Epidemiologic and in vivo studies suggest that crystalline silica,transition metals and carbonaceous compounds may be responsible for a number of adverse health effects, including cancer(e.g., Dutta and Moudgil1 and Valavanidis et al.2). This fact posesserious questions concerning health risks in iron foundrieswhere numerous sources of inhalable quartz, metal and carbonparticles are present (e.g., National Occupational Health andSafety Commission3).