Pulmonary asbestos and dust content in East Anglia

Our plain-English summary of Pulmonary asbestos and dust content in East Anglia, by P.G. Stovin, P. Partridge (Thorax, 1982).

The study

• Authors: P.G. Stovin, P. Partridge
• Journal: Thorax
• Published: 1982;37(3):185-92
• Cited by: 5 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. 004858).

Abstract

Measurements were made of the asbestos fibre and dust content of samples from 96 surgically excised lungs; 42 necropsies on patients with lung cancer, 11 necropsies on patients with non-pulmonary malignancies, and 59 necropsies on patients without any malignant disease. The patients' ages ranged from 45 to 74 years at the time of study. None of the patients had asbestosis. The distribution of fibres and dust content of the lungs showed a log-normal distribution. There was no significant difference in fibre counts or dust content between men and women, and between lung cancer and non-cancer patients. The only group with an association with a high asbestos fibre count was four necropsy cases of pleural mesothelioma. There was no significant relationship between asbestos fibre count and dust content of the lung. The present data suggest that asbestos fibre counts below 100,000 per gram of dried lung are not related to specific asbestos disease, although in the surgical cases who were closely questioned on their residential and occupational histories most of those with fibre counts above 30,000 per gram dried lung had had occasions of definite or very likely asbestos exposure.

In plain English

This study measured asbestos fibres and other dust in lung tissue from people in Cambridgeshire and adjacent counties in East Anglia. It covered 96 lungs removed at surgery, all but four for lung cancer, and 112 lungs examined at necropsy (autopsy), from people aged 45 to 74. None showed asbestosis. Coated and uncoated asbestos fibres longer than 8 micrometres were counted by microscope. The article does not identify fibre types. Fibre counts did not differ significantly between men and women or between lung cancer and non-cancer cases, and did not rise with age. Four necropsy cases of pleural mesothelioma had 14 400 to 1 780 700 fibres per gram of dried lung (median 116 200), significantly more than any other group. The authors tentatively concluded that counts up to about 30 000 per gram probably reflected occasional non-occupational exposure, that higher counts were likely occupational, and that above about 100 000 asbestos-related lung disease was likely. They reported appreciable differences between the separately counted surgical and necropsy series, and up to eight-fold variation between parts of one lung.

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: Measurement of asbestos fibre counts and dust content in lung tissue from surgically removed lungs and necropsy lungs, with occupational and residential histories taken for the surgical patients
• Who was studied: 96 surgical cases and 112 necropsy cases, all aged 45 to 74, from Cambridgeshire and parts of adjacent counties (East Anglia). Four younger surgical cases were excluded. All but four surgical cases had bronchogenic carcinoma. Of the 112 necropsy cases, 59 had no malignant disease, 42 had lung cancer, 4 had mesothelioma and 7 had non-pulmonary cancers.
• Exposure: Asbestos fibres (coated and uncoated, longer than 8 micrometres) counted by phase contrast microscopy after potassium hydroxide digestion, plus non-asbestos dust weight, per gram of dried lung. The article does not identify fibre types.
• Main results:
  • The four necropsy cases of pleural mesothelioma had fibre counts from 14 400 to 1 780 700 per gram of dried lung, with a median of 116 200.
  • There were no significant differences in fibre counts or dust content between lung cancer and non-cancer cases.
  • The authors found no evidence that a median count of 11 000 fibres was related to the presence of lung cancer.
  • There was no significant difference in fibre counts or dust between males and females.
  • In both the surgical and necropsy cases, asbestos fibre and dust content did not increase with age.
  • None of the lungs studied showed the interstitial fibrosis of asbestosis.
  • The necropsy cases with hyaline fibrotic pleural plaques (nine men and one woman) had a median fibre count of 12000 per gram of dried lung, not different from the carcinoma and non-carcinoma cases.
  • Among the 16 surgical cases with the highest fibre counts, the most frequent occupation was building labourer with substantial demolition work.
  • Fibre counts and dust content did not differ significantly between squamous cell carcinoma cases (58 surgical, 15 necropsy) and adenocarcinoma cases (20 surgical, 17 necropsy).
  • There was no correlation between asbestos fibre count and dust content of the lungs.
• The authors' conclusion: The authors tentatively concluded that non-occupational exposure in East Anglia probably represents occasional short episodes giving counts up to about 30 000 fibres per gram of dried lung. They concluded that above this level exposure is likely to be occupational, and above about 100 000 asbestos-related lung disease is likely.
• Limitations the authors state:
  • The surgical and necropsy series were counted independently by the two authors, and the counts differed appreciably despite standardised methods.
  • Uncoated fibres were probably undercounted in the necropsy series.
  • Fibre counts varied between different segments of the same lung.
  • Smoking and occupational histories were incomplete for necropsy patients.
  • Even with detailed questioning, patients may not remember exposure or may not have known what they worked with.

Topics

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

Medical terms in this study, explained in our Lexicon: Lung Cancer, Autopsy, Pleural Mesothelioma, Asbestos Exposure.

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