The Medical Risks Of Exposure To Asbestos

Our plain-English summary of The Medical Risks Of Exposure To Asbestos, by M.L. Newhouse (1967).

The study

• Author: M.L. Newhouse
• Published: Practitioner 199(191):285-293, September (1967)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library, J-M no. 001487. The article is still under copyright, so we describe it here rather than post it.

In plain English

This was a review for British general practitioners. It described the main types of asbestos (chrysotile, crocidolite, amosite and anthophyllite) and how workers and others were exposed. It then summarized published work on asbestosis, bronchial carcinoma, mesothelioma and gastro-intestinal tumours. Among the studies cited, a 1929 factory survey found about a third of workers had pulmonary fibrosis. Figures from Gilson (1966) showed fibrosis in 59 of 133 workers examined in 1929 and in 9 of 680 examined in 1964, a fall the author linked to satisfactory dust control. Ministry of Labour figures showed that about 50 per cent of patients certified with asbestosis died of bronchial carcinoma. A South African survey found that 32 of 33 mesothelioma patients had been exposed to crocidolite. In a retrospective London Hospital study of 76 mesothelioma patients, 24 (32%) had worked in asbestos factories, compared with 2 (3%) of a control series. The author concluded that managing the asbestos problem depends on preventing workers' exposure to harmful concentrations of 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: Narrative review of published research on the medical effects of asbestos exposure, written for general practitioners
• Who was studied: No study population of its own. The review covered published reports on asbestos workers (factory workers, laggers and insulators, miners) and people with household or neighbourhood exposure, mainly in the United Kingdom, with studies from South Africa, Canada and the United States.
• Exposure: Chrysotile, crocidolite, amosite and anthophyllite asbestos. Exposure in mining and milling, textile and other factories, lagging and insulation, building work, docks and transport, and non-occupational exposure from dust brought home on clothes or living near a mine or factory.
• Main results:
  • A 1929 Home Office survey of a factory (Merewether and Price, cited) found that approximately a third of the workers had pulmonary fibrosis.
  • Figures cited from Gilson (1966): in 1929, 59 cases of fibrosis among 133 examined (44.3%). In 1964, 9 cases among 680 examined (1.3%). The author stated that the group incidence had fallen in factories with satisfactory dust control.
  • The number of new asbestosis cases receiving compensation was increasing, and these cases came from both scheduled and unscheduled occupations (McVittie, cited).
  • Ministry of Labour figures (Buchanan, 1965, cited) showed that approximately 50 per cent of patients certified as suffering from asbestosis died of bronchial carcinoma.
  • In a cited study of men who had worked in one asbestos factory (Doll, 1953), all of the lung cancer cases studied were associated with asbestosis. The scanned text is too damaged to read the size of the excess risk.
  • Later work at the same factory (Knox et al., 1965, cited) suggested that the risk for those employed only after the regulations was much decreased.
  • The author wrote that there was sufficient evidence to postulate that bronchial carcinoma in patients with asbestosis is strongly related to asbestos exposure.
  • In a South African survey (Wagner et al., 1960, cited), 32 of the 33 mesothelioma patients had been exposed to crocidolite.
  • Of 116 mesothelioma patients identified in South Africa up to 1962, 110 had associations with the crocidolite mines, none with the amosite mine, and six with chrysotile mines.
  • In Canada, only three or four mesothelial tumours had been reported from the chrysotile mining area.
  • In three British series of mesothelioma patients (London, Belfast, Liverpool), totalling 168 patients, over two-thirds had had contact with asbestos.
  • In a retrospective study of 76 pleural or peritoneal mesothelioma patients at the London Hospital, 24 (32%) of the mesothelioma series had been employed in asbestos factories, compared with 2 (3%) of the control series. In the mesothelioma series, 9 (12%) had a relative who worked with asbestos, compared with 1% of the control series.
  • The time between first exposure and development of mesothelioma averaged thirty to thirty-five years.
  • A Ministry of Labour register held records of over 200 patients dying of pleural or peritoneal mesothelioma.
  • A cited study of over 1,500 insulation workers in New York (Selikoff and colleagues, 1964) reported raised rates of gastro-intestinal cancer, a finding supported by two other United States studies. The scanned text is too damaged to read the exact size of the excess.
• The authors' conclusion: The author concluded that successful management of the asbestos problem depends on preventing workers' exposure to harmful concentrations of dust, through engineering methods, codes of practice and reliable dust measurement.

Topics

Medical terms in this study, explained in our Lexicon: Chrysotile, Crocidolite, Amosite, Anthophyllite, Carcinoma, Mesothelioma, Pulmonary Fibrosis, Fibrosis.

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