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

Our plain-English summary of Scanning electron microscopy and x-ray microanalysis of mineral deposits in lungs of a patient with pleural mesothelioma, by E.M. Ophus, G. Mowé, K.K. Osen, et al (British Journal of Industrial Medicine, 1980).

The study

• Authors: E.M. Ophus, G. Mowé, K.K. Osen, B. Gylseth
• Journal: British Journal of Industrial Medicine
• Published: 1980;37(4):375-81
• Type of article: Case report
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy.

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 10(6) fibres per gram of dry tissue no significant lung fibrosis was found.

In plain English

This was a report on one patient, an insulation worker who died of pleural mesothelioma in 1978. From 1935 to 1952 the patient did insulation work in industry and shipyards and was exposed to asbestos (mainly amphibole minerals), man-made mineral fibres, cork and diatomaceous earth. At autopsy the tumour was of pure epithelial type and involved the pleura on both sides. The authors ashed lung tissue at low temperature and examined it by scanning electron microscopy with x-ray microanalysis. The mean concentration was 33 million fibres per gram of dry lung. It was significantly higher in one sample taken 2 to 3 cm from the pleura (66 million). Of the fibres, 92% were identified as amphibole asbestos. Chrysotile was not detected, but the authors said it could not be excluded because very thin fibres could not be identified. In the 83% of asbestos bodies whose core could be identified, only amphiboles, mainly crocidolite, were found. Despite this fibre burden, no significant lung fibrosis was found. Diatom shell fragments and titanium-containing particles were also seen. The authors concluded that fibre concentration may vary between regions within the same lung segment.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report with laboratory analysis of lung tissue (autopsy, scanning electron microscopy and energy dispersive x-ray microanalysis of low temperature ashed lung tissue)
• Who was studied: One insulation worker, born 1920, who did insulation work in industry and shipyards from 1935 to 1952 and died of pleural mesothelioma in March 1978. Two lung slices, each divided into three pieces, were analysed (six samples).
• Exposure: 17 years of insulation work with asbestos (mainly amphibole minerals), man-made mineral fibres, cork and diatomaceous earth. No occupational asbestos exposure was recorded after 1952. The patient also smoked 10-15 cigarettes a day from age 15.
• Main results:
  • Mean fibre concentration in this patient's lung was 33 x 10^6 fibres per gram of dry tissue, yet no significant lung fibrosis was found.
  • Concentrations varied by region. In the six samples they ranged from 22 to 32 x 10^6 fibres per gram, except the central sample of slice 2 (2-3 cm from the pleura), which had 66 x 10^6 (range 55-82). This was described as significantly larger.
  • 92% of fibres were identified as amphibole asbestos by x-ray microanalysis. Chrysotile was not detected.
  • The central fibre could not be identified in 17% of asbestos bodies. In the remaining 83%, where the core could be identified, only amphibole minerals, mainly crocidolite, were found.
  • Coated fibres (asbestos bodies) made up 7.1% of fibres in this patient, according to the discussion.
  • About 90% of the central fibres in asbestos bodies were longer than 5 micrometres, compared with 30% of naked fibres. Size distributions were based on 1459 naked fibres and 114 central fibres.
  • Few fibres were found in the thickened and calcified pleura. This indicated pleural fibre concentrations at least one order of magnitude less than in lung tissue.
  • At autopsy the tumour involved the visceral and parietal pleura on both sides and was of pure epithelial character.
  • Fragments of diatom shells and particles containing titanium (presumably titanium dioxide pigments) were also found in the lung tissue.
• The authors' conclusion: The authors concluded that fibre concentration may vary between regions within the same lung segment. They said whole slices of both lungs should be sampled in comparative studies. They also stated that the significance of the other minerals found for the development of the mesothelioma is uncertain.
• Limitations the authors state:
  • Fibres thinner than about 0.1 micrometre could not be identified by x-ray microanalysis, so the true proportion of asbestos fibres may have been higher.
  • The presence of chrysotile cannot be excluded, because fibres too thin to identify may have been chrysotile degraded in the body or during sample preparation.
  • In 17% of asbestos bodies the central fibre could not be identified because of the iron signal from the coating.
  • The authors could not prove the presence of hyaluronic acid, a characteristic feature of such tumours. They suggested prolonged formalin fixation as a possible reason.
  • Samples came from within one lung segment. Greater variation might exist between different segments or lobes.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Scanning Electron Microscopy (SEM), Pleural Mesothelioma, Insulator, Asbestos Bodies, Amphibole Asbestos, Fibrosis.

Related studies

• Pulmonary mineral dust. A study of ninety patients by electron microscopy, electron microanalysis, and electron microdiffraction — J.P. Berry, P. Henoc, et al. (1976)
• A technical comparison of evaluating asbestos concentration by phase-contrast microscopy (PCM), scanning electron microscopy (SEM), and analytical transmission electron microscopy (ATEM) as illustrated from data generated from a case report — R.F. Dodson, S.P. Hammar, et al. (2008)
• Lung dust content in idiopathic pulmonary fibrosis: a study with scanning electron microscopy and energy dispersive x ray analysis — E. Monsó, J.M. Tura, et al. (1991)
• Study of inorganic particles, fibers, and asbestos bodies by variable pressure scanning electron microscopy with annexed energy dispersive spectroscopy and micro-Raman spectroscopy in thin sections of lung and pleural plaque — C. Rinaudo, A. Croce, et al. (2010)
• Environmental scanning electron microscopy technique to identify asbestos phases inside ferruginous bodies — A. Croce, M. Musa, et al. (2013)
• Comments on Dodson et al., A technical comparison of evaluating asbestos concentration by phase contrast microscopy (PCM), scanning electron microscopy (SEM), and analytical transmission electron microscopy (ATEM) as illustrated from data generated from a case report — V.L. Roggli, T.A. Sporn, et al. (2008)

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