National Institute for Occupational Safety and Health (U.S.)PneumoconiosisCoal MiningCoalAnthracosisMiningDustSilicosisCoal TarOccupational ExposureOccupational DiseasesAppalachian RegionMaximum Allowable ConcentrationSilicon DioxideRadiography, ThoracicDental TechniciansX-Ray FilmCaplan SyndromeLuffaAsbestosisLungQuartzVital CapacityPulmonary FibrosisOccupational HealthTalcWorkers' CompensationForced Expiratory VolumeRadonCoal AshKaolinUranium