Pulmonary Fibrosis, Carcinoma, and Ferruginous Body Counts in Amosite Asbestos Workers: A Study of Six Cases

Our plain-English summary of Pulmonary Fibrosis, Carcinoma, and Ferruginous Body Counts in Amosite Asbestos Workers: A Study of Six Cases, by Victor L. Roggli, S. Donald Greenberg, Leonard H. Seitzman, et al (1980).

The study

• Authors: Victor L. Roggli, S. Donald Greenberg, Leonard H. Seitzman, Malcolm H. McGavran, George A. Hurst, Charles G. Spivey, Kenwyn G. Nelson, LeRoy R. Hieger
• Published: Am J Clin Pathol 73: 496-503 (1980)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This report described six former workers in the Tyler Asbestos Workers Program, from a plant in Tyler, Texas, that made pipe insulation from amosite asbestos. Five had died and been autopsied, and one had part of a lung removed for cancer. All were cigarette smokers, and five had been exposed for three months or less. Four had lung cancer and one had rectal carcinoma. The authors counted ferruginous (asbestos) bodies in lung tissue and graded fibrosis on tissue sections. Controls were lung samples from 52 consecutive autopsies of adults with no known occupational asbestos exposure. Per gram of wet lung tissue, the workers' upper-lobe counts averaged 8,520 and lower-lobe counts 5,020, while the controls averaged four. Moderate to severe fibrosis went with mean counts above 10,000 per gram of wet lung tissue, and no or mild fibrosis with mean counts below 700. Mild to moderate fibrosis could be seen on tissue sections before chest X-rays showed changes. Fibers from one worker were identified as amosite. The authors concluded that workers with brief exposure may still be at risk of cancers. They noted that they counted only coated fibers.

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: Case series of six workers (five autopsies, one lobectomy), compared with a control group of autopsy lung tissue
• Who was studied: Six former workers (all men, mean age 63, all cigarette smokers) from the Tyler Asbestos Workers Program. The program is a continuing study of former amosite asbestos workers from a plant in Tyler, Texas, that operated from 1954 to 1972. Controls were 52 adults from consecutive autopsies at The Methodist Hospital in Houston, Texas (mean age 58.5, range 20 to 89), with no occupations associated with known asbestos exposure.
• Exposure: Amosite asbestos imported from South Africa, used to fabricate pipe insulation at the Tyler plant
• Main results:
  • Five of the six workers were exposed for three months or less. One (Patient 1) was employed at the Tyler plant for seven years.
  • Four of the six workers had lung cancer and one had rectal carcinoma
  • Among the six workers, the mean ferruginous body count per gram (wet weight) was 8,520 in upper-lobe tissue (range 13 to 34,200) and 5,020 in lower-lobe tissue (range 14 to 27,500)
  • The control group had a mean of four ferruginous bodies per gram wet weight. The six workers had a combined upper and lower lobe mean of 6,770 per gram wet weight.
  • In the workers, moderate (2+) and severe (3+) fibrosis occurred with mean counts above 10,000 ferruginous bodies per gram of lung tissue (wet weight). These were Patients 1, 4 and 5, who died 20 to 21 years after first employment, and all three had lung cancer.
  • In the workers, absent (0) or mild (1+) fibrosis occurred with mean counts below 700 ferruginous bodies per gram of lung tissue (wet weight) (Patients 2, 3 and 6)
  • Two of the six workers (Patients 3 and 6) had lung concentrations of ferruginous bodies below 100 per gram
  • Mild to moderate fibrosis could be identified on tissue sections before interstitial changes were detectable on chest X-rays
  • Iron-stained tissue sections gave a rough impression of ferruginous body numbers but were much less sensitive than tissue digestion
  • Electron diffraction and x-ray analysis of ferruginous body cores from Patient 1 identified the core fibers as amosite asbestos
• The authors' conclusion: The authors concluded that their findings confirm the latency period from asbestos exposure to cancer. They also concluded that workers with relatively brief exposure (around three months) may still be at risk for cancers.
• Limitations the authors state:
  • The authors examined only coated asbestos fibers (ferruginous bodies), not uncoated or submicroscopic fibers

Topics

Medical terms in this study, explained in our Lexicon: Pulmonary Fibrosis, Carcinoma, Ferruginous body, Amosite, Pipe Covering, Lung Cancer, Fibrosis, Asbestos Exposure.

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