Asbestos carcinogenesis

Pulmonary asbestos body counts and electron probe analysis of asbestos body cores in patients with mesothelioma: a study of 25 cases

Malignant mesotheliomas of the pleura and peritoneum are well-recognized risks of asbestos exposure. We determined the asbestos body content of the lungs from 24 cases of malignant mesothelioma (19 pleural, five peritoneal) and compared such to the content of lungs from 50 consecutive adult autopsies and four cases of overt asbestosis using a Clorox-digestion concentration technique. The cores of 90 asbestos bodies were examined by energy dispersive x-ray analysis and compared with similar data from 120 standard asbestos fibers and 20 fiberglass fibers. The malignant mesothelioma patients had asbestos body counts intermediate between those of the general population and those of patients with asbestosis, although some of the mesothelioma cases overlapped with the general population. These latter cases often lacked an identifiable occupational exposure to asbestos. EDXA studies demonstrated an amphibole core in 88 of the 90 asbestos bodies (amosite or crocidolite in 80 of 88, anthophyllite or tremolite in eight of 88), and chrysotile in two instances.

Crystal faces and cleavage planes in quartz as templates in biological processes

Some species of minerals, when comminuted and aerosolized in the form of respirable-size particulate dusts, are recognized as capable of producing disease in man after their inhalation. Comprehensive listings of such agents are in the current literature (e.g. in Aponte, 1970; Langer & Mackler, 1972; Ehrenreich et al. 1973a, b) and many of these and their effects are well known and receive much attention. Asbestos fibres of all varieties, ampbibole and quartz contaminated talcum powders (see Rohl et al. 1976), fibrous amphiboles and their cleavage fragments which contaminate the ambient environment (e.g., the contamination of Lake Superior with cummingtonite-grunerite, as discussed in Bowes, Langer & Rohl, 1977), have been the subject of recent intensive investigations mostly due to their protential impact to large segments of the general population.