Smells serve as a primal alarm system alerting humans to dangers in our environment, like fires or gas leaks. A diminished sense of smell in old age is one reason older individuals are more prone to accidents, like fires caused by leaving burning food on the stove.
Michele Miller of Bayside, New York, was infected with the coronavirus last March, and hasn’t smelled anything since then. Recently, her husband and daughter rushed her out of their house, saying the kitchen was filling with gas.
She had no idea. “It’s one thing not to smell and taste, but this is survival,” Miller said.
Humans constantly scan their environments for smells that signal changes and potential harms, though the process is not always conscious, said Dr. Dalton, of the Monell Chemical Senses Center.
Smell alerts the brain to the mundane, like dirty clothes, and the risky, like spoiled food. Without this form of detection, “people get anxious about things,” Dr. Dalton said.