The effect of asbestos-cement, cement and asbestos dusts on the lungs of rats.

Experimental coniosis was induced by intratracheal administration to rats of 25 mg or 50 mg of Portland cement, asbestos-cement, as well as chrysotile and crocidolite asbestos. The rats were sacrificed 90, 165 and 180 days after dust administration. The weight of wet lungs and hydroxyproline content in lungs were determined. Statistically significant lower values of fibrogenic effects indices following cement dust administration, as compared to those indices for the other dusts, were found. On the other hand, no significant differences were found between fibrogenic effects indices for asbestos-cement containing approx. 13% of asbestos and pure asbestos dusts (chrysotile or crocidolite). Furthermore, it seems that the duration of dust action is more important than the dust dose in the development of fibrogenic asbestosis.