Respirator usage and effectiveness in bituminous coal mining operations.
D003032:Coal Mining; D004391:Dust / Q000032:analysis; D004781:Environmental Exposure; D005069:Evaluation Studies as Topic; D005374:Filtration; D006801:Humans; D009787:Occupational Medicine; D009790:Occupations; D011482:Protective Devices; D013997:Time Factors; D012122:Ventilators, Mechanical / Q000592:standards
D004391:Dust