Letter to the Editor regarding the Donovan et al. (2011) article

Our plain-English summary of Letter to the Editor regarding the Donovan et al. (2011) article, by D. Egilman, J.H. Schilling (Critical Reviews in Toxicology, 2012).

The study

• Authors: D. Egilman, J.H. Schilling
• Journal: Critical Reviews in Toxicology
• Published: 2012;42(2):169-72; author reply 173-83
• Type of article: Letter, Comment
• Read it: PubMed · Publisher

In plain English

This is a letter to the editor, not a research study. Its authors criticized a 2011 review by Donovan and colleagues of asbestos exposures to bystanders, meaning people near a worker handling an asbestos product. The letter's authors argued that the review's conclusions came wholly from an indoor air dispersion model (Drivas et al., 1996) that, according to the letter, was developed for asbestos litigation defense and was missing from the review's reference list. They noted that the review itself found no clear trend between bystander exposure and distance from the worker. They argued that capping bystander-to-worker ratios at 1 skewed the results downward. They cited earlier field studies as contradicting the review's 50-foot cutoff, including a reading of 46 f/cc at 75 feet from spray insulators reported by Reitze et al. (1972). They also questioned the review's fiber falling rate, its fiber widths, its use of "professional judgment," and its funding by companies involved in asbestos litigation. The authors concluded that the review's findings "are of no value."

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 critiquing a published literature review and modeling analysis (Donovan et al., 2011). It is not an original study.
• Who was studied: No people were studied. The letter discusses the Donovan et al. (2011) review and the 19 field studies it analyzed, 12 of which were simulation studies.
• Exposure: Asbestos exposure of bystanders near workers handling asbestos products in occupational settings. The examples discussed include spray insulation, grinding brake linings, blowing dust from brake drums and cutting asbestos cement pipe.
• Main results:
  • The letter's authors argued that the review's conclusions derive wholly from an indoor air dispersion model, which they describe as developed for asbestos litigation defense.
  • The letter quotes the review itself as finding no discernible trend when bystander-to-worker ratios were plotted against distance from the primary worker.
  • The letter's authors argued that capping bystander-to-worker ratios at 1 pushed the review's mean ratios lower and misrepresented the data.
  • As evidence against the review's 50-foot cutoff, the letter cites Reitze et al. (1972), which reported 46 f/cc at 75 feet from spray insulators. The letter states this was within the range of mean worker samples (35.2 to 61 f/cc).
  • The letter also cites Lorimer et al. (1976), which reported 0.2 f/cc at 60 feet from a worker grinding brake linings. The letter describes this as 5.3% of the source concentration.
  • The letter's authors questioned the review's falling rate of 33.1 ft/hour for fibers, contrasting it with EPA settling-time estimates.
  • Citing other studies of fiber widths, the letter's authors argued that the review's assumed fiber widths do not cover widths that can cause mesothelioma.
  • The letter points out that the Drivas et al. (1996) model, which it describes as central to the review, was not listed in the review's references.
  • The letter states that all of the review's authors were employees of Chemrisk, L.L.C., and that the review was supported by companies involved in asbestos litigation.
• The authors' conclusion: The letter's authors concluded that the issues they raised show the Donovan et al. findings are of no value. They added that the review's authors should have been required to cite the Drivas et al. (1996) model.
• Limitations the authors state:
  • The letter's authors state that their critique is far from complete.

Related studies

• Response to a letter to the editor by Dr. Murray M. Finkelstein regarding the article by Finley et al. (2012) — B.L. Finley, J.S. Pierce, et al. (2013)
• Letter to the Editor regarding Bullock 2020 — D. Egilman, B. Castleman, et al. (2020)
• Response to Letter to the Editor Regarding "Ambient Asbestos Fiber Concentrations and Long-Term Trends in Pleural Mesothelioma Incidence Between Urban and Rural Areas in the United States (1973-2012)" by Finkelstein — K.A. Keeton, M.E. Glynn, et al. (2018)
• Authors' response to Finkelstein's letter to the editor regarding our recent review of ambient airborne asbestos concentrations (Abelmann et al., 2015) — A. Abelmann, M.E. Glynn, et al. (2016)
• Author's response to: "Letter to the Editor" regarding content of "Mesothelioma from asbestos exposures: Epidemiologic patterns and impact in the United States" by R. A. Lemen, Journal of Toxicology and Environmental Health, Part B 2016; 19: 250-265 — (2017)
• Letter to Editor regarding Franzblau et al. 2020: Asbestos-containing materials in abandoned residential dwellings in Detroit, Science of Total Environment, v714,1-8 — A.L. Frank (2020)

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