[Polish asbestos and its fibrogenic effect. II. Identification and fibrogenic effect of fibrous minerals occurring in road stone deposits].

Fibrogenic properties of a fibrous mineral occurring in road stone deposits mined at Nasławice at the Lower Silesia have been tested. Diffractometric and infrared absorption spectra tests identified this mineral as antigorite. The content of free crystalline silica was 1.3%. The dust (50 mg) obtained from the test mineral when intratracheally administered to experimental animals as a suspension in physiological NaC1 solution yielded statistically significant increases of the lung weight and hydroxyproline content, as compared to controls. The mean weight of experimental animals' lungs after 3 months was 1898.4 mg, after 6 months--2116.8 mg, after 9 months--2878.4 mg. The control animals' lung weight was 1409.6 mg after 3 months, 1634.4 mg after 6 months and 1939.9 mg after 9 months. Hydroxyproline content in experimental animals' lungs was 5.1 after 3 months, 5.8 mg after 6 months and 8.6 mg after 9 months. In controls, hydroxyproline content in lungs was, respectively: 3.5; 3.9 and 4.0 mg after 3, 6, and 9 months of the experiment. However, the process of lung fibrosis when affected by antigorite from Nasławice was slower than under effects of antigorite from Szklary, which may result from almost 10 times fewer numbers of fibrous particles in the dust obtained from antigorite from Nasławice.