Respiratory Diseases affect the organs that are involved in breathing. These include the nose, throat, larynx, trachea, bronchi, and lungs. A respiratory disease of particular concern to miners is pneumoconiosis, which is a general term for diseases of the lungs caused by the inhalation of respirable-sized dusts. Respirable dust is defined as being less than 10 microns in diameter, and is invisible. Airborne respirable dust that is inhaled by miners can be deposited in the lungs and cause damage to the lung tissue. In mining, the cutting, breaking, crushing, drilling, or grinding of coal, ore and surrounding rock produces airborne respirable dust. If sufficient dust deposition and lung damage occurs, a miner can develop pneumoconiosis. Although mild cases of pneumoconiosis may not produce any symptoms, there is a danger that the disease could progress to become disabling or fatal.

Coal Workers´ Pneumoconiosis (CWP), commonly called Black Lung, is a lung disease caused by inhaling excessive amounts of coal mine dust. The likelihood of developing CWP increases with exposure to higher levels of respirable dust in the mine air and more time spent working in coal mining. Since 1970, NIOSH has offered periodic lung examinations to miners through the Coal Workers' X-Ray Surveillance Program. Among miners examined in the X-Ray Surveillance Program between 2000 and 2006 who had 25 or more years of experience, one out of every 13 was diagnosed with pneumoconiosis.

Another form of pneumoconiosis that is of great concern to miners is silicosis, a disabling and often fatal lung disease caused by breathing respirable-sized dust that contains elevated levels of crystalline silica. In mining, crystalline silica can often be found in rock strata associated with or surrounding the material being mined. Silica dust is more toxic than coal dust. Of people who died of silicosis during the 1990s, mining machine operator was the occupation most frequently listed on the death certificate.

Once contracted, CWP and silicosis cannot be cured, so it is critical to reduce the respirable dust exposure of miners to prevent the development of these diseases.

The work in this topic area is supported by the NIOSH Mining Dust Monitoring and Control and Diesel Monitoring and Control programs. See the NIOSH Mining Products page for software, guides, training materials or other items related to this topic.