Environmental asbestotic pleural plaques in northeast Corsica: correlations with airborne and pleural mineralogic analysis

Our plain-English summary of Environmental asbestotic pleural plaques in northeast Corsica: correlations with airborne and pleural mineralogic analysis, by F. Rey, C. Boutin, J.R. Viallat, et al (Environmental Health Perspectives, 1994).

The study

• Authors: F. Rey, C. Boutin, J.R. Viallat, J. Steinbauer, P. Alessandroni, P. Jutisz, D. Di Giambattista, M.A. Billon-Galland, P. Hereng, P. Dumortier
• Journal: Environmental Health Perspectives
• Published: 1994;102 Suppl 5(Suppl 5):251-2
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

We report a prevalence study of environmental pleural plaques in subjects over 50 years old from the northeastern Corsican village of Murato, built on asbestos surface deposits. The percentage of plaques was 41%, versus 7.5% in the control village of Vezzani. Although surface deposits contain both chrysotile and tremolite, airborne pollution and asbestos lung burden of exposed inhabitants consist essentially of tremolite as assessed by transmission electron microscopy (TEM). However, TEM analysis of the parietal pleura of three animals bred in exposed areas showed a predominance of short fibers of chrysotile. The respective roles of tremolite and chrysotile in inducing pleural plaques in Corsica should thus be considered.

In plain English

This prevalence study compared two villages in northeastern Corsica, where asbestos outcrops contain chrysotile and tremolite. The authors X-rayed all inhabitants over 50 who were born in the villages and lived there more than 6 months a year, excluding people with occupational asbestos exposure or past pleural disease. Bilateral pleural plaques were found in 34 of 83 people (41%) in Murato, the exposed village, and in 8 of 108 (7.4%) in Vezzani, the control village. The relative risk was 5.53. In Murato, 64.7% of men and 24.5% of women had plaques. The authors suggested that the men's occupations had added to their exposure, while plaques in a quarter of the women suggested non-occupational exposure. Airborne tremolite was over 100 times higher in Murato than in Vezzani. Chrysotile was four times higher, but that difference was not statistically significant. In the pleura of one dog and two goats from exposed areas, fibers were short and mostly chrysotile, with tremolite making up 5 to 9%. The authors concluded their data could not show whether tremolite or chrysotile alone caused the pleural disease seen in Corsica.

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: Prevalence (cross-sectional) study comparing an exposed and a control village by chest X-ray, with airborne fiber measurements by transmission electron microscopy (TEM) and TEM analysis of the pleura of three domestic animals
• Who was studied: Inhabitants over 50 years old, born in and living more than 6 months a year in two villages of northeast Corsica. Murato (exposed): 83 people (34 men, 49 women, mean age 68 plus or minus 1 year). Vezzani (control): 108 people (48 men, 60 women, mean age 66 plus or minus 1 year). People with occupational asbestos exposure or a history of pleural pathology were excluded. Also studied: one dog and two goats bred in exposed areas. Study dates not given.
• Exposure: Environmental (non-occupational) exposure to asbestos from surface deposits containing chrysotile and tremolite. Murato is described as exposed to asbestos and Vezzani as not exposed. Airborne chrysotile and tremolite were measured by TEM.
• Main results:
  • Pleural plaques were found in 34 subjects (41%) in Murato and in 8 subjects (7.4%) in the control village of Vezzani.
  • For Murato compared with Vezzani: chi-square 30.81, p printed as "< 0.000", odds ratio 8.67, relative risk 5.53.
  • In Murato, 22 of the 34 subjects with plaques were male and 12 were female: 64.7% of males (22 of 34) and 24.5% of females (12 of 49) had plaques. In Vezzani, 5 of 48 males (10.4%) and 3 of 60 females (5%) had plaques (Table 1).
  • In Murato, the prevalence of pleural plaques rose significantly with age, and more than 60% of inhabitants over 70 had radiologically visible bilateral pleural plaques.
  • Airborne chrysotile was at low levels in both villages. It was four times higher in Murato than in Vezzani, but the difference was not statistically significant.
  • Airborne tremolite concentrations were over 100 times higher in Murato than in Vezzani, with a mean concentration of 39 ng/m3 in Murato.
  • In the parietal pleura of the three animals (one dog, two goats), the mean fiber count was 46 plus or minus 27 million fibers per gram of dried tissue.
  • The animal pleural fibers were short, with mean lengths from 0.9 micrometres (one goat) to 1.2 micrometres (dog). Tremolite made up only 5 to 9% of the fibers, and the rest were chrysotile.
• The authors' conclusion: The authors concluded that, because both pleural plaques and mesothelioma develop from the parietal pleura, neither earlier data nor the present data allow them to deduce whether tremolite or chrysotile alone is responsible for the environmentally induced pleural diseases in Corsica.
• Limitations the authors state:
  • The authors described the animal pleura analysis (three animals) as a preliminary study.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Plaques, Chrysotile, Tremolite, Transmission Electron Microscopy (TEM), Parietal Pleura.

Related studies

• Pleural effects of environmental asbestos pollution in Corsica — J.R. Viallat, C. Boutin, et al. (1991)
• Environmental airborne tremolite asbestos pollution and pleural plaques in Afghanistan — C. Voisin, I. Marin, et al. (1994)
• Black spots concentrate oncogenic asbestos fibers in the parietal pleura. Thoracoscopic and mineralogic study — C. Boutin, P. Dumortier, et al. (1996)
• Environmental mesothelioma associated with tremolite asbestos: lessons from the experiences of Turkey, Greece, Corsica, New Caledonia and Cyprus — S.H. Constantopoulos (2008)
• Chrysotile and tremolite asbestos fibres in the lungs and parietal pleura of Corsican goats — P. Dumortier, F. Rey, et al. (2002)
• Introduction: INSERM-IARC-CNRS workshop on biopersistence of respirable synthetic fibers and minerals — J. Bignon, R. Saracci, et al. (1994)

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