Rapporteur's Report Session 3: exposure to grunerite (amosite) asbestos: historical perspectives of the health effects

Our plain-English summary of Rapporteur's Report Session 3: exposure to grunerite (amosite) asbestos: historical perspectives of the health effects, by G.W. Gibbs (Regulatory Toxicology and Pharmacology, 2008).

The study

• Author: G.W. Gibbs
• Journal: Regulatory Toxicology and Pharmacology
• Published: 2008;52(1 Suppl):S91
• Read it: PubMed · Publisher

In plain English

This one-page rapporteur's report summarized a conference session on the health effects of grunerite asbestos (amosite). It is not a new study. The session reviewed three case series reports and one analytical report. South African data covered 504 proven mesothelioma cases. Of 129 cases with established occupational exposure and fiber type, 115 were linked to Cape crocidolite, 1 to Transvaal crocidolite, 9 to amosite and 4 to mixed fiber types. None were linked to chrysotile. A second paper reviewed insulation product factories in Paterson and Tyler (US) and Uxbridge (UK). Proportional mortality from mesothelioma ranged from 1.5% at the UK plant to 4.8% in one Paterson study, compared with 0.6% reported for South African amosite miners. About 50% of US and 20% of UK cases were peritoneal. Lung cancer risks were judged clearly increased. The author concluded that grunerite asbestos can increase lung cancer and mesothelioma risk and that Cape crocidolite poses a far greater mesothelioma risk. The author also concluded that chrysotile, based on the South African evidence, may not cause mesothelioma.

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: Rapporteur's report: a summary of the papers presented in one conference session, not original research
• Who was studied: 504 proven mesothelioma cases from South Africa, plus workers at insulation product factories in Paterson and Tyler (US) and Uxbridge (UK)
• Exposure: Occupational and environmental exposure to Cape crocidolite, Transvaal crocidolite, amosite (grunerite asbestos), mixed fiber types and chrysotile in South Africa, and amosite exposure in insulation product manufacturing. Exposure estimates in the US and UK plants ranged up to about 100 f/ml.
• Main results:
  • Sources of exposure among the South African cases: 28% occupational exposure in mining, 35% non-mining occupations, 23% environmental exposures, 14% no exposure established, 9% exposure unknown
  • Among the 129 cases with established occupational exposure and fiber type: 115 Cape crocidolite, 1 Transvaal crocidolite, 9 amosite (grunerite asbestos), 4 mixed fiber types
  • No South African cases were associated with chrysotile asbestos
  • Environmental mesothelioma cases: 33 linked to Cape crocidolite and 2 to amosite and crocidolite. None were linked to Transvaal amosite alone or to chrysotile.
  • All three insulation factories had increased proportional mortality from mesothelioma, ranging from 1.5% at the UK plant to 4.8% in one study at the Paterson plant
  • Approximately 50% of the US factory cases and 20% of the UK factory cases were peritoneal tumors
  • Proportional mortality for lung cancer was high enough in all factory cohorts to conclude that lung cancer risks were clearly increased
  • Proportional mortality for mesothelioma in South African amosite miners was reported as 0.6%. The author hypothesized that further fiberizing of amosite during manufacturing might be a factor in the apparently higher risk in processing than in mining.
• The authors' conclusion: The author concluded that grunerite asbestos can increase the risk of lung cancer and mesothelioma, that Cape crocidolite poses a far greater mesothelioma risk, and that chrysotile, based on the South African evidence, may not cause mesothelioma
• Limitations the authors state:
  • Data to compare exposure levels in mining (production) with those in manufacturing were not available
  • Asbestosis mortality is not always a reliably recorded outcome
  • Proportional mortality ratios are not the most reliable measure for examining lung cancer risk

Topics

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

Medical terms in this study, explained in our Lexicon: Grunerite, Amosite.

Related studies

• Rapporteur's Report Session 4: grunerite asbestos (amosite) and tremolite-ferroactinolite asbestos: risk of environmental mesothelioma — J.F. Gamble (2008)
• Human health effects associated with the commercial use of grunerite asbestos (amosite): Paterson, NJ; Tyler, TX; Uxbridge, UK — J. Ribak, G. Ribak (2008)
• Health effects of amosite mining and milling in South Africa — J. Murray, G. Nelson (2008)
• Rapporteur's Report Session 2: characterization of fibrous minerals — A.M. Langer (2008)
• Rapporteur's Report Session 6: risk assessment of asbestos and other fibrous mineral particulates — R.P. Nolan, A.M. Langer (2008)
• A risk assessment for exposure to grunerite asbestos (amosite) in an iron ore mine — R.P. Nolan, A.M. Langer, et al. (1999)

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