title: The effects of the inhalation of asbestos in rats.
abstract: Two experiments in which SPF Wistar rats were exposed by inhalation to dust clouds of the UICC standard reference samples for periods of between one day and 2 years are described. All the samples of asbestos produced asbestosis which continued to progress after removal from exposure but only a little fibrosis was observed in control rats. Lung tumours, ranging in severity from adenomata to squamous carcinomata, were produced by all samples but in the controls there were only a few adenomata and none of the more serious tumours. Of the 20 tumours which metastasized, 16 occurred after exposure to one or other of the 2 chrysotile samples. In addition, a total of 11 mesotheliomata occurred, 4 of which were with crocidolite and 4 with Canadian chrysotile. Two of the mesotheliomata occurred with only one day's exposure to asbestos. There was a positive association between asbestosis and lung tumours.
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000209:etiology; D000236:Adenoma / Q000209:etiology; D000818:Animals; D001195:Asbestosis / Q000150:complications* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000209:etiology; D004305:Dose-Response Relationship, Drug; D004391:Dust; D004781:Environmental Exposure; D005260:Female; D006651:Histocytochemistry; D008175:Lung Neoplasms / Q000209:etiology* / Q000473:pathology; D008325:Mammary Neoplasms, Experimental / Q000209:etiology; D008654:Mesothelioma / Q000209:etiology; D008854:Microscopy, Electron; D009362:Neoplasm Metastasis; D009374:Neoplasms, Experimental / Q000209:etiology; D051381:Rats; D013997:Time Factors
chemical_list: D004391:Dust