When your air ducts are not properly maintained, they can fill with dust, dirt, and debris, such as pet hair, pollen, and even outdoor pollutants. All this is recirculated and blown throughout your home. DID YOU KNOW? The EPA has identified indoor air pollution as one of the top five environmental risks to public health? Not only does this spread unwanted dust and debris throughout your home, it can also adversely affect allergies and other health conditions.