Asbestos Burden in Lungs of Subjects Deceased From Mesothelioma Who Lived in Proximity to an Asbestos Factory: A Topographic Post-Mortem SEM-EDS Study

Our plain-English summary of Asbestos Burden in Lungs of Subjects Deceased From Mesothelioma Who Lived in Proximity to an Asbestos Factory: A Topographic Post-Mortem SEM-EDS Study, by S.D. Visonà, M. Untalan, B. Bertoglio, et al (American Journal of Industrial Medicine, 2025).

The study

• Authors: S.D. Visonà, M. Untalan, B. Bertoglio, S. Capella, E. Belluso, M. Billò, T. Ivic-Pavlicic, E. Taioli
• Journal: American Journal of Industrial Medicine
• Published: 2025;68(2):112-121
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Asbestos exposure and its pathological consequences, especially malignant mesothelioma (MM) still represent a major public health problem on a global scale. After the ban of asbestos in most western countries, nonoccupational exposure plays an essential role in MM pathogenesis. However, few studies have quantified asbestos lung burden after environmental exposure. The main objective of this work is to understand if asbestos lung content is different between occupationally and environmentally exposed individuals, and if the distance between the subjects' residences and the source of exposure is significantly associated with the asbestos lung burden.

Methods: In this retrospective, observational study we quantified, with analytical scanning electron microscopy, asbestos content in lungs of individuals deceased from MM between 2005 and 2019, who were exposed to asbestos (occupationally and/or environmentally) in Broni, a small town in northern Italy where an important asbestos-cement plant operated until 1993.

Results: We analyzed asbestos lung content of 77 subjects. We found that the asbestos lung content in MM patients who lived around the asbestos factory was as high as that seen in occupationally exposed individuals; this holds true in residents up to 10 km radius from the factory. We found no significant associations between the residence duration/distance ratio and asbestos lung burden.

Conclusions: This study suggests that heavy asbestos pollution involves not only the area adjacent to the factory, but the entire town of Broni and the surroundings. This is alarming if we consider that most asbestos factories still active in some countries are located close to towns and dwellings.

© 2024 The Author(s). American Journal of Industrial Medicine published by Wiley Periodicals LLC.

In plain English

This retrospective, observational study measured asbestos in autopsy lungs of 77 people who died of malignant mesothelioma (75 pleural, 2 peritoneal). Most were exposed in or around Broni, northern Italy, where the Fibronit asbestos-cement factory, active until 1993, used mainly chrysotile and crocidolite, with less amosite. Thirty-seven had occupational exposure and 40 had environmental exposure from living near the factory. Using scanning electron microscopy, the authors found no significant difference in total asbestos fibers between the groups (medians 14,740.00 versus 10,262.64 fibers per gram of dry lung). Amosite was significantly higher in the occupational group, including after adjustment for age and sex. Asbestos bodies were higher in the occupational group, but not after adjustment. Chrysotile/asbestiform antigorite, which the method cannot tell apart, was found in only 5 of 77. Among 39 environmental cases within 10 km, residence duration divided by distance was not significantly associated with lung asbestos, and distance correlated only with asbestos bodies. The authors concluded that the findings suggest heavy pollution reached the whole town and surroundings. They noted that lung analysis largely misses past chrysotile exposure because chrysotile clears quickly.

