Correlation between fibre content of the lung and disease in east London asbestos factory workers

Our plain-English summary of Correlation between fibre content of the lung and disease in east London asbestos factory workers, by J.C. Wagner, M.L. Newhouse, B. Corrin, et al (British Journal of Industrial Medicine, 1988).

The study

• Authors: J.C. Wagner, M.L. Newhouse, B. Corrin, C.E. Rossiter, D.M. Griffiths
• Journal: British Journal of Industrial Medicine
• Published: 1988;45(5):305-8
• Cited by: 56 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. 000285).

Abstract

The lungs from 36 past workers at an east London asbestos factory who had died from asbestos related disease were compared with lung tissue from 56 matched control patients being operated on in east London for carcinoma of the lung, correlating the severity of asbestosis and the presence of pulmonary carcinoma or mesothelioma of the pleura or peritoneum with an asbestos exposure index and type and amount of mineral fibre in the lungs. Asbestosis was associated with far heavier fibre burdens than mesothelioma. There was also a striking difference in the degree of asbestosis between the subjects with mesothelioma and those with carcinoma of the lung, the asbestosis being more severe in the latter. A further finding was that crocidolite and amosite were strongly associated with asbestosis, carcinoma of the lung complicating asbestosis, and mesothelioma, whereas no such correlation was evident with chrysotile or mullite. It is suggested that more emphasis should be placed on the biological differences between amphibole and serpentine asbestos fibre.

In plain English

The authors examined lung tissue from 36 former workers at an east London asbestos factory, which used crocidolite, chrysotile and amosite. The workers died between 1976 and 1984: 19 from mesothelioma (nine pleural, 10 peritoneal), 14 from lung carcinoma and three from asbestosis. For comparison, they used seemingly normal lung tissue from 56 lung carcinoma surgery patients who had never been occupationally exposed to asbestos. Fibres were counted and identified by electron microscopy. Workers with mesothelioma often had minimal or slight asbestosis, while those with lung carcinoma usually had moderate or severe asbestosis. Fibre content was heaviest in the asbestosis and lung cancer deaths and considerably lower in the mesothelioma deaths. On average, amphibole asbestos made up less than 6% of fibres in the controls but about 60% to 87% in the worker groups, with the lowest share in pleural mesothelioma. Crocidolite and amosite proportions rose with asbestosis severity, while chrysotile proportions fell. The authors concluded that chrysotile is the least harmful form of asbestos and that more emphasis should be placed on biological differences between amphibole and serpentine fibre.

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: Comparison of lung fibre content and disease: postmortem lung tissue from exposed factory workers versus surgical lung tissue from unexposed controls, analysed by analytical electron microscopy
• Who was studied: 36 past workers (25 men, 11 women) at an east London asbestos factory who died between 1976 and 1984 and whose lungs were submitted after coroners' postmortems. Controls were 56 patients (44 men, 12 women) operated on at the London Chest Hospital in 1983 to 1984 for carcinoma of the lung, never occupationally exposed to asbestos and generally living in east London. Mean ages were 62 (study cases, at death) and 61 (controls, at operation).
• Exposure: Manufacture of asbestos textiles, sectional asbestos piping and other asbestos products before the 1969 Asbestos Regulations. Crocidolite was used until the late 1950s, and chrysotile and amosite until the factory closed in 1968. Exposure was graded 1 to 6 by job, and an exposure index was calculated as exposure grade multiplied by months worked.
• Main results:
  • Among the 36 factory workers there were 19 deaths from mesothelioma (9 pleural, 10 peritoneal), 14 from carcinoma of the lung, and 3 from asbestosis.
  • Workers with mesothelial tumours often showed minimal or slight asbestosis.
  • Workers dying of carcinoma of the lung usually showed moderate or severe asbestosis.
  • The heaviest fibre content was found in workers dying of certified asbestosis and of lung cancer. Counts in the pleural and peritoneal mesothelioma cases were considerably lower. The mean fibre content of the three asbestosis lungs was nearly 50 times that of the controls.
  • The mean proportion of amphibole asbestos was less than 6% of fibres in the controls. In the worker groups it ranged from about 60% (pleural mesothelioma) to 87%. The text attributes 87% to the asbestosis lungs, but Table 3 gives asbestosis 17.7% amosite plus 60.1% crocidolite (77.8%). The lung carcinoma group, at 30.4% amosite plus 56.7% crocidolite, comes to about 87%.
  • The highest proportion of chrysotile was found in the control lungs. Pleural mesothelioma lungs had less chrysotile than the controls.
  • In the workers, proportions of crocidolite and amosite increased with severity of asbestosis, while proportions of chrysotile and non-asbestos fibres decreased.
  • By exposure index there was no constant relation, but amosite and crocidolite proportions tended to rise with higher indices. Chrysotile formed less than 1% of total fibres in the 10 workers with the highest exposure index.
• The authors' conclusion: The authors concluded that chrysotile is the least harmful form of asbestos and that more emphasis should be placed on the different biological effects of amphibole and serpentine asbestos fibre. They considered it more likely that chrysotile plays only a minor part in causing asbestos-related diseases.
• Limitations the authors state:
  • The authors noted that the difference in asbestosis severity between mesothelioma and lung carcinoma cases may have been subject to referral bias: all mesotheliomas are likely to be referred, while minor asbestosis in carcinoma cases may be overlooked at necropsy. They judged such bias unlikely in asbestos factory workers.
  • The authors acknowledged that damage might have been caused by chrysotile fibres that later disappeared from the lung, though they considered this less likely than chrysotile playing only a minor part.

Topics

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

Medical terms in this study, explained in our Lexicon: Carcinoma, Mesothelioma, Pleura, Peritoneum, Asbestos Exposure, Crocidolite, Amosite, Chrysotile.

Related studies

• Correlation between fibre content of lung and disease in east London asbestos factory workers — R.M. Rudd (1989)
• Mortality from all cancers of asbestos factory workers in east London 1933-80 — G. Berry, M.L. Newhouse, et al. (2000)
• Mortality of factory workers in east London 1933-80 — M.L. Newhouse, G. Berry, et al. (1985)
• Correlation between fibre content of the lungs and disease in naval dockyard workers — J.C. Wagner, C.B. Moncrieff, et al. (1986)
• Pulmonary asbestos and dust content in East Anglia — P.G. Stovin, P. Partridge (1982)
• Malignant mesothelioma and duration of asbestos exposure: correlation with tissue mineral fibre content — V.L. Roggli (1995)

Browse more research in British Journal of Industrial Medicine, or return to medical research.