Measurement of asbestos fibre concentrations in fluid of repeated bro-choalveolar lavages of exposed workers

Our plain-English summary of Measurement of asbestos fibre concentrations in fluid of repeated bro-choalveolar lavages of exposed workers, by P. Sartorelli, R. Romeo, G. Scancarello, et al (The Annals of Occupational Hygiene, 2007).

The study

• Authors: P. Sartorelli, R. Romeo, G. Scancarello, L. Montomoli, C. Muzzupappa, L. Barabesi
• Journal: The Annals of Occupational Hygiene
• Published: 2007;51(5):495-500
• Cited by: 9 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objectives: The aim of this study was to assess the reliability of asbestos fibre concentration in bronchoalveolar lavage fluid (BALF) by carrying out the mineralogical analysis of BALF at different times in the same patient and comparing the results.

Methods: Twenty two patients underwent diagnostic fibreoptic bronchoscopy twice: the first was to assess the past asbestos exposure and the second for different clinical reasons. Mineralogical analysis of BALF was carried out.

Results: In 16 patients (72.7%), a reduction of concentration in BALF of all asbestos fibres was observed. The concentrations of both chrysotile and amphiboles in the first bronchoalveolar lavage (BAL) were related to their concentrations in the second BAL and the observed differences were not statistically significant. A significant decrease in asbestos body concentration between the first and the second BAL was found (Wilcoxon test, P < 0.01).

Conclusions: The reliability of the fibre concentration in BALF as a marker of past asbestos exposure seems quite good. In most cases, it allows us to distinguish workers in different classes of exposure and gives useful information on the pattern of exposure. Uncertainties related in general to lung residues and in particular to mineralogical analysis of BALF (mainly due to the high coefficient of variation (CV) at low fibre concentrations and the results of the statistical analysis on total fibres) suggest that this biomarker is more likely suitable for a qualitative/categorical approach to exposure assessment than a quantitative one.

In plain English

This Italian study tested whether measuring asbestos in fluid washed out of the lungs (bronchoalveolar lavage fluid) gives consistent results when the test is repeated in the same person. The authors studied 22 men who had been exposed to asbestos at work, mainly in electric energy production, railway rolling stock production, shipbuilding yards and the steel industry. Each man had one lavage to assess past exposure and a second one, on average 4.0 years later, for other clinical reasons. Total asbestos fibre concentration fell in 16 patients (72.7%), but the overall difference was at the limit of statistical significance (P = 0.05). For chrysotile alone (P = 0.19) and amphiboles alone (P = 0.10) the differences were not statistically significant. Asbestos body concentration fell significantly between the two lavages (P less than 0.01, in 17 subjects). Only two of the 22 men (9.1%) moved from one of the authors' exposure categories to another. The authors concluded that fibre concentration seems a reliable marker of past exposure. Because results vary widely at low concentrations, they judged it better suited to sorting workers into exposure categories than to exact quantitative estimates.

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: Repeatability study with paired measurements: two bronchoalveolar lavages, some years apart, in the same previously exposed workers
• Who was studied: 22 men drawn from 193 occupationally exposed workers hospitalized over 12 years at the Section of Occupational Medicine and Toxicology, University of Siena, Italy, for suspected asbestos-related diseases. Their exposure had ceased before the first lavage. The mean time between lavages was 4.0 years (range 1 to 10).
• Exposure: Past occupational asbestos exposure in electric energy production (36.4%), railway rolling stock production (22.7%), shipbuilding yards (9.1%), the steel industry (9.1%) and other fields (22.7%). Chrysotile fibres, amphibole fibres and asbestos bodies were measured in lavage fluid.
• Main results:
  • In 16 of the 22 patients (72.7%), concentration of all asbestos fibres was lower in the second lavage. The joint (overall) test gave P = 0.05.
  • Tested separately, the differences between the first and second lavage were not statistically significant: P = 0.19 for chrysotile and P = 0.10 for amphiboles.
  • Chrysotile concentrations in the first and second lavage were linearly related (R2 = 0.63). Second-lavage values were about 60% of first-lavage values. Amphiboles showed a similar pattern (R2 = 0.64, also about 60%).
  • The change in fibre concentration did not depend on the time between the two lavages, for either chrysotile or amphiboles.
  • Asbestos body concentration decreased significantly between the first and second lavage (one-sided Wilcoxon test, P less than 0.01). This was analysed in 17 subjects.
  • Exposure categories based on total fibre concentration:
• 16 subjects were above 650 fibres per ml in both lavages.
• Four were between 182 and 650 in both.
• Only two (9.1%) changed category (from 991 to 546 and from 607 to 765).
• None were below 182.
• The authors' conclusion: The authors concluded that fibre concentration in lavage fluid seems a reliable marker of past asbestos exposure. They judged its repeatability good for chrysotile and amphiboles considered separately, and sufficient for total fibre concentration.
• Limitations the authors state:
  • Measurement variability was high at very low fibre concentrations (coefficient of variation up to 65%). The authors therefore considered the marker more suitable for a qualitative or categorical approach than a quantitative one.
  • Repeatability of asbestos body counts was not as good as that of electron microscopy fibre analysis. In two subjects, asbestos bodies were below the detection limit in the first lavage but positive in the second.
  • The mean 4-year interval between lavages may have been too short to affect fibre concentration. The authors noted that lung clearance needs specific research.
  • Asbestos body data were missing for 5 of the 22 patients.

Topics

Medical terms in this study, explained in our Lexicon: Bronchoalveolar Lavage (BAL), Bronchoscopy, Asbestos Exposure, Chrysotile, Amphibole Group, Asbestos Bodies, Biomarker.

Related studies

• Asbestos exposure assessment by mineralogical analysis of bronchoalveolar lavage fluid — P. Sartorelli, G. Scancarello, et al. (2001)
• Erionite bodies and fibres in bronchoalveolar lavage fluid (BALF) of residents from Tuzköy, Cappadocia, Turkey — P. Dumortier, L. Coplü, et al. (2001)
• Asbestos bodies in bronchoalveolar lavage in relation to asbestos bodies and asbestos fibres in lung parenchyma — A. Karjalainen, R. Piipari, et al. (1996)
• Fibres and asbestos bodies in bronchoalveolar lavage fluids of asbestos sprayers — T. Tuomi, P. Oksa, et al. (1992)
• A study of the length and diameter of fibres, in lung and in broncho-alveolar lavage fluid, following exposure of rats to chrysotile asbestos — E. Kauffer, J.C. Vigneron, et al. (1987)
• 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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