007980000a22001930004500003000900000005001700009110013700026245018100163020001800344264004900362490004000411300000900451041000800460650002700468650005000495650002000545650000900565700003000574PH-MaWHO20241108112343.0 aWHO Study Group on Recommended Health-Based Limits in Occupational Exposure to Selected Mineral Dusts (Silica Coal) (1984 : Geneva). aRecommended health-based limits in occupational exposure to selected mineral dusts (silica, coal : report of a WHO study group [meeting held in Geneva from 6 to 12 March 1984]. a92-4-120734-5 aGeneva : bWorld Health Organization,c1986. a(WHO technical report series ; 734) a82p. aeng aEnvironmental exposure aOccupational diseasesxPrevention and control aSilicon dioxide aCoal aWorld Health Organization