Mesothelioma induced by intrapleural injection of different types of fibres in rats; synergistic effect of other carcinogens.
Intrapleural injections of 20 mg of various mineral fibres were made to rats. Three types of fibres (chrysotile, crocidolite and glass fibres) were untreated; other chrysotile fibres were leached to different degrees. The results show that chrysotile is the most toxic of the three: animals died sooner and presented mesotheliomas earlier. With increased leaching, toxicity and carcinogenic effect decreased. Crocidolite is less toxic than untreated chrysotile but later produces as many mesotheliomas; with glass fibres, some mesotheliomas are observed. Small groups of animals were exposed to two types of irradiation before intrapleural injection of 2 mg of chrysotile. Whole-body irradiation was delivered to a third group of animals which were given asbestos-contaminated food. The paper analyses the synergistic action of these two insults.
D000818:Animals; D001194:Asbestos / Q000008:administration & dosage / Q000009:adverse effects*; D005898:Glass; D007267:Injections; D008175:Lung Neoplasms / Q000209:etiology; D008654:Mesothelioma / Q000209:etiology*; D009502:Neutrons; D010997:Pleural Neoplasms / Q000209:etiology*; D011886:Radon / Q000009:adverse effects; D051381:Rats; D013997:Time Factors
D001194:Asbestos; D011886:Radon