. Based on that, perhaps the secrets of general relativity can be found in the careful gazing of our navels and that which they may contain.
posted by drpynchon at 2:35 PM on March 2

Good Grief!
Dr Georg Steinhauser of the Vienna University of Technology was interviewed this morning about his study on belly-button lint on the Radio NZ National programme.
OGG
MP3
What kind of bizarre zeitgeist effect is going on here?
posted by Catch at 2:37 PM on March 2

Fascinating. I was listening to NPR this morning in the shower, but there was no mention of the story. I was simply contemplating the the previous day's belly button capture and wondering what it was blue (when I wire a white oxford with white t-shirt).

Perhaps it was the combination of the water and the fillings and the lack of a tinfoil hat that gave me such good reception for Radio NZ.
posted by scblackman at 4:04 PM on March 2

Belly hair definitely affects amount of BBL. I waxed mine recently at my girlfriend's request and my BBL disappeared until the hair grew back.
posted by thekiltedwonder at 5:55 PM on March 2

I've been beaten to the story, but here is a link to the Great Belly Button Lint Survey.

Dr Karl earned an igNobel Prize for it!
posted by Flashduck at 10:49 PM on March 3