Carpets collect dust tracked in on shoes or on the feet of pets.
They can also absorb airborne chemicals from tobacco smoke, pollution or aerosols produced during cooking. Harmful substances that collect there include lead, cadmium, mercury, pesticides and carcinogenic compounds. The Guardian explains that young children may be most at risk from exposure to toxins that collect in carpeting because they spend a great deal of time playing on the floor. Children are also known to be more sensitive to certain toxins like lead and mercury because their bodies are still developing. HealthScout recently described how some health experts suspect that carpeting in schools contributes to childhood allergies.