Health Hazards Of Asbestos

Our plain-English summary of Health Hazards Of Asbestos, by C.W. Stacy, D.R. Bowman (1977).

The study

• Authors: C.W. Stacy, D.R. Bowman
• Published: Environmental Health 85(11): 236-238, November (1977)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library, J-M no. 004434. The article is still under copyright, so we describe it here rather than post it.

In plain English

This article is a review, not an original study. The supplied text is bylined J.C. Gilson, not the cited authors. The author summarized diseases caused by asbestos dust: asbestosis (lung scarring), bronchial (lung) cancer and mesothelioma from inhaled fibers, and asbestos corns, formed when fibers lodge in finger skin. The review described a 1959 survey of asbestos textile workers. Those who worked in the industry before dust-control improvements in the 1930s had a 10-fold excess of lung cancer. It also said present evidence indicated that cigarette smokers exposed to asbestos dust had a lung cancer risk at least fifty times that of unexposed non-smokers. Mesothelioma was rarely detected under 20 years after first exposure; smoking seemed to play no part in it. Mesothelioma risk was described as probably highest with crocidolite, lowest with chrysotile, and with amosite probably in between. The author said information on risks by fiber type was far from complete. The author concluded that the 1969 Asbestos Regulations, if correctly applied, should greatly reduce future risks, and that proof depends on much better record keeping.

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 the health hazards of asbestos; no original data were collected
• Who was studied: No population was studied directly. The review drew on earlier surveys of asbestos workers, mostly asbestos textile workers, and on animal experiments.
• Exposure: Inhaled asbestos dust, including the commercial fiber types amosite, anthophyllite, chrysotile and crocidolite, in mining, textile and manufacturing work
• Main results:
  • The review described a 1959 survey. Asbestos textile workers who worked before the 1930s dust-control improvements had a 10-fold excess of lung cancer.
  • The review said improved dust control at a particular factory after 1933 had materially reduced the lung cancer risk.
  • The review stated that present evidence indicated cigarette smokers exposed to asbestos dust had a lung cancer risk at least fifty times greater than non-smokers not exposed to asbestos dust.
  • The interval between first asbestos exposure and detection of mesothelioma was described as rarely less than 20 years.
  • Cigarette smoking was said to seem to play no part in mesothelioma.
  • Asbestos corns were described as forming on the fingers when fibers lodge in the skin. Removing the fiber usually cures the corn, and no skin cancers relatable to asbestos had been reported.
  • Mesothelioma risk was described as probably highest with crocidolite and lowest with chrysotile, with amosite probably in between. No cases clearly related to anthophyllite alone had been reported.
  • Under the 1969 Asbestos Regulations, the dust standard for crocidolite was set at one-tenth of that for other types of asbestos.
  • Feeding massive doses of asbestos to animals had so far failed to produce mesotheliomas or other cancers.
  • For workers heavily exposed in the past to the more damaging types of asbestos dust, excess deaths from all causes were described as closely comparable to those of coal miners with the severer form of pneumoconiosis. This excess was less than that of male smokers of twenty cigarettes or more a day compared with non-smokers.
• The authors' conclusion: The author concluded that the recent increase in asbestos-related disease resulted from relatively heavy past exposures. The new Asbestos Regulations 1969, if correctly applied, should greatly reduce risks in the future. Proof that preventive measures work depends on much better record keeping.
• Limitations the authors state:
  • The author stated that the assessment of past risks from different fiber types and occupations rested on information that was far from complete.
  • Past records of dustiness were rarely available to relate to how often the diseases occurred.
  • The evidence for a dose-response relationship was described as less clear for mesothelioma, making its threshold limit value more difficult to assess.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Asbestos Corns, Lung Cancer, Crocidolite, Chrysotile, Amosite.

Browse return to medical research.