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: Retrospective, observational study of post-mortem lung samples analyzed by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), with mapping of residential addresses
• Who was studied: 77 people (58.4% male, 41.6% female) who died of malignant mesothelioma and had forensic autopsies in Pavia. The vast majority were exposed in Broni, northern Italy. Exposure was occupational in 48.0% (37) and environmental in 52.0% (40). 75 (97.4%) had pleural and 2 had peritoneal mesothelioma. People with familial exposure were excluded.
• Exposure: Asbestos from the Fibronit asbestos-cement factory in Broni, active 1932 to 1993, which used mainly a mixture of chrysotile and crocidolite, with amosite in smaller quantities. Occupational exposure meant asbestos workers, most at Fibronit. Environmental exposure meant living close to the factory, with no occupational exposure. Only fibers longer than 5 µm, thinner than 3 µm and with an aspect ratio of at least 3:1 were counted.
• Main results:
  • In all 77 subjects, the mean lung asbestos concentration was 80341 fibers per gram of dry weight (SD 241,542). Asbestos was detected in 71.4% of subjects.
  • Fibers classified as chrysotile/asbestiform antigorite were detected in 5 of 77 subjects (6.5%). SEM-EDS cannot unequivocally distinguish chrysotile from asbestiform antigorite.
  • Uncoated asbestos fiber concentrations did not differ significantly between the occupational and environmental groups, except amosite, which was higher in the occupational group. Total asbestos medians were 14,740.00 (occupational) versus 10,262.64 (environmental) fibers per gram of dry weight, p = 0.13.
  • Median amosite concentration was 9561.00 per gram of dry weight in the occupational group versus 1704.82 in the environmental group (p = 0.03).
  • Median asbestos body concentration was 17,469.00 per gram of dry weight in the occupational group versus 0.00 in the environmental group (p less than 0.0001).
  • After adjustment for age at death and sex, amosite remained significantly higher in the occupational group. Mean fiber width and asbestos body concentration were no longer significantly different between the groups.
  • Environmental cases living within 557 m of the factory (n = 10) had significantly lower asbestos body and amosite concentrations than the 37 occupational cases. Other measures did not differ.
  • For environmental cases living 557 to 926 m from the factory (n = 19), only asbestos body concentration differed significantly from the occupational cases.
  • Environmental cases living 926 m to 10 km from the factory (n = 10) showed no significant differences from the occupational cases on any measure.
  • In the 39 environmental cases within 10 km, the ratio of residence duration to distance was not significantly associated with any lung asbestos measure.
  • Distance from the factory was not significantly associated with lung asbestos content, except for asbestos body concentration (Spearman coefficient 0.39, p = 0.01 in Table 3).
• The authors' conclusion: The authors concluded that the study suggests heavy asbestos pollution affected not only the area next to the factory but the entire town of Broni and its surroundings.
• Limitations the authors state:
  • Many environmentally exposed subjects had several addresses during their lives, so the authors used the address of longest residence.
  • Asbestos bodies were counted by SEM on 0.25 g of lung rather than by light microscopy on the usual 3 to 6 g. The authors say this could underestimate asbestos body concentration.
  • Lung burden analysis largely fails to capture past chrysotile exposure because chrysotile has low biodurability and clears quickly from the lungs. Only small amounts of chrysotile/asbestiform antigorite were found, in five subjects.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Asbestos Exposure, Malignant Mesothelioma, Environmental Exposure, Scanning Electron Microscopy (SEM), Asbestos-Cement.

Related studies

• Evaluation of Deposition and Clearance of Asbestos (Detected by SEM-EDS) in Lungs of Deceased Subjects Environmentally and/or Occupationally Exposed in Broni (Pavia, Northern Italy) — S.D. Visonà, S. Capella, et al. (2021)
• Inorganic Fiber Lung Burden in Subjects with Occupational and/or Anthropogenic Environmental Asbestos Exposure in Broni (Pavia, Northern Italy): An SEM-EDS Study on Autoptic Samples — S.D. Visonà, S. Capella, et al. (2021)
• Reply to Mirabelli et al. Is Mesothelioma Unrelated to the Lung Asbestos Burden? Comment on "Visonà et al. Inorganic Fiber Lung Burden in Subjects with Occupational and/or Anthropogenic Environmental Asbestos Exposure in Broni (Pavia, Northern Italy): An SEM-EDS Study on Autoptic Samples. Int. J. Environ. Res. Public Health 2021, 18, 2053" — S.D. Visonà, S. Capella, et al. (2021)
• Survey of British pathologists' performance of mesothelioma post-mortems — R. Goldstein, P.S. Hasleton (2010)
• Malignant peritoneal mesothelioma in a boar who lived in Calabria (Italy): Wild animal as sentinel system of human health — E. Colombino, S. Capella, et al. (2019)
• Asbestos fibre burden in the lungs of patients with mesothelioma who lived near asbestos-cement factories — P.G. Barbieri, D. Mirabelli, et al. (2012)

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