Experimental pneumoconiosis due to dusts of ore mines, I.

Male CFY rats were injected into their trachea with a suspension of dust of ore mine dead rock of high quartz content and mixed composition (particle size: 0-60 micrometers). Three and six months after treatment, foreign body granulation and after twelve months a non-fibrotic diffuse lung disease was seen in the animals. After twelve months of exposure, non-specific, mature sinus histiocytosis and small focal epitheloid cell reaction were found to develop in the cervical, lung-hilar and retroperitoneal lymph nodes. The histopathological changes were compared with those seen in experimental silicosis induced by DQ12 quartz. It is concluded that the hazardous effect of industrial dusts is not identical with their fibrogenic effect.