[Fibrogenicity of dust emitted by highly aluminiferous refractories]

The authors proved variable clinical and pathogenetic features of disease in workers under long occupational exposure to dust of kaolin and its baking products. Therefore, special experimental studies should cover kaolin and mullite as primary and final product in entire technologic sequence of high-alumina refractories production. Natural refractory clay and mullite dust were administered to rats intratracheally during chronic experiments. Lungs of the rats exposed to mullite dust demonstrated reliable changes of lipid content in 1 month and those of hydroxyproline content--in 3 months. When exposed to intratracheal administration of kaolin and mullite dust, respiratory system develops typical changes--slow development of benign diffuse and sclerotic form of pneumoconiosis that is associated or, more frequently, preceded by chronic dust bronchitis.