Posts Tagged ‘Odor’

Humans stink more than other animals

February 27, 2011
A female mosquito of the Culicidae family (Cul...

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A new paper in Trends in Parasitology, 20 January 2011, 10.1016/j.pt.2010.12.009

Sweaty skin: an invitation to bite? by Renate C. Smallegange, Niels O. Verhulst, Willem Takkenby

Out pet cats and dogs with their enhanced sense of smell probably have to put up with much greater olefactory trauma due to smelly humans than their owners ever have to due to smelly pets.

Discovery News writes:

Pungent body odor from sweaty adult human skin is unique in the animal kingdom. Humans turn out to be particularly smelly because odors are released from nearly every part of the body while other species living on us are simultaneously emitting odors too.

Lead author Renate Smallegange explained to Discovery News that “the microorganisms on our skin use the materials present on our skin and in our sweat for their own metabolism. The microorganisms convert non-volatile compounds into volatile compounds.”

Smallegange, a Wageningen University entomologist, and colleagues Niels Verhulst and Willem Takken, analyzed data on the chemical structure of human sweat. They conclude that “sweat-associated human volatiles are probably the primary determinant factor in the host preference of anthropophilic mosquitoes.” These insects can carry life-threatening diseases, such as dengue, yellow fever and malaria.

So far, the “recipe” for synthetic human sweat appears to contain a complex blend of carbon dioxide, ammonia, lactic acid, and seven other carboxylic acids. The latter “have a sweaty smell,” Smallegange said. Mosquitoes are very attracted to this odorous concoction when scientists whip it up in the lab. ……

Adult humans instead frequently emit water, proteins, amino acids, urea, ammonia, lactic acids and certain salts — much of which can stink. During puberty, the glands that release these components mature and are colonized by bacteria.

“So even though parents can recognize their preadolescent children by olfaction, children have a less ‘pungent’ body odor compared with adults,” the researchers explained, adding that children also produce sweat at a lower rate than adults do.

The mosquitoes studied by the scientists bite sweeter smelling infants and children less frequently. Having a strong body odor can be useful at times, however. Smallegange mentioned that the odors that emerge during and after puberty are likely tied to “sexual maturity and mate choice.” Prior research determined that we can even distinguish ourselves based on hand smell alone.

The scientists further report that men sweat more than women do during exercise. Nevertheless, the concentrations of smelly, volatile carboxylic acids are basically the same for men and women.


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