Asbestos and smoking

Our plain-English summary of Asbestos and smoking, by I.J. Selikoff, E.C. Hammond (JAMA, 1979).

The study

• Authors: I.J. Selikoff, E.C. Hammond
• Journal: JAMA
• Published: 1979;242(5):458-9
• Type of article: Editorial
• Cited by: 73 articles, as counted by NIH iCite
• Read it: PubMed
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001053).

In plain English

This short JAMA editorial described 12,051 asbestos insulation workers followed from January 1, 1967, through December 31, 1976. All were at least 20 years past starting their work. Comparison men came from an American Cancer Society study and had similar backgrounds and smoking habits. Age-standardized lung cancer death rates per 100,000 man-years were 38.4 for asbestos workers who did not smoke, 122.6 for smokers who had not worked with asbestos, and 601.6 for men with both exposures. For men who neither worked with asbestos nor smoked, the scan prints 113. That cannot be right because the article says asbestos alone raises risk, and the correct figure cannot be confirmed. Five asbestos workers who never smoked died of asbestosis. Asbestosis death rates for men who smoked "pack or more" a day were 2.8 times those for men who never smoked regularly; the amount before "pack" is unreadable in the scan. Over ten years, lung cancer death rates for 2,201 men who had quit by 1967 were approximately one third of those of workmates still smoking. The authors concluded that asbestos-exposed workers should be advised never to smoke or to stop. They noted that mesothelioma would not be affected.

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: Editorial summarizing results of a follow-up (cohort) study of asbestos insulation workers, compared with men from the American Cancer Society's prospective cancer prevention study
• Who was studied: 12,051 asbestos insulation workers followed from Jan 1, 1967 to Dec 31, 1976, all at least 20 years from the start of their work. The comparison men came from the American Cancer Society study. They were white, had similar socioeconomic backgrounds, were exposed at work to dust, fumes, chemicals and gases, did not work as farmers, and had the same distribution of smoking habits. The size of the comparison group is not legible.
• Exposure: Asbestos insulation work (fiber types not specified) and cigarette smoking
• Main results:
  • Age-standardized lung cancer death rate per 100,000 man-years: 38.4 for men who worked with asbestos but did not smoke
  • Age-standardized lung cancer death rate: 122.6 for cigarette smokers who had not worked with asbestos
  • Age-standardized lung cancer death rate: 601.6 for men with both exposures, cigarettes and asbestos
  • Age-standardized lung cancer death rate for men who neither worked with asbestos nor smoked prints as 113, which conflicts with the article's statement that asbestos by itself increases lung cancer risk. The correct value cannot be confirmed from this text.
  • Among asbestos workers, the authors stated that one in every five deaths is due to lung cancer
  • Five men who never smoked cigarettes died of asbestosis. Asbestosis mortality for men who smoked "pack or more" a day was 2.8 times as high as for men who never smoked regularly. The amount before "pack" is unreadable in the scan.
  • In 1967, 2,201 men reported they had stopped smoking and 4,472 were still smoking. Over the next ten years, lung cancer mortality among those who stopped was approximately one third of that among workmates who continued to smoke.
• The authors' conclusion: The authors concluded that workers exposed to asbestos should be advised never to smoke or to stop as soon as possible. They stated that periodic medical surveillance and treatment of lung infections would further reduce risks, but that mesothelioma would not be affected.
• Limitations the authors state:
  • The authors noted that the comparison group was not a perfect control group, though they considered it as similar as they could find

Topics

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

Related studies

• Occupational lung cancer and smoking: a review in the light of current theories of carcinogenesis — A.C. Chovil (1979)
• Combined effect of asbestos exposure and smoking on mortality from lung cancer in factory workers — G. Berry, M.L. Newhouse, et al. (1972)
• Interaction of asbestos, age, and cigarette smoking in producing radiographic evidence of diffuse pulmonary fibrosis — K.H. Kilburn, R. Lilis, et al. (1986)
• Asbestos exposure, smoking, and neoplasia — I.J. Selikoff, E.C. Hammond, et al. (1968)
• Asbestosis: interstitial pulmonary fibrosis and pleural fibrosis in a cohort of asbestos insulation workers: influence of cigarette smoking — R. Lilis, I.J. Selikoff, et al. (1986)
• Radiographic abnormalities in asbestos insulators: effects of duration from onset of exposure and smoking. Relationships of dyspnea with parenchymal and pleural fibrosis — R. Lilis, A. Miller, et al. (1991)

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