Polymers as selective antagonists of hemolytic asbestos fibers

Our plain-English summary of Polymers as selective antagonists of hemolytic asbestos fibers, by R.J. Schnitzer, G. Bunescu (Archives of Environmental Health, 1970).

The study

• Authors: R.J. Schnitzer, G. Bunescu
• Journal: Archives of Environmental Health
• Published: 1970;20(4):481-2
• Cited by: 18 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 test-tube experiment; it did not study people or animals. The authors compared two chrysotile asbestos samples from the Jeffrey Mines, Quebec, Canada. Sample A was unaltered; Sample B was heated at 1,000 C for one hour. They measured how strongly each burst sheep red blood cells (hemolysis) and whether two polymers, sodium carboxymethyl cellulose (CMC) and polyvinylpyridine-N-oxide (PVPNO), blocked this. Both samples were hemolytic. Half the cells burst at 0.15 mg/ml of unheated and 1.48 mg/ml of heated chrysotile. For unheated chrysotile, CMC cut hemolysis by half at concentrations from 0.0098 mg per ml, depending on fiber dose. The text gives the top of that range as 0.27, but the table appears to show 0.027. PVPNO needed concentrations 22 to more than 100 times greater. For heated chrysotile, CMC was inactive even at high concentration, but PVPNO cut hemolysis by half at 0.0068 mg/ml, a pattern like quartz. The authors concluded the two materials burst cells in different ways. They said heated asbestos may have different disease effects, though whether lower or higher could not be predicted.

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 (in vitro) experiment measuring red blood cell destruction (hemolysis) by asbestos fibers and its inhibition by polymers
• Who was studied: Sheep red blood cells in test tubes (no human or animal subjects)
• Exposure: Two chrysotile samples from the Jeffrey Mines (Quebec, Canada), obtained from the Johns-Manville Research and Development Center. Sample A was unaltered air-jet milled fiber. Sample B was the same material heated at 1,000 C for one hour. Two polymers were tested as inhibitors: sodium carboxymethyl cellulose (CMC) and polyvinylpyridine-N-oxide (PVPNO).
• Main results:
  • Unheated chrysotile (Sample A): the concentration bursting 50% of cells was 0.15 mg/ml
  • Heated chrysotile (Sample B): the concentration bursting 50% of cells was 1.48 mg/ml
  • For unheated chrysotile (Sample A), CMC reduced hemolysis by half (50% inhibiting concentration) at concentrations from 0.0098 mg per ml, depending on fiber dose. The Results text gives the upper end as 0.27 mg per ml, but the table appears to list 0.027 mg/ml as the highest CMC value for Sample A.
  • For unheated chrysotile, PVPNO needed concentrations 22 to more than 100 times greater than CMC
  • Heated chrysotile (Sample B) showed the same pattern of response to inhibitors as silicon dioxide (quartz)
  • For heated chrysotile (Sample B), CMC was inactive at high concentration. PVPNO reduced hemolysis by half (50% inhibiting concentration) at 0.0068 mg/ml, the same order of magnitude seen with microquartz.
• The authors' conclusion: The authors concluded that heated and unheated chrysotile burst red blood cells by processes that are not identical, because different polymers selectively blocked each. They suggested that the surface of the two materials and the polymer structure may explain the difference. They also said heated asbestos may have disease effects different from the original material.
• Limitations the authors state:
  • The authors stated that it could not be predicted whether the disease potential of heated asbestos would be lower or higher than that of the original material
  • The authors stated that the mechanism by which CMC blocks chrysotile hemolysis is uncertain

Mines named here

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

• Jeffrey mine, Asbestos, Quebec

All asbestos mines

Related studies

• A comparative study on the hemolytic action of short asbestos fibers on human, rat, and sheep erythrocytes — J.P. Pelé, R. Calvert (1983)
• The hemolytic activity of chrysotile asbestos fibers: a freeze-fracture study — J.P. Pelé, J. Dunnigan, et al. (1983)
• Mount St. Helens' volcanic ash: hemolytic activity — V. Vallyathan, M.S. Mentnech, et al. (1983)
• Pleading for the use of biodegradable polymers in favor of marine environments and to avoid an asbestos-like problem for the future — M. Kubota, K. Takayama, et al. (2005)
• Polymer coating on carbon nanotubes into Durobeads is a novel strategy for human environmental safety — F. Ito, H. Hisashi, et al. (2018)
• Surface charge and hemolytic activity of asbestos — W.G. Light, E.T. Wei (1977)

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