What is dust made of?

Dust particles can consist of a variety of substances that includes outdoor pollens, mold spores, dirt and sand. Human skin, animal skin, hair and carpet fiber particles are common substances found in indoor dust. Dust can also travel into the earth's atmosphere from space.

Additional substances that can create dust include cigarette smoke, food particles, lead, insect particles and arsenic. The specific particles found in dust can vary depending on external factors, such as climate, and internal factors, such as cleaning and cooking habits. Dust that contains outdoor pollens can cause allergy symptoms in certain individuals. Dust containing arsenic or lead can pose health risks to adults and children.