Metallic elements in crude and milled chrysotile asbestos from Quebec

Our plain-English summary of Metallic elements in crude and milled chrysotile asbestos from Quebec, by C. Barbeau, M. Dupuis, J.C. Roy (Environmental Research, 1985).

The study

• Authors: C. Barbeau, M. Dupuis, J.C. Roy
• Journal: Environmental Research
• Published: 1985;38(2):275-82
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Crude and milled fibers from different asbestos mines in Quebec have been analyzed for their metallic content. Crude fibers present a few metal concentrations that are characteristic for each mine. Manganese and iron can be used as discriminators, zinc and cobalt are constantly present in minute quantities, and calcium is virtually absent from crude fibers. Milled fibers are enriched in metals by factors ranging from 1.3 to greater than 15. Chromium and nickel concentrations are many times higher than in crude fibers and iron content is increased by more than 100%. Total metal content in milled fibers is mainly due to nonchrysotile material.

In plain English

This laboratory study measured metals in chrysotile asbestos from Quebec mines. The authors took crude fiber bundles from three sites in different veins at each of three mines (Jeffrey, Bell and Carey Canadian), plus host rock. They compared these with bagged commercial milled fibers (grade 3, or grade 4 for Carey). Samples were digested in acid; the residue was weighed as silica and the dissolved metals were measured by atomic absorption. In crude fibers, iron, manganese and nickel were almost constant within a mine but differed markedly between mines. Manganese was the only element that distinguished all five mines. Cobalt and zinc were present at very low levels, and calcium was not detected in crude fibers. Milled fibers showed a general increase in all metals, by factors from 1.3 to more than 15. Chromium and nickel were many times higher than in crude fibers; iron rose by more than 100%. The authors concluded that most metal in milled fibers comes from non-chrysotile material, which they suggested could behave very differently biologically. The study tested mineral samples, not people.

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 comparing crude and milled chrysotile asbestos fibers from Quebec mines, mainly by acid digestion and atomic absorption
• Who was studied: Mineral samples, not people. Crude chrysotile fibers came from three sites in different veins at each of three Quebec mines: Jeffrey mine (Asbestos), Bell mine (Thetford Mines) and Carey Canadian mine (East Broughton). Host rock samples were also taken. Milled fibers came from these mines and from Lake Asbestos and National mines. At least four samples were analyzed per site.
• Exposure: Chrysotile asbestos, crude fibers versus commercial milled fibers (grade 3; grade 4 for Carey Canadian mine), analyzed for metals including iron, manganese, nickel, cobalt, zinc, copper, chromium, aluminum, sodium, potassium and calcium
• Main results:
  • In crude fibers, magnesium, silicon and hydrogen were close to the expected values for ideal chrysotile (26.3, 20.2 and 1.44%).
  • In crude fibers, iron, manganese and nickel were almost constant within a mine but differed markedly between mines.
  • Manganese was the only analyzed element that distinguished all five mines; at a level of 0.05, the mean manganese concentrations were all statistically different.
  • Jeffrey mine chrysotile had distinctly high iron and low nickel values; Carey chrysotile contained little manganese or aluminum.
  • Cobalt and zinc were present at very low concentrations in crude fibers.
  • Calcium was the only divalent metal not detected in crude fibers, although it was easily measurable in host rock.
  • Milled fibers were enriched in metals by factors from 1.3 to more than 15 compared with crude fibers.
  • The authors attributed a 'normal' enrichment factor of 1.3 to milled fibers, based on manganese, zinc, cobalt and sodium.
  • Nickel, chromium and aluminum showed high and highly variable enrichment in milled fibers.
  • Iron content in milled fibers was increased by more than 100% over crude fibers.
  • The authors estimated that iron built into the crystal structure would account for as little as 30% of total iron.
  • The authors judged that the added iron could not be explained solely by wear from metal milling equipment.
  • Copper and calcium found in milled fibers indicated impurities.
• The authors' conclusion: The authors concluded that Quebec chrysotile has a definite content of a few metals that reflects its origin. Manganese and iron (crude fibers) and chromium and nickel (milled fibers) are potential markers for telling sources apart. In milled fibers, most of the metal content comes from non-chrysotile material, which they suggested could behave very differently biologically from the chrysotile fibers.
• Limitations the authors state:
  • For elements other than iron, manganese and nickel, the data were too few or too varied to allow comparison between mines and between analytical techniques.

Mines named here

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

• Bell Asbestos mine, Thetford Mines, Quebec
• Carey Canadian Mines, East Broughton, Quebec
• Cassiar mine, British Columbia
• Jeffrey mine, Asbestos, Quebec
• Lake Asbestos of Quebec, Black Lake, Quebec

All asbestos mines

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile.

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

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• Comparing milled fiber, Quebec ore, and textile factory dust: has another piece of the asbestos puzzle fallen into place? — D.W. Berman (2010)
• Letter to the editor: "Comparing milled fiber, Quebec ore, and textile factory dust: has another piece of the asbestos puzzle fallen into place?" by D. Wayne Berman — J.M. Dement, L.T. Stayner (2010)
• Asbestos and metals as carcinogens — T. Norseth (1980)

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