We thought the human nose could detect 10,000 odors. Turns out, the real number is a TRILLION

Smelling tree
CC BY-SA 2.0 Flickr

Maybe smell pollution will be taken more seriously someday

These days, noise and light pollution are being taken more seriously than they used to be. Maybe someday smell pollution will also get more attention. The latest science on the human nose certainly supports the view that our noses are a lot more sensitive and sophisticated than we thought. Since about 1927, we've believed that the 400 olfactory receptors in our noses could detect about 10,000 different odors. That might sound like a lot, but we know that the human eye can detect about 10 million different colors.

But there was a little hiccup: That assertion about 10,000 odors was taken mostly on faith, as it didn't rest on solid scientific evidence.

That has now changed thanks to researchers at Rockefeller University in New York City. By mixing together 128 different-smelling molecules, they tested various smells on volunteers to determine how many different smells they could perceive. Based on these results, the scientists extrapolated that the human nose could discriminate between at least one trillion different smells, and even that might be underestimating it.

Most of what we thought we knew about our sense of smell was more or less "urban legends", according to one of the authors of the study. "It's the first real test of how good humans are," she told the BBC. "People assume animals are much better smellers than us. Humans are remarkably good at smelling things."

This doesn't mean that we're going to out-smell Fido any time soon. Animals are still 2-3x better than us in that regard, and they dedicate a bigger part of their brains to the sensory input from their noses. But the power of the human sense of smell should not be underestimated, and should definitely be used more by those of us who don't even attempt to train their noses, or take the time to literally stop and smell the roses.

Via Science, BBC

See also: Paralyzed dogs made to walk again after nose cell transplant (Yes, from their noses)

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