[Fibrogenous effect of silica dust from different soil deposits in Poland]

The fibrogenous effect of the dusts from 4 samples of siliceous earth collected from different deposits in Poland has been evaluated. The studies have been carried out on white rats (males), by single intratracheal administration of 50 mg dust suspended in 0,6 cm3 of the physiological solution of NaCl. After 3 months the animals were decapitated to determine: the weight of wet mediastinal lymph nodes, the weight of wet lungs, lipids and hydroxyproline content in lungs. The hydroxyproline content was the primary index of the fibrogenous action. The results demonstrated that from among the 4 samples of siliceous earth, the siliceous earth from Piotrowice exhibited the greatest fibrogenous effect. The hydroxyproline content in rats' lungs, resulting from the effect of siliceous earth from Piotrowice was nearly 5-fold that in the animals administered with the dusts of the remaining siliceous earth samples. The mining and processing of mineral raw materials are usually related to a great dustiness in work environment, therefore deposits of the siliceous earth of the weakest fibrogenous activity should be mined to reduce the risk of the development of nonspecific diseases of respiratory tract, lungs, and pneumoconiosis in the exposed workers.