Particulate matter is the general term for all solid particles and liquid droplets floating in the air, including airborne dirt, dust, smoke, and pollen.  Particulate matter irritates the respiratory system, and the smaller, fine particles travel deeper into the lungs and have been linked to premature deaths, chronic bronchitis and aggravated asthma.  Particulate matter also reduces visibility in all areas, including our national parks and wilderness area. 

View photos from the National Campaign Against Dirty Power

   Smoky Mountains on a clear day.          Smoky Mountains on a hazy/smoggy day.