Exposure to asbestos dust and diffuse pleural mesotheliomas

Our plain-English summary of Exposure to asbestos dust and diffuse pleural mesotheliomas, by J.G. Thomson (British Medical Journal, 1963).

The study

• Author: J.G. Thomson
• Journal: British Medical Journal
• Published: 1963;1(5323):123
• Cited by: 11 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. 001575).

Summary of the article

In this letter, the author, writing from the Department of Pathology at the University of Capetown Medical School, responded to earlier correspondence by Smithers and colleagues and by McCaughey and colleagues on the association between malignant pleural mesothelioma and exposure to asbestos dust. He summarised a recent article in which he had described a condition he called basal, or limited, asbestosis. In this condition the lesion was largely confined to the lung bases, produced no signs or symptoms, and was usually overlooked at necropsy unless sections from the lung bases were examined. He suggested that the lesion might locally reach a carcinogenic concentration and, because it did not shorten life, might later prove to produce more malignant tumours than classical asbestosis. In three years in the necropsy service of a teaching hospital he had encountered six malignant mesotheliomas, three pleural and three peritoneal, and basal asbestosis was demonstrated in five. In 1961, at four centres in the United States, he found basal asbestosis in nine of 15 pleural and peritoneal mesotheliomas with adequate lung for study, and it had been overlooked in all but two. He noted that world asbestos consumption had risen from 500,000 tons in 1942 to 2,400,000 tons in 1961. He cited necropsy evidence that a large and increasing percentage of the population inhaled asbestos fibres, and wondered whether in 20 years asbestos-induced mesothelioma might be as common as lung cancer.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This is a letter to the editor, not a research paper. It replied to two earlier letters on the association between malignant pleural mesothelioma and asbestos dust exposure. The author summarized their own earlier article describing "basal asbestosis", a lesion more or less confined to the lung bases. The author stated it causes no pulmonary signs or symptoms and is usually overlooked at necropsy, missed even microscopically unless lung-base sections are examined. Over three years at a teaching hospital's necropsy service, six malignant mesotheliomas were found (three pleural, three peritoneal); five showed basal asbestosis. In 1961, at four United States centres, the author found basal asbestosis in nine of 15 pleural and peritoneal mesothelioma cases with adequate lung. In all but two, it had been overlooked. Occupational asbestos exposure was mentioned in very few cases, which the author called of no significance unless patients or relatives are asked directly. The author suggested basal asbestosis may later prove to produce more malignant tumours than classical asbestosis. The author wondered whether in 20 years asbestos-induced mesothelioma might become as common as lung cancer then was.

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: Letter to the editor (correspondence) summarizing the author's own earlier necropsy observations
• Who was studied: Necropsy cases of malignant mesothelioma: six cases over three years at a teaching hospital (not named), and 15 pleural and peritoneal mesothelioma cases with adequate lung seen at four centres in the United States in 1961
• Exposure: Asbestos dust, assessed through the finding of basal asbestosis in the lungs at necropsy. No fiber type was named.
• Main results:
  • Among the six malignant mesothelioma cases from the teaching hospital necropsy service (three pleural, three peritoneal), basal asbestosis was demonstrated in five
  • In 1961 at four United States centres, basal asbestosis was found in nine of 15 pleural and peritoneal mesothelioma cases with adequate lung for study
  • In all but two of the United States cases with basal asbestosis, the condition had been overlooked
  • The author stated that basal asbestosis produces no pulmonary signs or symptoms, is usually overlooked at necropsy, and will be missed even microscopically unless sections from the lung bases are examined
  • The author reported that world annual consumption of asbestos rose from 500,000 tons in 1942 to 2,400,000 tons in 1961
• The authors' conclusion: The author suggested that basal asbestosis may later be found to produce more malignant tumours than classical asbestosis. The author speculated that, as inhaled fibres collect at the lung bases, asbestos-induced mesothelioma might in 20 years be as common as lung cancer was at the time.
• Limitations the authors state:
  • Occupational exposure to asbestos was mentioned in very few of the cases. The author noted this is of no significance unless patients or relatives are asked directly.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Pathology, Autopsy, Carcinogenic, Malignant Mesothelioma, Peritoneal Mesothelioma, Mesothelioma, Lung Cancer.

Related studies

• Diffuse mesothelioma and exposure to asbestos dust in the Merseyside area — W.G. Owen (1964)
• Characterization of the dust/smoke aerosol that settled east of the World Trade Center (WTC) in lower Manhattan after the collapse of the WTC 11 September 2001 — P.J. Lioy, C.P. Weisel, et al. (2002)
• Dust exposure and mortality in chrysotile mining, 1910-75 — J.C. McDonald, F.D. Liddell, et al. (1980)
• Enhanced generation of free radicals from phagocytes induced by mineral dusts — V. Vallyathan, J.F. Mega, et al. (1992)
• Acute eosinophilic pneumonia in a New York City firefighter exposed to World Trade Center dust — W.N. Rom, M. Weiden, et al. (2002)
• Increased mortality in COPD among construction workers exposed to inorganic dust — I.A. Bergdahl, K. Torén, et al. (2004)

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