What are the main components and causes of household dust?

Dust is mainly human skin cells. The average person loses between 50-100 thousand skin cells every minute. Those flakes of skin accumulate in carpets and furnishings, dry out and then are lifted into the air by drafts or air currents.Because dust mainly consists of skin cells, it's nutritious and there are some things that will eat it. House dust mites are a microscopic organism which eat these skin cells -asthma sufferers are often allergic to their poo, which is carried into the air, and can irritate the lungs.