Respirable Dust and Quartz Exposure from Three South African Farms with Sandy, Sandy Loam, and Clay Soils

Andrew J. Swanepoel, Hans Kromhout, Zubair A. Jinnah, Lutzen Portengen, Kevin Renton, Kerry Gardiner and David Rees

The Annals of Occupational Hygiene 55 ( 6 ): 634 - 643 , 2011