Mixed pneumoconiosis: silicosis, asbestosis, talcosis, and berylliosis

Our plain-English summary of Mixed pneumoconiosis: silicosis, asbestosis, talcosis, and berylliosis, by G.J. Mark, C.B. Monroe, H. Kazemi (Chest, 1979).

The study

• Authors: G.J. Mark, C.B. Monroe, H. Kazemi
• Journal: Chest
• Published: 1979;75(6):726-8
• Type of article: Case report
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 002089).

Abstract

Mixed pneumoconiosis is pulmonary disease due to two or more inhaled mineral irritants. Chronic disease due to beryllium has not been a component of any described mixed pneumoconiosis. A man with occupational exposure to a combination of dusts developed severe pulmonary disease. Silicosis, talcosis, asbestosis, and berylliosis were all documented by an open biopsy of the lung. The varieties of mixed pneumoconiosis are summarized.

In plain English

This article is a case report of one man who died at 48 after six years of progressive respiratory insufficiency. After working as a window decorator until age 36, he spent six years at a metal-fabrication company. There he melted beryllium-copper ingots and made molds from a powdered mixture containing talc and asbestos, coated with silicone that he sanded. No air samples were taken, but he reported heavy dust exposure. He first noticed breathlessness at 42. Lung tests at 48 showed a restrictive defect: forced expiratory volume in one second was 29 percent of predicted and carbon monoxide diffusing capacity 12 percent. He died of bronchopneumonia, and no autopsy was done. A lung biopsy taken at 42 showed silicotic nodules, talc crystals and granulomas, and asbestos bodies (about one per high-power field). It also showed inflammation, with a beryllium content of 0.033 micrograms per gram of dried tissue against a laboratory normal of less than 0.020. The authors described a mixed pneumoconiosis of silicosis, talcosis, asbestosis and berylliosis. They wrote that chronic beryllium disease had not previously been reported with a second injurious dust.

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 of a single patient, with a brief discussion of other reported types of mixed pneumoconiosis
• Who was studied: one white man who had always lived in New England and smoked cigarettes occasionally. He died at age 48 after six years of progressive respiratory insufficiency.
• Exposure: Six years as a metal worker and mold-maker at a metal-fabrication company, after working as a window decorator until age 36. The job involved melting beryllium-copper ingots and pouring the molten metal into molds. He also made the molds from a powdered mixture containing talc and asbestos (fiber type not stated), coated with silicone that he sanded. He was the only person doing this job and used no dust protection.
• Main results:
  • The patient first noticed shortness of breath at age 42. Within two years he had quit work and depended on continuous supplemental oxygen.
  • At age 48, lung function tests showed a restrictive defect. Forced expiratory volume in the first second was 29 percent of predicted, vital capacity 33 percent, total lung capacity 42 percent and residual volume 61 percent of predicted.
  • The patient's carbon monoxide diffusing capacity was 12 percent of predicted.
  • The patient died of bronchopneumonia during a third hospitalization, six months after the second.
  • Silicosis was diagnosed from fibrous nodules in the open lung biopsy that contained numerous doubly refractile particles characteristic of silica. Similar nodules were found in a subcarinal lymph node.
  • Talcosis was diagnosed from needle-like crystals inside histiocytes and giant cells, which formed talcotic granulomas. Talc was the most abundant visible mineral.
  • Asbestosis was diagnosed from asbestos bodies, which averaged about one per high-power microscopic field. The authors stated these bodies matched the type seen in classic asbestosis rather than the ferruginous bodies seen in talcosis.
  • Chemical analysis found 0.033 micrograms of beryllium per gram of dried lung tissue. The authors called this moderately elevated; their laboratory's normal value is less than 0.020 micrograms per gram.
  • The authors stated the case met all six criteria used by the US Beryllium Case Registry to define chronic disease due to beryllium.
• The authors' conclusion: The authors concluded that the lung findings reflected the combined effects of four different agents, which they described as silicosis, talcosis, asbestosis and berylliosis. They stated that documenting a mixed pneumoconiosis requires histologic and chemical analysis of lung tissue, and that chronic beryllium disease had not previously been reported together with a second injurious dust.
• Limitations the authors state:
  • No air samples were taken at the workplace.
  • The heavy dust exposure was reported by the patient himself.
  • No autopsy was performed.
  • The authors noted that the interstitial lymphocytic infiltrate used to support the beryllium diagnosis is seen in many lung conditions.

Topics

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

Medical terms in this study, explained in our Lexicon: Pneumoconiosis, Silicosis, Occupational Exposure, Biopsy.

Related studies

• Pulmonary ventilatory function in talcosis of lung — M. Kleinfeld, J. Messite, et al. (1964)
• Talc pneumoconiosis: a report of six patients with postmortem findings — M. Kleinfeld, C.P. Giel, et al. (1963)
• Talc pneumoconiosis — A.I. McLAUGHLIN, E. Rogers, et al. (1949)
• Talc pneumoconiosis in the textile industry — B. Mann, J.B. Deasy (1954)
• Pulmonary granulomatous reaction: talc pneumoconiosis or chronic sarcoidosis? — P. Tukiainen, J. Nickels, et al. (1984)
• Silicosis, asbestosis, and cancer of the lung — W.C. Hueper (1955)

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