S fibers

Our plain-English summary of S fibers, by M. Greenberg (American Journal of Industrial Medicine, 1984).

The study

• Author: M. Greenberg
• Journal: American Journal of Industrial Medicine
• Published: 1984;5(5):421-2
• Type of article: Letter
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

In this letter, Greenberg objected to the term "S Fiber", an eponym for the hypothesis of Stanton. He said the term had entered public debate on the regulation of mineral fibers in recent years. He wrote that the term had become associated with claimed "truths": that durable mineral fibers shorter than 8 µm, with diameters greater than variously 0.25 µm or 1.5 µm, are not carcinogenic, and that fiber shape determines carcinogenicity regardless of chemistry. He argued this ignored the careful writing of Stanton et al (1981) and balanced reviews such as Harington (1981). He quoted 1977 personal correspondence in which Stanton said his data pointed to the most carcinogenic dimensional range but said little about the least carcinogenic. In that correspondence Stanton reported that 13 dimensional ranges of crocidolite had been studied, and that two samples were highly carcinogenic although they apparently contained few fibres over 8 µm long. Greenberg also quoted Stanton et al (1981): tumor probability more likely falls as particle diameter increases and length decreases, rather than following a narrow carcinogenic size range. He noted that the two crocidolite samples were never fully explained. He cited a preliminary report by Kolev (1982) that found more tumors with amorphous than with fibrous crocidolite. He concluded that the term "S Fibers" should be abandoned because it had led to gross misconception about the hazards of fibrous minerals.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This was a letter to the journal, not a research study, and reported no new data. The author objected to the term "S fiber", which the letter said had entered debate on regulating mineral fibers. The letter said the term had become linked to claims that durable mineral fibers shorter than 8 micrometres, with diameters greater than 0.25 or 1.5 micrometres, are not carcinogenic, and that fiber shape decides carcinogenicity regardless of chemistry. Arguing that these claims misread Stanton's work, the author quoted a 1977 personal letter from Stanton. Stanton wrote that the data pointed to the most carcinogenic size range but said little about the least carcinogenic sizes. Stanton also wrote that two crocidolite samples were highly carcinogenic though apparently containing few fibers over 8 micrometres, so the material must be re-examined. The letter also quoted Stanton et al (1981): rather than a narrow carcinogenic size range, it was perhaps more likely that tumor probability falls as diameter increases and length decreases. It cited a preliminary report by Kolev (1982) of more tumors with amorphous than with fibrous crocidolite. The author proposed abandoning the term.

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: letter to the editor (commentary), not an original study
• Who was studied: no study population; the letter comments on other researchers' work on mineral fiber dimensions
• Exposure: durable mineral fibers by size and shape, including crocidolite; the letter discusses claims that fibers shorter than 8 micrometres with diameters greater than 0.25 or 1.5 micrometres are not carcinogenic, and that shape rather than chemistry determines carcinogenicity
• Main results:
  • The letter quoted Stanton's 1977 personal correspondence saying the data identified the most carcinogenic size range but said little about which sizes are least carcinogenic (Stanton's statement, not a finding of this letter)
  • In the same correspondence, Stanton reported that two crocidolite samples were highly carcinogenic although they apparently contained few fibers over 8 micrometres long, and said the material must be re-examined (Stanton's statement)
  • The letter quoted Stanton et al (1981) as suggesting that, rather than a narrow size range outside which particles are not carcinogenic, it was perhaps more likely that tumor probability falls as fiber diameter increases and length decreases
  • The letter cited a preliminary report by Kolev (1982) that observed more tumors with amorphous crocidolite than with fibrous crocidolite (Kolev's finding, not this letter's)
• The authors' conclusion: The author proposed that the term "S Fibers" be abandoned, saying its adoption had led to gross misconception about current knowledge of the hazards of fibrous minerals

Topics

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

Medical terms in this study, explained in our Lexicon: Mineral Fiber, Carcinogenic, Crocidolite.

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