Skin sheds dead cells constantly, so a large share of household dust comes from people.

The longer version

Dead cells from the outer layer of skin are constantly being replaced from below. New cells form at the base, then slowly migrate upward, flatten, fill with keratin and eventually die, forming a tough barrier of stacked layers. The outermost flakes are worn away by friction and washed off, carrying with them whatever has settled on the surface.

In an enclosed space with little airflow, those flakes accumulate as part of household dust along with fabric fibres and soil particles. The process is continuous rather than seasonal, though the rate varies across the body and between individuals. Bedding and upholstered furniture collect the most, since people spend long periods in contact with them.

Where this entry sits

These facts look at how the human body works in ordinary moments, from breathing and blinking to balance and sleep. They focus on anatomy, senses, and small reactions that happen constantly without any conscious effort. The full list sits on the Human Body page, where every entry is listed in order.