Why does house dust cause allergies and asthma?
House dust is a mixture of many things that has been shown to include animal dander and hair, fungi or molds, insect proteins (primarily from cockroach), human skin cells, food particles, various fibrous materials of both plant and animal origin and dust mites. In most communities almost all houses contain detectable levels of cat and dog allergens; though the levels are up to 200 times lower in homes without pets than in those with pets. In some individuals even this lower level of allergen is sufficient to cause symptoms. Cats carry large amounts of allergen that is frequently transferred to public places, schools and day care centers on the clothes of their owners. In one study, the amount of cat allergen on a department store display bed reached levels comparable to bedding in homes with cats after 30 days simple from customers (some presumably being cat owners) lying on the bed. Because pet allergens are so easily transferred it is difficult to achieve sufficient reduction in alle
