Mortality experience of insulation workers in the United States and Canada, 1943--1976

Our plain-English summary of Mortality experience of insulation workers in the United States and Canada, 1943--1976, by I.J. Selikoff, E.C. Hammond, H. Seidman (Annals of the New York Academy of Sciences, 1979).

The study

• Authors: I.J. Selikoff, E.C. Hammond, H. Seidman
• Journal: Annals of the New York Academy of Sciences
• Published: 1979;330:91-116
• Cited by: 349 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001055).

Summary of the article

This study examined mortality among asbestos insulation workers in two cohorts. One comprised the 632 men in two New York-New Jersey union locals on January 1, 1943, followed to December 31, 1976, plus 833 men who joined these locals in 1943-1962. The other comprised all 17,800 members of the insulation workers' union in the United States and Canada on January 1, 1967, followed to December 31, 1976. Observed deaths were compared with those expected from U.S. white male age-specific death rates. Causes of death were assigned from death certificates and also from review of the best available evidence (autopsy, surgical, clinical). By 1976, 478 of the 632 men had died, including 93 of lung cancer (13.3 expected), 38 of mesothelioma and 41 of asbestosis. Among the 17,800 men, 2271 died (1658.9 expected), including 486 of lung cancer (105.6 expected), 175 of mesothelioma and 168 of asbestosis. Little increase in cancer or asbestosis deaths was seen less than 15-19 years from onset of exposure. Death certificates listed 49 pancreatic cancer deaths, but review confirmed 23. They listed 78 asbestosis deaths, against 168 after review. The authors concluded that insulation workers had an extraordinary increased risk of death from cancer and asbestosis, and that studies should observe workers 30-40 or more years from onset. They also concluded that adding amosite to chrysotile did not demonstrably alter the resulting diseases.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This study tracked deaths among members of the asbestos insulation workers' union. One group was 632 men in two New York-New Jersey locals on January 1, 1943, followed through 1976. A larger group was all 17,800 union members in the United States and Canada on January 1, 1967, followed through 1976. Observed deaths were compared with numbers expected from U.S. white male death rates. Among the 632 men, 76% had died by the end of 1976. There were 93 lung cancer deaths against 13.3 expected, 38 mesothelioma deaths (11 pleural, 27 peritoneal) and 41 asbestosis deaths. Among the 17,800 men there were 2271 deaths against 1658.9 expected. These included 486 lung cancer deaths (between four and five times the number expected), 175 mesothelioma deaths (63 pleural, 112 peritoneal) and 168 asbestosis deaths, as classified after review of medical records. Most of the excess appeared 20 or more years after first exposure. Death certificates alone listed 49 pancreatic cancer deaths, against 23 after review, and only 78 asbestosis deaths. The authors concluded that these workers had an extraordinary increased risk of death from cancer and asbestosis associated with their employment.

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: Prospective cohort mortality study of union members, comparing observed deaths with expected deaths
• Who was studied: 17,800 men on the rolls of the insulation workers' union (International Association of Heat and Frost Insulators and Asbestos Workers) in the United States and Canada on January 1, 1967, followed to December 31, 1976. Also studied: 632 men in two New York-New Jersey locals on January 1, 1943, followed through 1976, and 833 men who joined those locals in 1943 to 1962 with no prior asbestos employment.
• Exposure: Asbestos insulation work (magnesia block, asbestos cement, asbestos paper products). Chrysotile alone was used until about the early 1940s. Amosite was used in small amounts from the mid-1930s and more widely during and after World War II. The authors estimated past dust levels of 4 to 12 fibers/ml as time-weighted averages.
• Main results:
  • Among the 632 New York-New Jersey men, 76% had died by the end of 1976.
  • New York-New Jersey cohort (632 men), 1943 to 1976: 93 lung cancer deaths observed versus 13.3 expected.
  • New York-New Jersey cohort (632 men): 38 mesothelioma deaths, 11 pleural and 27 peritoneal.
  • New York-New Jersey cohort (632 men): 43 gastrointestinal cancer deaths versus 15.1 expected, and 41 asbestosis deaths.
  • 833 men first employed 1943 to 1962, at 20 to 34 years from onset (3281 man-years): about three times as many cancer deaths as expected, mainly lung cancer.
  • 17,800 U.S. and Canadian members, 1967 to 1976: 2271 deaths versus 1658.9 expected from U.S. white male death rates.
  • 17,800 members: 486 lung cancer deaths (bronchogenic carcinoma), between 4 and 5 times the number expected.
  • 17,800 members: 175 mesothelioma deaths, 63 pleural and 112 peritoneal.
  • 17,800 members: after review of records, 168 deaths were assigned to asbestosis and 44 to other noninfectious pulmonary diseases.
  • 17,800 members: 11 larynx cancer deaths, 21 buccal cavity and oro-pharynx cancer deaths and 19 kidney cancer deaths, each about twice the number expected.
  • 17,800 members, deaths less than 20 years from onset of exposure (12,683 men): 83 cancer deaths observed versus 42.6 expected.
  • 17,800 members, 20 or more years from onset (12,051 men): 1946 deaths versus 1376.0 expected, including 160 asbestosis deaths and 912 cancer deaths.
  • 17,800 members: mesothelioma death rates reached 2.78 per thousand person-years for pleural mesothelioma at 35 to 39 years from onset, and 5.47 per thousand person-years for peritoneal mesothelioma at 45 or more years.
  • 17,800 members: death certificates listed 49 pancreatic cancer deaths, but only 23 were pancreatic cancer after review of all available material.
  • 17,800 members: death certificates listed 78 asbestosis deaths, compared with 168 after review.
  • Comparing New York-New Jersey men first exposed before 1943 (chrysotile only) with those first exposed from 1943 on (chrysotile and amosite), the authors found that amosite did not shorten the latency period for asbestos-associated disease.
• The authors' conclusion: The authors concluded that asbestos insulation workers in the United States and Canada had an extraordinary increased risk of death from cancer and asbestosis associated with their employment. They also concluded that analyses should be done by time since first exposure, and that reviewing all available medical information gives more accurate causes of death than death certificates alone.
• Limitations the authors state:
  • There is no perfect comparison group that accounts for age distribution, ethnic origin, smoking habits and other factors.
  • Causes of death recorded on death certificates may be wrong.
  • Deaths in the general population, from which expected numbers were calculated, were not verified, so errors in the expected rates cannot be measured.
  • Expected numbers could not be calculated for mesothelioma.
  • Detailed medical information was not equally available for all causes of death.
  • Knowing that a person was exposed to asbestos may have raised diagnostic suspicion and could explain some overdiagnosis.
  • The authors had no information on risk among insulation workers who began work after 1963.

Topics

Medical terms in this study, explained in our Lexicon: Insulator, Death Certificate, Autopsy, Lung Cancer, Mesothelioma, Amosite, Chrysotile.

Related studies

• Mortality of brain tumors among asbestos insulation workers in the United States and Canada — H. Seidman, I.J. Selikoff, et al. (1982)
• Asbestos-associated deaths among insulation workers in the United States and Canada, 1967-1987 — I.J. Selikoff, H. Seidman (1991)
• The occurrence of asbestosis among insulation workers in the United States — I.J. Selikoff, J. Churg, et al. (1965)
• Neoplasia among insulation workers in the United States with special reference to intra-abdominal neoplasia — E.C. Hammond, I.J. Selikoff, et al. (1965)
• Mortality among asbestos products workers in the United States — P.E. Enterline (1965)
• Decline in death rates among asbestos insulation workers 1967-1986 associated with diminution of work exposure to asbestos — H. Seidman, I.J. Selikoff (1990)

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