What we call dust is a complex mixture of pet dander, fungal spores, tiny particles, soil tracked in on your feet, carpet fibers, human hair and skin. Dust itself is an allergen and it can contain harmful chemicals.
Harmful chemicals in dust come from both inside and outside your house. Indoor items like furniture, electronics, shoes, plastics and fabrics can shed chemicals, while outdoor pollutants can enter on your shoes, and through windows and doors.
As highly flammable synthetic materials have replaced less-combustible natural materials, harmful chemical flame retardants have been added to thousands of everyday products, including furniture, computers and TVs. These chemicals escape from consumer products and settle in household dust. Older homes built before 1978 may also contain lead paint, which could be a source of lead in dust.
Young children are especially at risk from dust, because their developing bodies are more vulnerable to toxic chemicals, and they ingest or inhale more dust than adults as they spend more time on the floor. They also often put their hands and toys in their mouths.