Scanning electron microscopy and x-ray microanalysis of mineral deposits in lungs of a patient with pleural mesothelioma.

Abstract

Scanning electron microscopy of lung tissue, ashed at low temperature, and obtained from an insulation worker who had died of pleural mesothelioma, showed the presence of numerous inorganic particles and fibres. A regional variation in fibre concentration in different tissue samples was found, and the size distribution of naked fibres and asbestos bodies was determined. By energy dispersive x-ray microanalysis the fibres were identified mainly as amphibole asbestos. This method also showed the presence of particles containing titanium and of fragments of diatom shells. Despite a mean concentration of 33 x 106 fibres per gram of dry tissue no significant lung fibrosis was found.The causal relation between asbestos exposure and pleural and peritoneal mesothelioma was established in 1960.1 Since then the increased incidence of mesothelioma in individuals exposed to asbestos has been widely documented.2 The relation to asbestos exposure may, however, be obscured by a long period between initial exposure and the appearance of the tumour. The dose required for the initiation of a mesothelioma is small, and may be acquired by non-occupational exposure to asbestos.3A relation between the lung asbestos burden and asbestos-related diseases has been suggested. [4][5][6] Identification and quantification of mineral particles in the lungs requires the use of microanalytical techniques.7 For in situ identification of inorganic substances in lung tissue-for instance, in the study of pneumoconiosis-scanning electron microscopy coupled with energy dispersive x-ray microanalysis has proved particularly useful.8 This instrumentation has also been used for quantitative analysis of mineral fibres in lung residues obtained by tissue degradation methods. Gylseth et a19 reported that low temperature plasma ashing is the most convenient and reliable technique for this purpose.In the present study we have used these methods

A method of direct particle deposition on a carbon planchet to study mineral dust in human lung by scanning electron microscopy

“…For particles larger than 0.1 pm, fibrous particle counts by our method at 600 or 1,500X would appear to underestimate the total number of particles, especially those under 5 pm in length and 0.5 pm in width. At 4,500 X the total mineral particle counts were comparable to those reported in the literature using different analytical processes, both in those with or without occupational exposure histories (Ashcroft and Heppelston, 1973;Churg, 1983;Gylseth et al, 1979;Ophus et al, 1980). Fibers larger than 5 pm, which may be underestimated by other methods USing sections (Abraham and Burnett, 19831, were readily detected by our method at this magnification (4,500).…”

Occupational asbestos exposure, lung-fiber concentration and latency time in malignant mesothelioma.

“…The diagnosis was, in all cases, based on autopsy. Five of the cases were recorded by the Can- (11,12,20,22). For all the cases autopsy reports and medical records were available.…”

It's elemental! Siliceous diatom frustules producing sarcoid‐like granulomas in the subcutis

“…Other harmful effects such as irritation of upper respiratory tract, skin irritation, and xerosis can also be the result of domestic use of DE as an insecticide, especially for bed‐bugs 47 . In the literature search, images of diatoms have been only shown in two cases: the first, in a shipyard worker who had died of pleural mesothelioma 48 and the second in a patient with delusional infestation 49 …”