[Experimental silicosis. II. Effects of high temperature of fibrogenic effect of quartz and quartz sands used in ceramics].

Fibrogenic effects of siliceous ceramic raw materials (quartz and quartz sand), heated at 1200 degrees C for 72 hours (conditions of ceramic products burning) have been investigated. The evaluation of fibrogenic effects has been based on wet lungs weight and hydroxyproline content in rats' lungs after an intratracheal administration of 50 mg of the test dust, during 3 and 6 months' experiment. The obtained results indicate that high temperature affects the polymorphous transformation of silica. The transformation varies, e.g. crystabillite has been found in quartz, whereas in quartz sands, quartz has been found apart from crystaballite. In the Isere quartz from Nowosolna crystalline silica content has been decreased, as compared to unheated samples. Heating does not reduce fibrogenic effects of some samples e.g. quartz sand from Biała Góra), or the activity may be increased (e.g. quartz sand from Winiary), or is not changed (quartz from Austria). The tendency of changes in biological aggressiveness of siliceous dusts subjected to high temperature cannot be foreseen, as those changes depend on different factos, among others on the content of various impurities.