Leahing of constituents of chrysotile asbestos in vivo

Our plain-English summary of Leahing of constituents of chrysotile asbestos in vivo, by A. Holmes, A. Morgan (Nature, 1967).

The study

• Authors: A. Holmes, A. Morgan
• Journal: Nature
• Published: 1967;215(5099):441-2
• Cited by: 24 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This 1967 letter described an experiment in two rats. The authors tested whether radioactivity induced in Rhodesian chrysotile by neutron irradiation could trace the fibres' movement in the body; the main radioactive substances produced were scandium-46, chromium-51, iron-59 and cobalt-60. Each rat received about 3 mg of asbestos injected into the pleural cavity, the space around the lungs. One was killed after 8 days and the other after 50 days. Urine contained only radioactive chromium and cobalt. After 50 days, 19 per cent of the chromium-51 and 57 per cent of the cobalt-60 had been excreted this way; the authors said both metals were leached quite rapidly. Iron appeared to be leached to a much smaller extent, and no conclusion was possible for scandium. In both rats about 90 per cent of remaining radioactivity was in the pleural cavity and lungs, some linked to visible plaques on the diaphragm and pleura. The authors concluded that fibres move out of the pleural cavity comparatively slowly. Small amounts outside the chest suggested some movement does occur, but the authors said proof needed more evidence.

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: a feasibility study of tracing neutron-irradiated asbestos fibres in rats
• Who was studied: Two 3-month-old rats. One was killed after 8 days and the other after 50 days. The authors were at the Atomic Energy Research Establishment, Harwell.
• Exposure: Rhodesian chrysotile made radioactive by thermal neutron irradiation. It was suspended in saline and injected into the pleural cavity, about 3 mg of asbestos per rat. The main radioactive constituents were scandium-46, chromium-51, iron-59 and cobalt-60.
• Main results:
  • Urine samples contained only chromium-51 and cobalt-60.
  • After 50 days, 19 per cent of the chromium-51 and 57 per cent of the cobalt-60 had been excreted in urine.
  • The authors stated this showed that chromium and cobalt are both leached quite rapidly from chrysotile in the body.
  • All four radionuclides were detected in faeces, in comparatively small amounts.
  • Relatively high iron-59 levels in blood and liver indicated that iron is also leached, but much less than chromium or cobalt.
  • In both rats, about 90 per cent of each radionuclide remaining at death was in the pleural cavity and lungs.
  • Some of the activity was associated with visible plaques on the diaphragm and pleura.
• The authors' conclusion: The authors concluded that movement of fibres out of the pleural cavity into other organs is a comparatively slow process. They said the small amounts found outside the chest suggested that some movement occurs.
• Limitations the authors state:
  • No conclusions could be drawn about leaching of scandium.
  • Additional evidence, possibly from autoradiographic studies, is needed to prove conclusively that fibres move outside the chest.

Topics

Medical terms in this study, explained in our Lexicon: Chrysotile.

Related studies

• Change of heme oxygenase-1 expression in lung injury induced by chrysotile asbestos in vivo and in vitro — H. Nagatomo, Y. Morimoto, et al. (2007)
• Solubility of rockwool fibres in vivo and the formation of pseudo-asbestos bodies — A. Morgan, A. Holmes (1984)
• The effects of chrysotile and crocidolite asbestos on the lower respiratory tract: analysis of bronchoalveolar lavage constituents — E. Kagan, Y. Oghiso, et al. (1983)
• The effects of polyvinyl pyridine-N-oxide (P204) on the cytopathogenic action of chrysotile asbestos in vivo and in vitro — J.M. Davis (1972)
• Chrysotile asbestos causes AEC apoptosis via the caspase activation in vitro and in vivo — T. Kido, Y. Morimoto, et al. (2008)
• Some observations on the distribution of trace metals in chrysotile asbestos — A. Morgan, A.E. Lally, et al. (1973)

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