Muladhara chakra, located at the base of the spine, is associated with the sense of smell. Recall Hannibal Lecter's use of his sense of smell, upon first encountering Starling in The Silence of the Lambs: Lecter says to her, "You use Evyan skin cream, and sometimes you wear L'Air du Temps, but not today."
Above left and right: Lecter can detect Clarice's scent through the ventilation holes at the top of his cell front plexiglass barrier.