Asbestos: some nonradiological aspects

Our plain-English summary of Asbestos: some nonradiological aspects, by P.J. Lawther (Proceedings of the Royal Society of Medicine, 1971).

The study

• Author: P.J. Lawther
• Journal: Proceedings of the Royal Society of Medicine
• Published: 1971;64(8):833-4
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 002445).

In plain English

This was a short introductory note for a 1970 Section of Radiology meeting on asbestosis and allied diseases. It was not a new study but an aide-memoire. Chrysotile made up about 93% of world production of three million tons, and amosite, crocidolite and anthophyllite were amphibole types. It listed exposure sources including mining, insulation work, ship-breaking, demolition, electricians near laggers, and air pollution from brake linings. It stated that any type can cause asbestosis, which was becoming rare. Citing Doll (1965), it stated that lung cancer is found more often among workers exposed over several years to asbestos of any type than in the general population. It reported Selikoff and colleagues' point that lung cancer was found only in asbestos workers who also smoked. It described Wagner and colleagues' 1960 association between crocidolite and pleural mesothelioma, including in people living near mines. It said peritoneal mesothelioma may also be associated with asbestos, and that asbestos bodies show past exposure, not asbestosis. The author concluded, citing Legge, that a safe substitute should be used where possible.

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: Brief introductory note (narrative overview citing other published work); not an original study
• Exposure: Asbestos in general. Chrysotile (serpentine) and the amphiboles amosite, crocidolite and anthophyllite. Exposure sources named: mining, crushing, carding, spinning, thermal insulation, ship-breaking, demolition, electricians near laggers, and community air pollution from factories, waste disposal and abrasion of brake linings and clutch facings.
• Main results:
  • Chrysotile was stated to make up about 93% of the world's production of three million tons of asbestos.
  • The author stated that inhaling any of the types can cause asbestosis. Because of improved occupational hygiene following legislation, the disease was described as becoming rare.
  • Impaired gas transfer in the lung was stated to be detectable before radiological signs of fibrosis appear.
  • Citing Doll (1965), the author stated that lung cancer is found more often among workers exposed over several years to asbestos of any type than in the general population. Citing Knox et al. (1968), the author stated that this excess was diminishing.
  • Citing Selikoff et al. (1969), the author stated that lung cancer is found only in asbestos workers who also smoke, and suggested this may be true synergism.
  • Citing Wagner et al. (1960), the author described an association between pleural mesothelioma and crocidolite exposure, including exposure acquired by living near mines or works processing crocidolite.
  • Citing Newhouse & Thompson (1965), a similar association with occupation or with residence near asbestos works was reported in Britain. The author stated that exposure need be only minute and that tumours may not appear for forty years.
  • The author suggested that peritoneal mesothelioma may also be associated with asbestos exposure. Citing Hammond et al. (1965), the author mentioned reports of higher incidence of gastrointestinal cancer among asbestos workers.
  • Asbestos bodies were described as showing only past exposure, not asbestosis. The author stated that most people's lungs contain them at post-mortem, even without occupational exposure.
  • In work on the carcinogen in asbestos, Commins & Gibbs (1969) were cited as finding that one impurity in standard samples came from an anti-oxidant in the polythene bag in which the samples were stored.
• The authors' conclusion: The author concluded, citing Legge's aphorism, that while research proceeds a safe substitute should be used where possible.
• Limitations the authors state:
  • The author stated that a full review of the chemistry, physics, mineralogy, uses and effects of asbestos was not intended in this introductory note.

Topics

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

Related studies

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• Carcinogenic industrial air pollution and postmenopausal breast cancer risk in the National Institutes of Health AARP Diet and Health Study — J.M. Madrigal, C.N. Pruitt, et al. (2024)
• The role of threshold limit values in U.S. air pollution policy — J.C. Robinson, D.G. Paxman (1992)
• Area and personal airborne exposure during abatement of asbestos-containing roofing material — J.H. Lange, K.W. Thomulka (2000)
• Asbestos air pollution — I.J. Selikoff, W.J. Nicholson, et al. (1972)

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