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

Our plain-English summary of 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, by J.M. Dement, L.T. Stayner (Critical Reviews in Toxicology, 2010).

The study

• Authors: J.M. Dement, L.T. Stayner
• Journal: Critical Reviews in Toxicology
• Published: 2010;40(8):749-51; author reply 752-7
• Type of article: Comment, Letter
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This was a letter to the editor, not a new study. The authors responded to a 2010 article by D. Wayne Berman. They agreed with Berman that airborne fiber sizes in textile mills were very different and might explain differing findings between studies of textile workers and miners. They disagreed with his use of their transmission electron microscope (TEM) data from the Charleston, South Carolina, asbestos textile plant to conclude that fiber sizes vary little between operations within an industry. They argued that he analyzed the 83 samples one by one, against their study design. They also said he appeared to use a fiber density method that would give heavily loaded filters much more weight. They reported that a likelihood-ratio chi-square test comparing departments strongly rejected the idea of no difference (p less than .001). They also cited 1938 and 1966 studies showing longer fibers in weaving than in fiber preparation. They cited their own earlier analyses, in which longer and thinner fibers were stronger risk predictors. The authors concluded that Berman had not convincingly shown that fiber sizes were the same across textile departments.

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 critiquing another author's article)
• Who was studied: No new study population. The letter discusses Berman's re-analysis of the letter authors' 83 TEM air samples from the Charleston, South Carolina, asbestos textile plant.
• Exposure: Airborne asbestos fibers in asbestos textile mill departments, characterized by fiber size (length and diameter) using TEM analyses of archived membrane filters. Berman's experiments used Grade 3 chrysotile.
• Main results:
  • The authors stated that Berman calculated size distributions for each of the 83 individual TEM samples. Their study design had required combining samples within a department.
  • The authors stated that it appeared Berman combined samples in his regrouped hypothetical zones using his fiber density method. They said this method would give filters with very high fiber loading much more weight.
  • The authors reported that a likelihood-ratio chi-square test comparing fiber size distributions across departments of the Charleston plant strongly rejected the null hypothesis of no difference (p less than .001).
  • Cited earlier study (Dreessen et al., 1938, North Carolina asbestos textile plants), not this letter: mean fiber length ranged from 7.0 μm in fiber preparation (willowing) to 16.3 μm in weaving.
  • Cited earlier study (Lynch and Ayer, 1966, US asbestos mills), not this letter: fibers longer than 10 μm were 18.6% of airborne PCM-counted fibers in fiber preparation and 38.7% in weaving.
  • Cited earlier study by the authors' group (Stayner et al., 2008), on asbestosis and lung cancer risk by fiber size: all fiber size categories were significant risk predictors, but longer and thinner fibers were stronger predictors.
• The authors' conclusion: The authors concluded that Berman had not convincingly shown that airborne fiber sizes were the same across textile departments. They said his elutriator method had merit for comparing bulk fiber between industries, but could not detect size differences within a sector without additional considerations.
• Limitations the authors state:
  • The authors acknowledged that the earlier textile mill studies they cited did not use TEM analyses.
  • The authors stated that more research is needed to determine whether fiber size variability is greater between industries than within industries.

Related studies

• Comparing milled fiber, Quebec ore, and textile factory dust: has another piece of the asbestos puzzle fallen into place? — D.W. Berman (2010)
• SV40, growth factors, and mesothelioma: another piece of the puzzle — B.T. Mossman, D.C. Gruenert (2002)
• Estimates of historical exposures by phase contrast and transmission electron microscopy in North Carolina USA asbestos textile plants — J.M. Dement, D. Myers, et al. (2009)
• Development of a fibre size-specific job-exposure matrix for airborne asbestos fibres — J.M. Dement, E.D. Kuempel, et al. (2008)
• Environmental measurements of total dust and fiber concentration in manufacturer and user of man-made mineral fibers — J.H. Kim, H.S. Chang, et al. (1999)
• Potential pulmonary effects of man-made organic fiber (MMOF) dusts — D.B. Warheit, G.A. Hart, et al. (2001)

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