The silence: the asbestos industry and early occupational cancer research--a case study

Our plain-English summary of The silence: the asbestos industry and early occupational cancer research--a case study, by D.E. Lilienfeld (American Journal of Public Health, 1991).

The study

• Author: D.E. Lilienfeld
• Journal: American Journal of Public Health
• Published: 1991;81(6):791-800
• Type of article: Historical article
• Cited by: 54 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. 004100).

Abstract

To gain insight into corporate activities regarding the identification of occupational carcinogens earlier in this century, the actions of one industry, the asbestos industry, were reviewed. This industry, in concert with many of its insurers, systematically developed and then suppressed information on the carcinogenicity of asbestos. The development of warnings for those exposed to the asbestos was delayed. As a result, millions of workers were exposed to the carcinogen and hundreds of thousands died. These events are placed into the context of similar activities in other industries during this time.

In plain English

This article was a historical case study, not a medical study of patients. The author reviewed letters, memos, meeting minutes and reports from asbestos companies, insurers (notably Metropolitan Life) and the Saranac Laboratory. These documents became public through lawsuits. After background from the late 1800s, it focused on 1929 to 1979 in the United States, Canada and England. A 1936 research contract let the sponsoring companies decide whether results would be made public. An interim report on Saranac animal experiments noted lung tumors in 81.8 percent of asbestos-exposed animals. In a later draft, the cancer section was marked "out" before the 1951 publication; one research team member stated this was unrelated to sponsor pressure. A later Saranac animal study found more cancer at 14 months in exposed animals and was not published. The author also described an English lung cancer study the company at first refused permission to publish, a 1958 report printed without its sentence linking asbestosis to lung cancer, and delayed or removed warning labels. The author concluded that data were generated and then suppressed over half a century.

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: historical case study based on corporate and legal documents obtained through litigation
• Who was studied: asbestos companies and trade associations, insurers (especially Metropolitan Life), and researchers and physicians (including the Saranac Laboratory) in the United States, Canada and England. The main documentary period is about 1929 to 1979, with background on the industry's growth from the late 1800s.
• Exposure: occupational asbestos exposure in general, and what the industry knew and disclosed about asbestosis and then cancer; no fiber-specific doses were studied
• Main results:
  • The 1936 contract between asbestos companies and the Saranac Laboratory gave the funding companies control over whether and how results were made public
  • An interim report on Saranac Laboratory animal experiments noted that 81.8 percent of animals exposed to asbestos developed lung tumors; a sponsor (Keasbey and Mattison) wrote that the reference to cancer susceptibility should be omitted
  • In the January 31, 1949 draft of the Saranac report, the 'Neoplasm' section was marked 'out'; the revised report was published in 1951
  • One member of the investigative team stated that removing the cancer section was unrelated to sponsor pressure
  • In the QAMA-sponsored Saranac Laboratory animal study, asbestos-exposed animals had a higher cancer incidence than unexposed animals at 14 months; the study was not published
  • Turner and Newall at first refused permission to publish the Knox and Doll study of lung cancer in Rochdale asbestos workers; it was published in 1955 with Knox acknowledged anonymously
  • Johns-Manville's legal department proposed a caution label for asbestos fiber bags in 1952, but a warning label was not added for another 13 years
  • The Braun report on lung cancer in asbestos miners was published in 1958 in condensed form, without its concluding sentence that miners with asbestosis had a greater likelihood of lung cancer
  • 1965 Johns-Manville memos stated that on exported products, warnings on bags should be covered and those on crates sanded off
• The authors' conclusion: The author concluded that, over half a century, the asbestos industry and its associates planned and carried out concerted actions in which data were generated and then suppressed. The author questioned the effectiveness of the current occupational safety and health framework.
• Limitations the authors state:
  • The author noted there is no direct evidence that the early asbestosis reports alarmed the industry; this was inferred from later events
  • Some claims rest on personal communication and allegation, such as who paid for Lanza's trip to California
  • The author stated that a full discussion of the adequacy of the current occupational safety and health framework was beyond the scope of the paper

Topics

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

Related studies

• Occupational health research in India — H.N. Saiyed, R.R. Tiwari (2004)
• Sources in the history of occupational health: the Turner & Newall archive — G. Tweedale (2000)
• Job tasks, potential exposures, and health risks of laborers employed in the construction industry — G. Burkhart, P.A. Schulte, et al. (1993)
• Asbestos and cancer: an early warning to the British TUC — N.J. Wikeley (1992)
• Controversies at international organizations over asbestos industry influence — B.I. Castleman (2001)
• Medical research in the Rhondda valleys — H.F. Thomas (1999)

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