First Identification of Pulmonary Asbestos Fibres in a Spanish Population

Our plain-English summary of First Identification of Pulmonary Asbestos Fibres in a Spanish Population, by M.I. Velasco-García, M.J. Cruz, C. Diego, et al (Lung, 2017).

The study

• Authors: M.I. Velasco-García, M.J. Cruz, C. Diego, M.A. Montero, D. Álvarez-Simón, J. Ferrer
• Journal: Lung
• Published: 2017;195(5):671-677
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Introduction: This study aimed to characterize, for the first time in Spain, the type of asbestos fibres (AF) in the lungs of exposed and non-exposed populations.

Materials And Methods: Lung samples from 38 subjects living in Barcelona and Ferrol, Spain, were studied, which were divided into three groups: Group A-five subjects without known respiratory disease; Group B-20 ex-shipyard workers and Group C-13 patients with lung cancer. After eliminating the organic material, the inorganic residue was analysed using electronic microscopy (EM). To identify the type of fibre, the samples were analysed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX).

Results: All the fibres identified corresponded to amphiboles (crocidolite 45%, anthophyllite 22%, tremolite 16%, amosite 15% and actinolite 3%). In 14 patients (37%), a single type of asbestos was found in the lungs (amosite in two, actinolite in one, anthophyllite in four, crocidolite in five and tremolite in two). Forty-six percent of the AF analysed had a length > 5 µm and a diameter < 0.2 µm.

Conclusions: The results of this study provide the first data on the type of asbestos retained in the lung of Spanish population. A particularly striking finding is the exclusive retention of amphiboles, which suggests that chrysotile is eliminated after inhalation. Our findings support estimations considering Spain and other southern European countries with similar asbestos imports and consumption at a high risk to develop asbestos-related diseases in the years to come.

In plain English

This Spanish study examined lung tissue from 38 people to identify which types of asbestos fibres remained in their lungs, using electron microscopy. There were three groups. The first was five Barcelona residents without known respiratory disease, examined at autopsy. The second was 20 former Ferrol shipyard workers who had been exposed to asbestos, also examined at autopsy. The third was 13 Barcelona lung cancer patients whose tissue was surgically removed. All fibres identified were amphiboles, and no chrysotile was found. Crocidolite was the most common type (45%). In 14 people (37%), only one asbestos type was found. The shipyard workers had a higher percentage of amosite. All 20 of them had more than 1000 asbestos bodies per gram of dry lung tissue. By comparison, none of the five residents and 6 of the 13 lung cancer patients reached that level. Forty-six percent of fibres were longer than 5 micrometres and thinner than 0.2 micrometres. The authors concluded that amphiboles appear to be almost exclusively retained in Spanish patients. They said this might apply to other southern European countries and reinforces estimates of Spain as a country at higher risk of asbestos-related diseases in the years to come.

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 lung-tissue fibre analysis study comparing three groups (autopsy and surgical samples), using light microscopy for asbestos bodies and scanning electron microscopy with energy-dispersive X-ray spectroscopy to identify fibre types
• Who was studied: 38 subjects in Spain. Group A: 5 Barcelona residents without known respiratory disease, autopsy samples collected June 2004 to June 2005 at the Institute of Legal Medicine of Catalonia. Group B: 20 former Ferrol shipyard workers, autopsy samples received 2008 to 2010. Group C: 13 Barcelona lung cancer patients operated at Vall d'Hebron Hospital.
• Exposure: Asbestos exposure was determined by interview. Group A: 0% exposed. Group B shipyard workers: 100% exposed, for a median of 27 years (range 13–44). Group C lung cancer patients: 23% exposed, with years of exposure not recorded.
• Main results:
  • In all 38 subjects, amphibole fibres made up 100% of the fibres recovered, and no chrysotile fibres were found.
  • Across all subjects, the fibres were crocidolite 45%, anthophyllite 22%, tremolite 16%, amosite 15% and actinolite 3%.
  • In 14 patients (37%), only one type of asbestos was found: amosite in two, actinolite in one, anthophyllite in four, crocidolite in five and tremolite in two.
  • Group B (shipyard workers) had a higher percentage of amosite than Groups A and C (p = 0.022 and 0.031).
  • Group A had a higher percentage of actinolite than Groups B and C (p = 0.012 and 0.023).
  • Group C (lung cancer patients) had a higher percentage of tremolite than Groups A and B (p = 0.011 and 0.017). The authors reported that tremolite made up 41% of asbestos in lung cancer patients, compared with 16% overall.
  • 72% of individuals in the Ferrol shipyard group mainly had crocidolite in their lung samples.
  • Median asbestos bodies per gram of dry lung tissue, counted by light microscopy: Group A 0 (range 0–599); Group B 14,647 (range 1327–4,660,059); Group C 326 (range 0–26,280). Group B was higher than Groups A and C, and Group C was higher than Group A.
  • More than 1000 asbestos bodies per gram of dry tissue (the level considered significant) was found in 0 of 5 (0%) in Group A, 20 of 20 (100%) in Group B and 6 of 13 (46%) in Group C.
  • Overall, 46% of the asbestos fibres analysed were longer than 5 micrometres and thinner than 0.2 micrometres. These fibres were mainly in the shipyard workers' samples.
  • Long, thin fibres (longer than 5 micrometres, thinner than 0.2) made up 49% of fibres in Group B, compared with 9% in Group A and 18% in Group C (table).
  • In all groups, 97% of the long, thin fibres were amosite.
• The authors' conclusion: The authors concluded that amphiboles appear to be almost exclusively retained in the lungs of Spanish patients, and that this finding might be extrapolated to other southern European countries. They said it reinforces estimates of Spain as one of the European countries at higher risk of asbestos-related diseases in the years to come.

Topics

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

Medical terms in this study, explained in our Lexicon: Lung Cancer, Scanning Electron Microscopy (SEM), Amphibole Group, Crocidolite, Anthophyllite, Tremolite, Amosite, Actinolite.

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