[1]Centers for Disease Control anti Prevention;
National Institute for Occupational Safety and Health;
626 Cochrans Mill Rd.;
Pittsburgh;
PA 15236;
USA;
[1]Centers for Disease Control anti Prevention;
National Institute for Occupational Safety and Health;
626 Cochrans Mill Rd.;
Pittsburgh;
PA 15236;
USA;
[1]Centers for Disease Control anti Prevention;
National Institute for Occupational Safety and Health;
626 Cochrans Mill Rd.;
Pittsburgh;
PA 15236;
USA;
[1]Centers for Disease Control anti Prevention;
National Institute for Occupational Safety and Health;
626 Cochrans Mill Rd.;
Pittsburgh;
PA 15236;
USA;
[2]J.H Fletcher & Co.;
Inc.;
402 High St.;
Huntington;
WV 25705;
USA;
Roof bolter; Respirable dust; Canopy air curtain; Coal mining;