Photo: Chapendra (flickr)
Do you ever find little fluffs of lint trapped in your bellybutton? What is that stuff, and where does it come from?
Inside The Investigation
Dr. Karl Kruszelnicki, a physicist from the University of Sydney was on an Australian public radio show when a listener called in to ask these same questions. “Dr. Karl” realized that no one actually knew the answers, and set out to investigate this fuzzy phenomenon.
His team surveyed nearly 5,000 men and women from all over the world about their bellybutton lint, and their age, sex, body hair, body shape, clothing type, and several other factors that could influence lint formation.
An additional 200 participants also agreed to shave their belly hair and compare bellybutton lint before and after shaving, to test the hypothesis that body hair affects bellybutton lint accumulation.
Finally, the researchers examined samples of bellybutton lint from many people to identify what the belly fuzz was made of.
So, What Is Bellybutton Lint?
Using electron microscopy, the team found that bellybutton lint is primarily composed of cloth fibers and dead skin cells.
In general, most bellybutton lint generators are middle aged, hairy, slightly overweight males. People with very little or a great deal of belly hair were least likely to have belly button lint, and shaving the hair around the navel prevented fluff accumulation.
How Does It Work?
It seems to work like this: small fibers shed from your clothes get trapped in your body hair.
The hair on your abdomen typically curves towards your navel. As your body moves, the friction between your body hair and clothing ratchets the lint along a “hair highway” that leads straight to your bellybutton.
If you do find fluffs of lint in your bellybutton, don’t worry–the study also concluded that navel fuzz is completely harmless and requires no corrective action.
- The Great Bellybutton Lint Survey (ABC)