Talc pneumoconiosis

Our plain-English summary of Talc pneumoconiosis, by A.I. McLAUGHLIN, E. Rogers, K.C. Dunham (British Journal of Industrial Medicine, 1949).

The study

• Authors: A.I. McLAUGHLIN, E. Rogers, K.C. Dunham
• Journal: British Journal of Industrial Medicine
• Published: 1949;6(3):184-94
• Cited by: 30 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 (J-M no. 001934).

In plain English

This was a case report of a 51-year-old man who worked thirty-seven years in a rubber tyre factory, where talc was blown through tyres and patted onto them. He died in August 1946. The causes of death were congestive heart failure from rheumatic endocarditis, and pneumoconiosis. His lungs contained nodules of loosely woven fibrous tissue and small numbers of "curious bodies" resembling, but not completely identical with, asbestosis bodies. Asbestos had never been used in the factory. Mineral extracted from the lung was almost entirely straight fibres up to 10 microns long, which x-ray powder photographs confirmed as talc. An exhaustive search for amphibole fibres showing inclined extinction, an optical feature, found none. X-ray analysis suggested less than 0.06 per cent free silica in the lung, by dry weight. Most of his exposure was to Norwegian talc. That talc was mostly platy, but its finest material had many fibres like those in the lung, along with very minor tremolite. The authors concluded that talc pneumoconiosis and asbestosis are likely similar diseases, though asbestos appears more actively fibrogenic. The article also reviewed earlier reports.

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 (clinical history, x-rays, autopsy lung pathology, chemical and mineralogical analysis of lung dust and factory talcs), with a review of the literature on talc pneumoconiosis
• Who was studied: One man, aged 51, who had worked in a rubber tyre factory for thirty-seven years. He was followed by the County Tuberculosis Officer for Wiltshire and died in August 1946; his lungs were examined after death.
• Exposure: Talc dust from work on a tyre-extruding machine, where talc (French chalk) was blown through tyres and patted onto them. The talc was Norwegian up to 1939. For his last five years it was 'French chalk substitute' and Canadian talc, but the bulk of his exposure was Norwegian talc. Asbestine, a fibrous variety of talc, was used in the factory from time to time, but not on the extruding machines.
• Main results:
  • The lung nodules consisted of loosely woven fibrous tissue.
  • Small numbers of 'curious bodies' were found in all lung sections; they resembled, but were not completely identical with, asbestosis bodies.
  • Further inquiry into the man's work history found that asbestos had never been used in his factory.
  • Mineral residue extracted from the lung consisted almost entirely of straight fibres.
  • The fibres extracted from the lung were up to 10 microns in maximum length.
  • An exhaustive search of the lung residue for amphibole fibres showing inclined extinction (an optical property seen under polarized light) found no such fibres.
  • X-ray powder photographs confirmed that the mineral in the lung was talc.
  • No carbonate particles were found in the lung residue.
  • X-ray analysis of the lung ash suggested less than 0.06 per cent free silica in the lung, measured by the lung's dry weight.
  • The Norwegian factory talc was mostly platy, but its finest material contained a high proportion of fibres exactly like those in the lung.
  • The Norwegian talc contained very minor quantities of tremolite and other minerals. A separate mineralogical report on a sample supplied by the factory owners stated that tremolite was common among the minor constituents.
  • The talc in the lung could have come from either the Norwegian or the Canadian talc. No minerals characteristic of the 'French chalk substitute' were found in the lung.
  • Fine grinding of talc produced material with individual fibre form. This included talc from Corriecharmaig, Perth, which formed in rock containing no amphibole.
• The authors' conclusion: The authors concluded that talc pneumoconiosis and asbestosis are likely similar diseases, though asbestos appears to be more actively fibrogenic (fibrosis-producing) than talc.
• Limitations the authors state:
  • The chemist who analysed the lung said that, because of technical difficulties, the total silica and free silica figures from the chemical analysis were probably too high.
  • The authors noted that complete surveys of the rubber industry had not yet been made.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Talc and vermiculite.

Medical terms in this study, explained in our Lexicon: Talc, Pneumoconiosis.

Related studies

• Talc pneumoconiosis: a report of six patients with postmortem findings — M. Kleinfeld, C.P. Giel, et al. (1963)
• Talc pneumoconiosis in the textile industry — B. Mann, J.B. Deasy (1954)
• Mixed pneumoconiosis: silicosis, asbestosis, talcosis, and berylliosis — G.J. Mark, C.B. Monroe, et al. (1979)
• Talc dust pneumoconiosis — A. Berner, B. Gylseth, et al. (1981)
• Pneumoconiosis and malignant mesothelioma in a family operated metal casting business that used industrial talc from New York state — M.M. Finkelstein (2013)
• Pulmonary ventilatory function in talcosis of lung — M. Kleinfeld, J. Messite, et al. (1964)

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