Short fiber tremolite free chrysotile mesothelioma cohort revealed

Our plain-English summary of Short fiber tremolite free chrysotile mesothelioma cohort revealed, by D. Egilman, T. Bird (American Journal of Industrial Medicine, 2016).

The study

• Authors: D. Egilman, T. Bird
• Journal: American Journal of Industrial Medicine
• Published: 2016;59(3):196-9
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

In 1995, Dell and Teta published a cohort mortality study of asbestos molding compound workers at a Union Carbide Corporation (UCC) plastics manufacturing plant in Bound Brook, New Jersey. They reported that the factory workers were exposed to "asbestos (mostly chrysotile)," implying that the asbestos used at the Bound Brook plant occasionally contained amphiboles. However, UCC statements and testimony from recent litigation indicate that the Bound Brook plant exclusively used short fiber chrysotile asbestos. These recent documents also point to lower exposures than those reported by Dell and Teta. This chrysotile-only cohort should be included in analyses of chrysotile potency.

© 2016 Wiley Periodicals, Inc.

In plain English

This article was a commentary, not a new study. The authors reviewed historic Union Carbide Corporation (UCC) memos and letters, released during asbestos litigation, along with recent deposition testimony about a UCC plastics plant in Bound Brook, New Jersey. A 1995 study of this plant's workers by Dell and Teta had reported ten pleural mesotheliomas and four cases of asbestosis, and had described the exposure as "asbestos (mostly chrysotile)." From their review, the authors concluded that the plant used only chrysotile. Most of it was short fiber from the Carey Canada mine, which a separate study had found to be tremolite free. A 1989 UCC message to the EPA had said one product contained crocidolite, but company witnesses later denied this under oath. The authors also found more air measurements than Dell and Teta had reported. These ranged from 0.3 to 14.1 fibers per cubic centimeter (f/cc), and all but one were under 5 f/cc. The authors concluded that this chrysotile-only group should be included in analyses of chrysotile potency.

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: Commentary reviewing company documents (historic UCC memos and letters) and deposition testimony from litigation; no new data were collected
• Who was studied: Workers at a Union Carbide Corporation plastics (Bakelite molding compound) plant in Bound Brook, New Jersey. They were the group previously studied by Dell and Teta in 1995, a study that reported ten pleural mesotheliomas and four asbestosis cases.
• Exposure: Short fiber chrysotile asbestos (type 7RF), mostly from the Carey Canada mine, used in Bakelite molding compounds
• Main results:
  • The authors' review indicated that the plant used only chrysotile asbestos.
  • The asbestos came mainly from the Carey Canada mine. A study cited by the authors found that mine to be tremolite free.
  • A UCC communication to the EPA had said that High Impact Heat Resistant Bakelite contained crocidolite. Company representatives later denied this in deposition testimony.
  • Dell and Teta had reported only one measurement, from 1968: dust levels of 8.7 to 20.1 million particles per cubic foot. The authors estimated this as approximately 1.45 to 3.35 f/cc.
  • Other UCC measurements ranged from 0.3 to 14.1 f/cc. All were under 5 f/cc except the single 14.1 f/cc reading, taken while an operator wearing a respirator was dumping bags of molding compound.
  • In 1974, eight-hour time-weighted average exposures were 1.3 to 1.6 f/cc for workers during bag dumping and 0.7 to 1.1 f/cc for charge roll operators. The bag packer's exposure was 0.3 fibers per milliliter.
• The authors' conclusion: The authors concluded that the Bound Brook data show a risk at lower chrysotile exposure levels than previously reported. They stated that this chrysotile-only cohort should be included in analyses of chrysotile potency, and that the new information might require lowering the "no-effect" level for chrysotile carcinogenicity.
• Limitations the authors state:
  • The authors stated that UCC's air monitoring probably overestimated actual asbestos exposure, because non-asbestos fibers were present during some production.

Topics

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

Medical terms in this study, explained in our Lexicon: Tremolite, Chrysotile, Mesothelioma, Union Carbide, Bound Brook, Amphibole Group.

Related studies

• An elaboration of "proof" of peritoneal mesothelioma from tremolite free chrysotile — D. Egilman (2011)
• Comparison of Calidria chrysotile asbestos to pure tremolite: final results of the inhalation biopersistence and histopathology examination following short-term exposure — D.M. Bernstein, J. Chevalier, et al. (2005)
• Comparison of Calidria chrysotile asbestos to pure tremolite: inhalation biopersistence and histopathology following short-term exposure — D.M. Bernstein, J. Chevalier, et al. (2003)
• Historical cohort study of US man-made vitreous fiber production workers: II. Mortality from mesothelioma — G.M. Marsh, M.J. Gula, et al. (2001)
• The Production of Corporate Research to Manufacture Doubt About the Health Hazards of Products: An Overview of the Exponent Bakelite® Simulation Study — D. Egilman (2018)
• Assessing specific causation of mesothelioma following exposure to chrysotile asbestos-containing brake dust — M.D. Freeman, S.S. Kohles (2012)

Browse more research in American Journal of Industrial Medicine, or return to medical research.