The diagnosis and attribution of asbestos-related diseases in an Australian context: report of the Adelaide Workshop on Asbestos-Related Diseases. October 6-7, 2000

Our plain-English summary of The diagnosis and attribution of asbestos-related diseases in an Australian context: report of the Adelaide Workshop on Asbestos-Related Diseases. October 6-7, 2000, by D.W. Henderson, M.L. Jones, N. De Klerk, et al (International Journal of Occupational and Environmental Health, 2004).

The study

• Authors: D.W. Henderson, M.L. Jones, N. De Klerk, J. Leigh, A.W. Musk, K.B. Shilkin, V.M. Williams
• Journal: International Journal of Occupational and Environmental Health
• Published: 2004;10(1):40-6
• Type of article: Consensus statement, Review
• Cited by: 15 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Predictions of future cases of mesothelioma in Australia to the year 2020 are in the order of a total of 10,000 new cases. Compensation claims are testing the attribution in a particular case between occupational asbestos exposure and lung cancer. The cost of the problem necessitates clarifying and standardizing the criteria for a confident diagnosis of asbestos-related disease. The possibility of differences in criteria that determine attribution of asbestos to a disease prompted a consensus meeting of pathologists, epidemiologists, physicians, oncologists, radiologists, and others to define current thinking and to agree on an Australian document based on the scientific evidence for establishing diagnoses and attribution data of asbestos-related diseases in Australia. The participants' findings are reported.

In plain English

This consensus report, not a new research study, came from the Adelaide Workshop on Asbestos-Related Diseases (AWARD). There, 15 participants, including epidemiologists, pathologists, physicians and radiologists, met in October 2000. They sought agreed Australian criteria for diagnosing asbestos-related diseases and attributing them to asbestos. The participants stated that no exposure threshold below which there is no mesothelioma risk had been identified. They also stated that the amphiboles crocidolite and amosite are substantially more potent than chrysotile for mesothelioma. They stated that attributing lung cancer to asbestos does not require asbestosis. They considered the Helsinki Criteria's 25 fibers/mL-year cumulative exposure a fair and reasonable approach for attributing lung cancer to asbestos after amphibole-only (except Wittenoom), mixed or asbestos textile exposures, given adequate latency. That level is generally associated with about a doubling of lung cancer risk. The workshop made no firm recommendation for a more definitive screening program. However, it considered that experimental screening might include former workers with substantial asbestos exposure and significant smoking histories. It noted that Australia had no job-exposure matrix. The authors concluded that, without more data, these benchmarks offered broadly acceptable parameters for Australia.

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: Consensus workshop report (expert agreement document summarizing existing scientific evidence; no new data collected)
• Who was studied: 15 workshop participants (epidemiologists, industrial hygienists, oncologists, pathologists, physicians, radiologists and other scientists) who met in Adelaide, Australia, in October 2000. One listed participant was based in New Zealand. Two officers of the Workers Compensation Dust Diseases Board NSW attended as observers and were not party to the document.
• Exposure: Asbestos exposure in general, particularly occupational exposure. The report discussed amphiboles (crocidolite, amosite) and chrysotile, cumulative exposure in fibers/mL-year, and lung fiber burden.
• Main results:
  • For mesothelioma, the participants stated that no minimum threshold of exposure has been delineated below which there is no risk.
  • The report stated general agreement that amphibole asbestos (commercially crocidolite and amosite) is substantially more potent than chrysotile for inducing mesothelioma.
  • The report stated that the majority of evidence and the prevailing expert view is that attribution of lung cancer to asbestos does not require asbestosis to be present.
  • The report stated that a cumulative exposure of 25 fibers/mL-year is generally associated with approximately a doubling of lung cancer risk in both smokers and non-smokers.
  • The participants considered the Helsinki Criteria requirement of 25 fibers/mL-year a fair and reasonable approach for attributing lung cancer to asbestos in three situations: amphibole-only exposures (except Wittenoom), mixed exposures, and asbestos textile exposures.
  • Given an adequate latency period, this cumulative exposure level has been widely used as an index that makes it more likely than not that asbestos contributed to a particular lung cancer.
  • Citing earlier work on the Wittenoom cohort (crocidolite), the report stated that a relative risk of 2.0 for lung cancer occurs at about 35 fibers/mL-year of exposure.
  • According to a generally held view and the Helsinki Criteria, a cumulative exposure of 25 fibers/mL-year or more correlates with about 500-1,500 asbestos bodies per gram of wet lung tissue.
  • The workshop made no firm recommendation for a more definitive lung cancer screening program.
  • The view at the meeting was that an experimental screening program might be extended to any former workers with substantial asbestos exposure and a significant smoking history, subject to their willingness to participate.
  • No threshold had been delineated for asbestos-related malignancies (mesothelioma and lung cancer). The report stated there is some evidence for a threshold for asbestosis and perhaps for diffuse pleural fibrosis.
  • The report stated that Australia had no job-exposure matrix system comparable to those in Germany and The Netherlands.
• The authors' conclusion: The participants considered that, in the absence of more finite data including cumulative exposure data, the benchmarks outlined in the paper offered broadly acceptable parameters in Australia at the time.
• Limitations the authors state:
  • Exposure matrices for Australian workers and the general population had not been determined.
  • Except for malignant mesothelioma, there was no accurate estimate of the extent of occupational cancers in Australia.
  • Better knowledge of exposure-response relationships for the various asbestos-induced diseases is needed.
  • Microanalytic (lung fiber counting) techniques were not standardized worldwide, which made it difficult to compare results between laboratories.

Topics

Medical terms in this study, explained in our Lexicon: Attribution, Mesothelioma, Asbestos Exposure, Lung Cancer.

Related studies

• Asbestos-related pleural disease in Western Australian gold-miners — Y.C. Lee, N.H. De Klerk, et al. (1999)
• Altered functions of alveolar macrophages and NK cells involved in asbestos-related diseases — Y. Nishimura, M. Maeda, et al. (2013)
• Asbestos-related cancers in refinery workers in the Australian petroleum industry — R. Gun, N.L. Pratt, et al. (2006)
• Recommendations for the Diagnosis and Management of Asbestos-Related Pleural and Pulmonary Disease — C. Diego Roza, M.J. Cruz Carmona, et al. (2017)
• Conventional and high resolution computed tomography in the diagnosis of asbestos-related diseases — D.A. Lynch, G. Gamsu, et al. (1989)
• Computed tomography in the diagnosis of asbestos-related thoracic disease — G. Gamsu, D.R. Aberle, et al. (1989)

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