Three Cases Of Asbestosis

Our plain-English summary of Three Cases Of Asbestosis, by J. Frost (1950).

The study

• Author: J. Frost
• Published: Ugeskrift Fur Laeger 112(37):1284-1289, September 14 (1950)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library, J-M no. 004293. The article is still under copyright, so we describe it here rather than post it.

In plain English

This Danish article, from the Factory Inspectorate and the occupational medicine clinic of Rigshospitalet in Copenhagen, described three cases of asbestosis. Case 1 was a weaver, born in 1895, who had worked for many years at a factory that wove asbestos, including for brake bands. Case 2 was a shipyard worker who from 1935 insulated pipes using asbestos cord and asbestos cloth. Case 3 was a labourer, born in 1908, who worked at a factory making the base material for asbestos floors from powdered asbestos and magnesia cement. Symptoms began after 2, 6 and 4 years of work respectively. After 17, 10 and 10 years of exposure the workers left or cut back their asbestos work. Case 1 died 3 years later. Case 2 was almost 100% disabled, and case 3 was severely disabled. Cases 1 and 2 had earlier been diagnosed with dry pleurisy and bronchitis. Case 3's X-rays also showed fine nodular, silicosis-like changes, which the author suggested might come from the very finely powdered asbestos. The author concluded that knowing the disease and taking a careful work history are needed to recognise milder cases on X-ray. The asbestos types used were not known.

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 reports (three cases of asbestosis), with a discussion of published literature
• Who was studied: Three male workers in Denmark: a weaver born in 1895, a shipyard worker, and a labourer born in 1908. They were reported by the Factory Inspectorate and Rigshospitalet's occupational medicine clinic.
• Exposure: Case 1: weaving of asbestos at a factory, including for brake bands. Case 2: shipyard pipe insulation with asbestos cord and asbestos cloth, in later years also rockwool and glass wool. Case 3: making the base material for asbestos floors from a mixture of powdered asbestos and magnesia cement. The asbestos types used could not be established.
• Main results:
  • Case 1 worked for many years at a factory with large-scale asbestos weaving, including for brake bands, and had tended a weaving machine since 1928
  • Case 3 worked with a material made of a mixture of powdered asbestos and magnesia cement
  • Subjective symptoms appeared after 2, 6 and 4 years respectively in the three cases. The corresponding exposure times, after which symptoms led them to leave or cut back their asbestos work, were 17, 10 and 10 years.
  • Case 1 died 3 years after stopping work. After a further 3 years of observation, case 2 was almost 100% disabled and case 3 was severely disabled.
  • Cases 1 and 2 had been diagnosed with dry pleurisy (pleuritis sicca) and bronchitis, although their X-ray films were characteristic of asbestosis
  • In cases 1 and 2 the X-ray findings were the usual ones for asbestosis: diffuse fibrosis in the lower parts of both lung fields, with pleural thickening and reduced movement of the diaphragm
  • In case 3 the X-rays also showed fine nodular changes like those seen in silicosis. The diagnosis was made at the first X-ray examination, after 4 years of exposure.
  • In case 3, lung function testing gave a total capacity of 58% of the predicted value. The test was concluded to show severe, mainly pulmonary, functional impairment.
  • In case 3, exercise at 400 kgm/min caused a marked fall (8%) in arterial oxygen saturation, and the patient gave up after 2 minutes
  • Chronic cor pulmonale (strain on the right side of the heart) could not be shown clinically in any of the three cases
• The authors' conclusion: The author concluded that knowledge of the disease and a careful occupational history are necessary if milder cases are to be recognised by X-ray, for example in routine tuberculosis screening. The author also considered that such knowledge would probably have led to earlier diagnosis in these cases. The author suggested that the silicosis-like picture in case 3 may be explained by the very finely powdered asbestos, so that the mechanical effect of the asbestos needles was not prominent.
• Limitations the authors state:
  • The author could not obtain details of the asbestos types used, and there were no dust measurements from the relevant times
  • Case 1 was not autopsied
  • The author noted that the absence of ECG and X-ray signs of right-sided heart enlargement does not rule out cor pulmonale

Topics

Medical terms in this study, explained in our Lexicon: Pleurisy, Silicosis, Work History.

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