Pneumoconiosis: A diffuse parenchymal lung disease caused by inhalation of dust and by tissue reaction to their presence. These inorganic, organic, particulate, or vaporized matters usually are inhaled by workers in their occupational environment, leading to the various forms (ASBESTOSIS; BYSSINOSIS; and others). Similar air pollution can also have deleterious effects on the general population.Coal MiningAnthracosis: A diffuse parenchymal lung disease caused by accumulation of inhaled CARBON or coal dust. The disease can progress from asymptomatic anthracosis to massive lung fibrosis. This lung lesion usually occurs in coal MINERS, but can be seen in urban dwellers and tobacco smokers.Coal: A natural fuel formed by partial decomposition of vegetable matter under certain environmental conditions.MiningSilicosis: A form of pneumoconiosis resulting from inhalation of dust containing crystalline form of SILICON DIOXIDE, usually in the form of quartz. Amorphous silica is relatively nontoxic.Dust: Earth or other matter in fine, dry particles. (Random House Unabridged Dictionary, 2d ed)Dental Technicians: Individuals responsible for fabrication of dental appliances.X-Ray Film: A film base coated with an emulsion designed for use with x-rays.Caplan Syndrome: A condition characterized by the presence of RHEUMATOID ARTHRITIS associated with a specific form of pneumoconiosis, often in coal miners and asbestos workers.Asbestosis: A form of pneumoconiosis caused by inhalation of asbestos fibers which elicit potent inflammatory responses in the parenchyma of the lung. The disease is characterized by interstitial fibrosis of the lung, varying from scattered sites to extensive scarring of the alveolar interstitium.Talc: Finely powdered native hydrous magnesium silicate. It is used as a dusting powder, either alone or with starch or boric acid, for medicinal and toilet preparations. It is also an excipient and filler for pills, tablets, and for dusting tablet molds. (From Merck Index, 11th ed)Occupational Exposure: The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.Quartz: Quartz (SiO2). A glassy or crystalline form of silicon dioxide. Many colored varieties are semiprecious stones. (From Grant & Hackh's Chemical Dictionary, 5th ed)Kaolin: The most common mineral of a group of hydrated aluminum silicates, approximately H2Al2Si2O8-H2O. It is prepared for pharmaceutical and medicinal purposes by levigating with water to remove sand, etc. (From Merck Index, 11th ed) The name is derived from Kao-ling (Chinese: "high ridge"), the original site. (From Grant & Hackh's Chemical Dictionary, 5th ed)Workers' Compensation: Insurance coverage providing compensation and medical benefits to individuals because of work-connected injuries or disease.Silicon Dioxide: Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.Polyvinyl Chloride: A polyvinyl resin used extensively in the manufacture of plastics, including medical devices, tubing, and other packaging. It is also used as a rubber substitute.Radiography, Thoracic: X-ray visualization of the chest and organs of the thoracic cavity. It is not restricted to visualization of the lungs.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Occupational Diseases: Diseases caused by factors involved in one's employment.Maximum Allowable Concentration: The maximum exposure to a biologically active physical or chemical agent that is allowed during an 8-hour period (a workday) in a population of workers, or during a 24-hour period in the general population, which does not appear to cause appreciable harm, whether immediate or delayed for any period, in the target population. (From Lewis Dictionary of Toxicology, 1st ed)Siderosis: A form of pneumoconiosis resulting from inhalation of iron in the mining dust or welding fumes.Mass Chest X-Ray: X-ray screening of large groups of persons for diseases of the lung and heart by means of radiography of the chest.National Institute for Occupational Safety and Health (U.S.): An institute of the CENTERS FOR DISEASE CONTROL AND PREVENTION which is responsible for assuring safe and healthful working conditions and for developing standards of safety and health. Research activities are carried out pertinent to these goals.WeldingPulmonary Fibrosis: A process in which normal lung tissues are progressively replaced by FIBROBLASTS and COLLAGEN causing an irreversible loss of the ability to transfer oxygen into the bloodstream via PULMONARY ALVEOLI. Patients show progressive DYSPNEA finally resulting in death.Vital Capacity: The volume of air that is exhaled by a maximal expiration following a maximal inspiration.Metallurgy: The science, art, or technology dealing with processes involved in the separation of metals from their ores, the technique of making or compounding the alloys, the techniques of working or heat-treating metals, and the mining of metals. It includes industrial metallurgy as well as metallurgical techniques employed in the preparation and working of metals used in dentistry, with special reference to orthodontic and prosthodontic appliances. (From Jablonski, Dictionary of Dentistry, 1992, p494)Asbestos: Asbestos. Fibrous incombustible mineral composed of magnesium and calcium silicates with or without other elements. It is relatively inert chemically and used in thermal insulation and fireproofing. Inhalation of dust causes asbestosis and later lung and gastrointestinal neoplasms.Appalachian Region: A geographical area of the United States with no definite boundaries but comprising northeastern Alabama, northwestern Georgia, northwestern South Carolina, western North Carolina, eastern Kentucky, eastern Tennessee, western Virginia, West Virginia, western Maryland, southwestern Pennsylvania, southern Ohio, and southern New York.Aluminum Silicates: Any of the numerous types of clay which contain varying proportions of Al2O3 and SiO2. They are made synthetically by heating aluminum fluoride at 1000-2000 degrees C with silica and water vapor. (From Hawley's Condensed Chemical Dictionary, 11th ed)Air Pollutants, Occupational: Air pollutants found in the work area. They are usually produced by the specific nature of the occupation.Respiration Disorders: Diseases of the respiratory system in general or unspecified or for a specific respiratory disease not available.Bronchitis: Inflammation of the large airways in the lung including any part of the BRONCHI, from the PRIMARY BRONCHI to the TERTIARY BRONCHI.Rheumatoid Nodule: Subcutaneous nodules seen in 20-30% of rheumatoid arthritis patients. They may arise anywhere on the body, but are most frequently found over the bony prominences. The nodules are characterized histologically by dense areas of fibrinoid necrosis with basophilic streaks and granules, surrounded by a palisade of cells, mainly fibroblasts and histiocytes.Laboratories, Dental: Facilities for the performance of services related to dental treatment but not done directly in the patient's mouth.PolyvinylsForced Expiratory Volume: Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.