Dust allergies are extremely common these days but you can't have an (IgE mediated) allergy to asbestos or smog. Generally the immune system reacts to biologi

Dust allergies are extremely common these days but you can't have an (IgE mediated) allergy to asbestos or smog. Generally the immune system reacts to biological substances. We're vastly more sterile from a germ perspective. The term "hygiene hypothesis" is apt.