Chemical studies of asbestos

Our plain-English summary of Chemical studies of asbestos, by J.S. Harington (Annals of the New York Academy of Sciences, 1965).

The study

• Author: J.S. Harington
• Journal: Annals of the New York Academy of Sciences
• Published: 1965;132(1):31-47
• Cited by: 41 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy.

Abstract

Further chemical studies of the three main types of asbestos, crocidolite, amosite and chrysotile, have been made.

The origin of the primary oils associated with crocidolite and amosite has been discussed. By suitable methods 0.32 per cent of extractable material can be removed from crocidolite and 0.28 per cent from amosite. A sample of commercial amosite known to be carcinogenic yielded 0.76 per cent of extractable material. Chemical investigations have been made of the oils from crocidolite and amosite by various techniques. Low levels of polycyclic aromatic hydrocarbons were detected.

In addition to the primary oils, asbestos may contain secondary oils derived from contamination or from the intentional application of oil during processing in industry. Up to 80 per cent of the jute oil in the jute bags used for storing asbestos may be absorbed by the asbestos fiber. This could explain why chrysotile, which apparently has no primary oils, may contain, after milling and other industrial treatment, yields of from 0.1 per cent to 0.4 per cent. Insulation materials also contain significant amounts of extractable material.

Finally, studies have been made to assess, wherever possible, the part which metals and metal complexes may play in the carcinogenic action.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This 1965 paper reported laboratory chemical analyses of crocidolite, amosite and chrysotile asbestos. It did not study people. Solvent extraction removed 0.32 per cent extractable material from crocidolite and 0.28 per cent from amosite. No natural organic matter was found in virgin chrysotile. A commercial amosite sample described as known to be carcinogenic yielded 0.76 per cent. Low levels of polycyclic aromatic hydrocarbons were detected. The author compared an unused jute bag with one that had held crocidolite for an unknown period, and reported that 74.5 per cent of the oil may be removed by crocidolite. In a six-month test, a small jute pocket holding crocidolite lost 75 per cent of its oil. The author said such isolated observations could not be regarded as conclusive. A single chrysotile sample contained nickel (0.5 per cent) and chromium (0.1 per cent). Serum removed small amounts of iron, which the author considered probably too small to have a significant biological effect. The author wrote that the radioactivity values suggested no more than a very minor role in cancer induction by asbestos, and said the significance of the asbestos oils was at present unknown.

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: laboratory chemical analysis of asbestos samples: organic matter (oils), metals, elution of metals by serum, and radioactivity; no human or animal subjects were studied in this paper
• Who was studied: samples of crocidolite, amosite and chrysotile asbestos, including crocidolite and amosite cobs specially taken from mines, a commercial amosite sample supplied by Selikoff, jute bags used for storing asbestos, and five insulation material samples
• Exposure: the three main types of asbestos (crocidolite, amosite and chrysotile), their natural (primary) and contaminating (secondary) oils, metal content, and radioactivity
• Main results:
  • Successive solvent extraction removed 0.32 per cent extractable material from crocidolite and 0.28 per cent from amosite
  • No natural (primary) organic matter was found in virgin chrysotile
  • A commercial amosite sample described as known to be carcinogenic yielded 0.76 per cent extractable material
  • Low levels of polycyclic aromatic hydrocarbons were detected in the oils from crocidolite and amosite
  • The author compared a clean unused jute bag with a similar bag that had held crocidolite in a mill for an unknown period. From this comparison, the author reported that 74.5 per cent of oil may be removed from jute bags by crocidolite
  • In a six-month laboratory test, a small jute pocket containing crocidolite lost 75 per cent of its oil
  • Insulation materials contained extractable material
  • In single samples analysed spectrochemically, the chrysotile sample contained nickel (0.5 per cent) and chromium (0.1 per cent)
  • Serum removed about 5 per cent of acid-removable iron from crocidolite and chrysotile and about 1 per cent from amosite. The author considered these amounts probably too small to exert a significant biological effect
  • Radioactivity of the asbestos samples was low, similar to chalk
• The authors' conclusion: The author wrote that the radioactivity values suggest radioactivity plays no more than a very minor role in the induction of cancer by asbestos. The author also stated that the significance of the asbestos oils and of the extractable material in insulation is at present unknown
• Limitations the authors state:
  • The jute-bag results were isolated observations that could not be regarded as conclusive
  • It was not yet possible to distinguish primary (natural) from secondary (contaminating) oils on crocidolite and amosite
  • Low total recoveries from column separation of the oils suggested either loss of low-boiling components or retention of very polar material

Mines named here

Asbestos mines this study is about. Each mine's page says who ran it, when it worked, and what it produced.

• Johnson's Co. mine, Thetford Mines, Quebec

All asbestos mines

Topics

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

Related studies

• Studies of carcinogenesis of asbestos fibers and their natural oils — J.S. Harington, F.J. Roe (1965)
• Mineral particles of varying composition induce differential chemokine release from epithelial lung cells: importance of physico-chemical characteristics — J. Ovrevik, T. Myran, et al. (2005)
• Asbestos minerals in modern technology — S. Speil, J.P. Leineweber (1969)
• Mesotheliomas in rats following inoculation with acid-leached chrysotile asbestos and other mineral fibres — G. Monchaux, J. Bignon, et al. (1981)
• The detection and localization of mineral fibers in tissue — C. Berkley, J. Churg, et al. (1965)
• Characterization of talc and associated minerals — D.H. Hamer, F.R. Rolle, et al. (1976)

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