1994i-842 adverseeffects asbestos asbestosis asphyxiatingandpoisonousgases carcinogens chemicallyinduced coalminers coalmining congresses cytopathology diseases diseasesandhygiene dust employers'liability environmentalcarcinogens environmentalexposure governmentpolicy history industrialhygiene inhalationexposure inhalationtherapy laborunions lungneoplasms lungs minerals miners molecularaspects occupationaldiseases pneumoconiosis qv610c3931994 respiratoryorgans silicosis socialaspects soot talc titanium toxicity toxicology tumors unitedstates workers'compensation