The nose knows: Scientists reveal humans can smell a trillion odours

Scientists studying the breadth of people’s sense of smell say the human nose can discern far more than the 10,000 different odours long cited as the outer limit of our olfactory abilities.

They concluded that the human nose can differentiate an almost infinite number of smells – more than a trillion – based on their extrapolation of findings in laboratory experiments in which volunteers sniffed a large collection of odour mixtures.