Determination of iron, chromium, cobalt, nickel, and scandium in asbestos by neutron activation analysis

Our plain-English summary of Determination of iron, chromium, cobalt, nickel, and scandium in asbestos by neutron activation analysis, by A. Holmes, A. Morgan, J. Sandalls (American Industrial Hygiene Association Journal, 1971).

The study

• Authors: A. Holmes, A. Morgan, J. Sandalls
• Journal: American Industrial Hygiene Association Journal
• Published: 1971;32(5):281-6
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy.

In plain English

This was a laboratory chemistry study of asbestos fibers. It did not study workers or illness. At the Atomic Energy Research Establishment, Harwell, the authors used neutron activation analysis to measure iron, chromium, cobalt, nickel and scandium. They tested the five UICC standard reference samples: South African amosite, Finnish anthophyllite, Rhodesian chrysotile A, Canadian chrysotile B and South African crocidolite. They also tested chrysotile from the Canadian mines blended to make chrysotile B, and crocidolite from two South African regions. Iron was 1.7% in chrysotile A and 2.6% in chrysotile B, but 28% in amosite and 27% in crocidolite. Chromium was 1390 ppm in chrysotile A and 16 ppm in crocidolite. Among the Canadian mines, Cassiar chrysotile had the most chromium and scandium, and Carey chrysotile the most cobalt and nickel. Milling did not significantly change the iron, chromium, cobalt or scandium content of the reference samples. The crocidolite samples from the two regions did not appear to differ significantly in the concentrations of the elements measured. The authors concluded that the reference samples appeared representative of their sources for trace metals.

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 analysis of asbestos samples by neutron activation analysis, carried out at the Atomic Energy Research Establishment, Harwell, United Kingdom
• Who was studied: Asbestos samples, not people. These were the five UICC standard reference samples of asbestos; the individual Canadian chrysotile samples, from eight mines, that were blended to make chrysotile B (two samples from six mines, one from each of the other two); and crocidolite samples from the North West Cape and Transvaal deposits in South Africa.
• Exposure: No human exposure was studied. The fibers analyzed were South African amosite, Finnish anthophyllite, Canadian chrysotile (chrysotile B, pooled from eight mines), Rhodesian chrysotile from a single mine (chrysotile A) and South African crocidolite.
• Main results:
  • In repeat analyses of chrysotile B (mean and standard deviation), iron was 2.6 plus or minus 0.1%, chromium 490 plus or minus 10 ppm, cobalt 46 plus or minus 1 ppm, nickel 990 plus or minus 210 ppm and scandium 5.5 plus or minus 0.1 ppm.
  • UICC chrysotile A contained 1.7% iron, 1390 ppm chromium, 55 ppm cobalt, 1250 ppm nickel and 6 ppm scandium. Chrysotile B contained 2.6% iron, 490 ppm chromium, 46 ppm cobalt, 990 ppm nickel and 5 ppm scandium. Anthophyllite contained 4.4% iron, 870 ppm chromium, 50 ppm cobalt, 1360 ppm nickel and 5 ppm scandium.
  • UICC amosite contained 28% iron, 35 ppm chromium, 7 ppm cobalt, less than 100 ppm nickel and 5 ppm scandium. UICC crocidolite contained 27% iron, 16 ppm chromium, 2 ppm cobalt, less than 100 ppm nickel and 0.5 ppm scandium.
  • Milling did not significantly alter the iron, chromium, cobalt or scandium content of the UICC samples compared with the coarse asbestos they were made from.
  • Among the Canadian chrysotile samples, those from the Cassiar mine had the highest chromium and scandium, and those from the Carey mine had the highest cobalt and nickel.
  • Canadian chrysotile samples taken from different bags from the same mine had similar composition.
  • The crocidolite samples from the North West Cape and Transvaal deposits did not appear to differ significantly in the concentrations of the elements measured.
  • Nickel was below the limit of detection (less than 100 ppm) in all the South African crocidolite samples.
  • Chromium in some Canadian chrysotile samples was fairly insoluble. Refluxing with hydrochloric acid may dissolve less than half of it.
• The authors' conclusion: The authors compared their values with ranges reported by Cralley et al. They concluded that this suggests the UICC standard reference samples are representative of their respective sources as far as trace metals are concerned.
• Limitations the authors state:
  • In the precision tests, nickel could not be measured accurately, because the signal used to measure it is swamped by a much larger cobalt signal. The authors state that the nickel values for the reference samples were obtained with a modified method expected to be more accurate.
  • The milling comparison could not assess whether nickel content was changed.
  • The trace metals measured may come from contaminating minerals such as magnetite, brucite or chromite rather than from the fiber itself.

Mines named here

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

• Cassiar mine, British Columbia
• Malips Drift (McBean's) mine, near Malips River, Transvaal

All asbestos mines

Related studies

• Chromium and nickel in Pteridium aquilinum from environments with various levels of these metals — K. Kubicka, A. Samecka-Cymerman, et al. (2015)
• Chromium and nickel — G. Kazantzis (1972)
• Some observations on the distribution of trace metals in chrysotile asbestos — A. Morgan, A.E. Lally, et al. (1973)
• A redox-silent analogue of tocotrienol inhibits cobalt(II) chloride-induced VEGF expression via Yes signaling in mesothelioma cells — A. Sato, N. Virgona, et al. (2014)
• Inter-rater agreement for a retrospective exposure assessment of asbestos, chromium, nickel and welding fumes in a study of lung cancer and ionizing radiation — E.A. Seel, D.D. Zaebst, et al. (2007)
• Free radical activity of industrial fibers: role of iron in oxidative stress and activation of transcription factors — P.S. Gilmour, D.M. Brown, et al. (1997)

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