Asbestos-induced tumors in White Leghorn fowls

Our plain-English summary of Asbestos-induced tumors in White Leghorn fowls, by P.R. Peacock, A. Peacock (Annals of the New York Academy of Sciences, 1965).

The study

• Authors: P.R. Peacock, A. Peacock
• Journal: Annals of the New York Academy of Sciences
• Published: 1965;132(1):501-6
• Cited by: 12 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy.

Summary of the article

The authors, at the Cancer Research Department of the Royal Beatson Memorial Hospital in Glasgow, studied how the air-sac and lung tissues of line-bred White Leghorn fowls react to asbestos, and whether tumors develop. Finely ground fibers suspended in tributyrin were injected into the axillary air sac. The fibers spread over the air-sac mesothelium and reached the pulmonary alveoli. Macrophages engulfed them and carried them to subepithelial lymphoid follicles. In a first experiment, six birds aged 2 to 6 years received 0.5 ml of "asbestos" of unknown origin. The six-year-old bird died a year later with a massive tumor of the right lung that had invaded neighbouring organs. In further experiments, 12 three-month-old pullets received 1 ml of amosite and 12 received 1 ml of crocidolite. In the amosite group, one bird killed at 42 months had a pleomorphic tumor involving the axillary air sac, pectoral muscles and left lung; it was grafted successfully into one of three pullets. In the crocidolite group, one bird killed at 40 months had a tumor classified as reticulosarcoma, possibly of mesothelial origin. Another bird had a granulomatous, non-neoplastic mass containing abundant fibers, and asbestos bodies were found in its lung. No such tumors had been seen in some hundreds of control birds over 36 years. The authors considered that, although the numbers were small, the findings seemed likely to have some significance.

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

In this animal experiment in Glasgow, the authors injected asbestos fibers suspended in tributyrin into an air sac just below the shoulder of line-bred White Leghorn fowls, a route reaching the lungs. In a first experiment, six birds aged 2 to 6 years received "asbestos" of unknown origin; a six-year-old bird died a year later with a massive tumor that involved the right lung and had invaded nearby organs. Later, 12 three-month-old pullets received amosite and 12 received crocidolite. One amosite-treated bird, killed at 42 months, had a tumor involving the air sac, chest muscles and left lung. One crocidolite-treated bird, killed at 40 months, had a tumor classified as a reticulosarcoma that the authors said may have been of mesothelial origin. A second crocidolite-treated bird had a mass that proved granulomatous, with abundant asbestos fibers and no cancerous tissue found. The authors reported seeing no such tumors in some hundreds of control birds over 36 years, and concluded that, although the numbers were small, the findings seemed to have some significance.

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: Animal experiment (injection of asbestos suspensions into the air sacs of fowls)
• Who was studied: Line-bred White Leghorn fowls at the Cancer Research Department, Royal Beatson Memorial Hospital, Glasgow, Scotland. The first experiment used six healthy birds aged 2 to 6 years. Later experiments used 12 three-month-old pullets given amosite and 12 three-month-old pullets given crocidolite. Dates of the experiments are not given.
• Exposure: First experiment: 0.5 ml of "asbestos" of unknown origin suspended in tributyrin, injected into the right axillary air sac. Later experiments: 1 ml of amosite (Penge PRS 4) or 1 ml of crocidolite (Westerberg RS 2,3,4) suspended in tributyrin, injected into the left axillary air sac. Finely ground fibers in this suspension reached the lung alveoli.
• Main results:
  • First experiment (six birds, asbestos of unknown origin): the six-year-old bird, No. 4581, died a year after injection with a massive tumor involving the right lung and extending around the carina, oesophagus, proventriculus and ovary, all of which were invaded. The article does not state where the tumor originated.
  • Amosite group (12 pullets): one bird was still alive after four years and one was lost after three years. Of the ten that died or were killed, one, No. 5822, killed after 42 months, had a large palpable tumor in the left axilla involving the axillary air sac, the pectoral muscles and the left lung.
  • Amosite group, bird No. 5822: no asbestos fibers could be recognized in the tumor, and the authors thought the cells were neoplastic (cancerous).
  • Amosite group, bird No. 5822: the tumor was successfully grafted into one of three young pullets.
  • Crocidolite group (12 pullets): 6 birds were alive after 48 months. Of the 6 that died or were killed, one, No. 5814, killed 40 months after the first injection, had a palpable tumor in the left axilla.
  • Crocidolite group, bird No. 5814: the tumor was classified as a reticulosarcoma, but the authors stated it may have been of mesothelial origin.
  • Crocidolite group, bird No. 5814: the tumor was grafted into six young pullets and grew in one.
  • Crocidolite group, bird No. 5811: a large mass in the left axilla, found 44 months after the first injection, proved to be granulomatous. No neoplastic tissue was identified, but there was abundant evidence of asbestos fibers.
  • In describing the granulomatous mass, the authors reported that many fibers appeared unchanged after almost four years, and that many asbestos bodies, similar to those found in asbestos workers, were identified in the lung.
  • The authors reported observing no such tumors in some hundreds of control birds, mostly breeding stock, over 36 years.
• The authors' conclusion: The authors concluded that, although the numbers were small, it seemed reasonable to think the tumors had some significance. They also concluded that the air-sac injection technique had proved satisfactory for studying how fowl tissues react to asbestos.
• Limitations the authors state:
  • The numbers of birds were small.
  • The study was incomplete at the time of writing: further tumors might develop in the seven surviving birds.
  • The suspensions could be injected into connective tissue instead of the air sac, as clearly happened in bird No. 5811.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelium, Alveoli, Macrophage, Amosite, Crocidolite, Pleomorphic, Asbestos Bodies.

Related studies

• Tests for effect of asbestos on benzo[a]pyrene carcinogenesis in the respiratory tract — L. Miller, W.E. Smith, et al. (1965)
• Tests for carcinogenicity of asbestos — W.E. Smith, L. Miller, et al. (1965)
• Morphological transformation of Syrian hamster embryo cells induced by mineral fibres and the alleged enhancement of benzo[a]pyrene — S.O. Mikalsen, E. Rivedal, et al. (1988)
• Evaluation of the tumorigenic potential of vermiculite by intrapleural injection in rats — B. Hunter, C. Thomson (1973)
• Experimentally induced mesothelioma in white rats in response to intraperitoneal administration of amorphous crocidolite asbestos: preliminary report — K. Kolev (1982)
• Pathogenesis of experimentally induced asbestos mesothelioma in rats — L.A. Vasilieva, L.N. Pylev, et al. (1998)

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