Posted by: Prospector PJ18 MAR 2014
Ear wax, or cerumen, could reveal a great deal of information about an individual, such as health status, personal identity, gender and sexual orientation, researchers have suggested.
This type of information can also be elucidated from underarm odours, and researchers suggested a link after discovering that a small change to gene ABCC11 is related to underarm odour production and to a person’s type of cerumen.
Individuals of East Asian and Native American descent have a form of ABCC11 that codes for both dry-type cerumen and reduced underarm odour relative to individuals of other ethnicities, who typically produce a wet-type ear wax and greater body odour.
The researchers, from the Monell Chemical Senses Centre in Philadelphia, have suggested that the fatty nature of cerumen makes it a likely repository for lipid-soluble odorants produced by certain diseases and the environment. At least two odour-producing metabolic diseases (maple syrup urine disease and alkaptonuria) can be identified in cerumen before they can be diagnosed using blood or urine analysis.
If a 10in-long earwax plug pulled from a blue whale is anything to go by, this bodily secretion in humans could contain all sorts of information. Because the wax is laid down in light and dark bands, analysis revealed the timing of certain events in the whale’s life.
During its 12-year life, the whale had come into contact with 16 persistent organic pollutants, including pesticides and flame retardants. Exposure was greatest during its first year, suggesting a transfer of contaminants from the mother in the womb and during nursing. Concentrations of cortisol, the stress hormone, doubled over the whale’s life and peaked directly after the whale reached sexual maturity, suggesting stress from sexual competition.