Pleural mesothelioma and exposure to asbestos: evaluation from work histories and analysis of asbestos bodies in bronchoalveolar lavage fluid or lung tissue in 131 patients

Our plain-English summary of Pleural mesothelioma and exposure to asbestos: evaluation from work histories and analysis of asbestos bodies in bronchoalveolar lavage fluid or lung tissue in 131 patients, by J.C. Pairon, E. Orlowski, Y. Iwatsubo, et al (Occupational and Environmental Medicine, 1994).

The study

• Authors: J.C. Pairon, E. Orlowski, Y. Iwatsubo, M.A. Billon-Galland, G. Dufour, S. Chamming's, C. Archambault, J. Bignon, P. Brochard
• Journal: Occupational and Environmental Medicine
• Published: 1994;51(4):244-9
• Cited by: 26 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Exposure to asbestos was evaluated in 131 patients with pleural malignant mesothelioma in the Paris area between 1986 and 1992 using data from a detailed specific questionnaire and light microscopy analysis of the retention of asbestos bodies in bronchoalveolar lavage fluid or lung tissue. Probable or definite exposure to significant levels of asbestos dust was identified in only 48 (36.6%) subjects, and significant asbestos body counts (above 1 asbestos body/ml in bronchoalveolar lavage fluid or 1000 asbestos bodies/g of dry lung tissue) were found in only 45 (34.3%) subjects. Overall 50 subjects had experienced exposure to only low levels of asbestos or no exposure at all and showed no significant retention of asbestos bodies in the biological sample analysed. Previous studies have shown that light microscopy may be useful in the identification of subjects with previous exposure to asbestos. In this study, apart from cases with obvious exposure to asbestos, a large group of subjects seemed to have a history of exposure or lung retention of asbestos bodies suggestive of very low levels of cumulative exposure, similar to those described in the general population.

In plain English

The authors studied asbestos exposure in 131 patients with pleural malignant mesothelioma in the Paris area, diagnosed between 1986 and 1992. Patients answered a detailed work-history questionnaire. Two of the authors, who did not know the laboratory results, rated each patient's exposure into four classes (0 to 3). Asbestos bodies were counted by light microscopy in bronchoalveolar lavage (BAL) fluid (95 patients) or lung tissue (36 patients). Only 48 patients (36.6%) were in class 3, meaning regular exposure to at least medium levels, while 67 (51.1%) had low or no exposure. Only 45 (34.3%) had counts above the thresholds used: more than 1 asbestos body per ml of BAL fluid or 1000 per gram of dry lung tissue. Fifty patients had low or no exposure and no significant retention. Lung tissue counts differed significantly between exposure classes, but BAL counts did not. The authors concluded that the role of low cumulative exposure or other causes remained to be elucidated. They noted that electron microscopy fiber counts were not available.

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: Descriptive study of a series of mesothelioma patients (mostly cases from a case-control study), comparing questionnaire-based exposure ratings with light-microscopy asbestos body counts
• Who was studied: 131 patients with histologically confirmed pleural malignant mesothelioma in the Paris area: 116 cases from a case-control study (January 1987 to December 1992) who had a lung tissue or BAL sample, plus 15 patients diagnosed at the Centre Hospitalier Intercommunal de Creteil (January 1986 to December 1992). 16 were women and the rest men. Mean age at diagnosis was 61.6 years (range 37 to 84).
• Exposure: Asbestos exposure (fiber type not determined). It was rated from a standardised occupational questionnaire into four classes (0 to 3) based on probability, level and frequency of exposure. Asbestos bodies were counted by light microscopy in BAL fluid or lung tissue.
• Main results:
  • 67 of 131 patients (51.1%) had only low exposure or no exposure, according to the questionnaire (classes 0 and 1).
  • Only 48 patients (36.6%) were in class 3: regular, probable or definite exposure to at least medium levels.
  • Only 45 patients (34.3%) had asbestos body counts above the significance thresholds (more than 1 per ml of BAL fluid or 1000 per g of dry lung tissue).
  • 50 patients had low or no exposure and no significant asbestos body retention. Of these, 29 patients (22.1%) had no history of asbestos exposure at all and no significant retention.
  • Lung tissue counts differed significantly between the four exposure classes, with class 3 the highest. BAL fluid counts showed no significant difference between classes.
  • Significant retention was found in a smaller share of BAL fluid samples (27.4% of 95) than lung tissue samples (52.8% of 36).
  • Asbestos body counts were not significantly correlated with cumulative duration of exposure (r = 0.11 for BAL fluid, 0.33 for lung tissue).
  • In class 3 patients, counts fell as time since the end of exposure increased (r = -0.31, p = 0.053 for BAL fluid; r = -0.53, p = 0.13 for lung tissue).
• The authors' conclusion: The authors concluded that low indices of exposure were found in this series and that the role of low cumulative exposure (continuous low-level or sporadic peak exposure) or other causes remains to be elucidated.
• Limitations the authors state:
  • Counts of uncoated fibres by transmission electron microscopy were not available for this series.
  • Asbestos bodies may have been partly cleared from the lungs over the long time since exposure ended, so earlier retention could be underestimated.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Asbestos Bodies, Bronchoalveolar Lavage (BAL), Malignant Mesothelioma, Asbestos Body Formation, Cumulative Exposure.

Related studies

• Pleural plaques, asbestos exposure, and asbestos bodies in bronchoalveolar lavage fluid — E. Orlowski, J.C. Pairon, et al. (1994)
• Erionite bodies and fibres in bronchoalveolar lavage fluid (BALF) of residents from Tuzköy, Cappadocia, Turkey — P. Dumortier, L. Coplü, et al. (2001)
• Fibres and asbestos bodies in bronchoalveolar lavage fluids of asbestos sprayers — T. Tuomi, P. Oksa, et al. (1992)
• Diagnostic value of asbestos bodies in bronchoalveolar lavage fluid — P. De Vuyst, P. Dumortier, et al. (1987)
• Asbestos bodies in bronchoalveolar lavage fluid in relation to occupational history — A. Karjalainen, S. Anttila, et al. (1994)
• Asbestos bodies in bronchoalveolar lavage fluids of brake lining and asbestos cement workers — P. Dumortier, P. De Vuyst, et al. (1990)

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