Pleural effects of environmental asbestos pollution in Corsica

Our plain-English summary of Pleural effects of environmental asbestos pollution in Corsica, by J.R. Viallat, C. Boutin, J. Steinbauer, et al (Annals of the New York Academy of Sciences, 1991).

The study

• Authors: J.R. Viallat, C. Boutin, J. Steinbauer, A. Gaudichet, G. Dufour
• Journal: Annals of the New York Academy of Sciences
• Published: 1991;643:438-43
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 004935).

Summary of the article

This report described a series of surveys of pleural disease and environmental asbestos in Corsica. Outcrops containing chrysotile and tremolite occur in the island's northeastern area. The surveys followed a 1978 finding of bilateral pleural plaques in 3.8% of control subjects who were not occupationally exposed to asbestos. At a hospital in central Corsica, two experts who did not know the patients' birthplace read chest radiographs of 1,851 patients over 50 years old who were born and living in Corsica. After exclusions, bilateral plaques were found in 3.7% of patients born in the northeast and 1.1% of those born in the northwest (p < 0.05; relative risk 3.3). In 1982, 30 of 92 people over 50 (33%) in exposed villages, with no known occupational exposure, had bilateral plaques. A 1988 survey found plaques in 41% of inhabitants over 50 in Murato, an exposed village, compared with 6% in Vezzani, an unexposed village. Air samples from eight villages were analysed by transmission electron microscopy. Mean tremolite concentrations were 24 ng/m3 in exposed northeastern villages and 0.2 ng/m3 in control villages (p < 0.05). Mean chrysotile concentrations were 15.2 and 0.5 ng/m3, a difference that was not statistically significant. Since 1978 the authors had recorded eight patients with malignant mesothelioma, which they attributed to childhood environmental exposure. Lung mineral analyses showed elevated tremolite and variable chrysotile. The authors concluded that an elevated tremolite lung burden is a marker of environmental exposure in Corsica. They also stated that their data were not sufficient to show that either mineral alone was responsible for the pleural disease.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This paper reported a series of surveys on pleural effects of environmental asbestos in Corsica, whose northeast has outcrops of both chrysotile and tremolite. Among hospital patients over 50 born and living in Corsica, chest radiographs showed bilateral pleural plaques in 3.7 percent of those born in the northeast and 1.1 percent of those born in the northwest (p less than 0.05), a relative risk index of 3.3. In 1988, 34 of 83 people X-rayed in the exposed village of Murato (41 percent) had bilateral plaques, against 8 of 129 (6.2 percent) in Vezzani, a village classed as unexposed. Air sampling found mean tremolite of 24 ng/m3 in exposed villages versus 0.2 ng/m3 in control villages (p less than 0.05). The chrysotile difference was not statistically significant. The authors also recorded eight malignant mesothelioma patients they attributed to childhood environmental exposure. In four of them, lung analysis showed elevated tremolite. The authors concluded that a raised tremolite lung burden marked environmental exposure in Corsica, but that their data were not sufficient to say either mineral alone caused the pleural pathology.

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: Series of surveys: a review of hospital chest radiographs, radiographic surveys in villages (1982 and 1988), an air monitoring study using transmission electron microscopy, and a case series of mesothelioma patients with lung mineral analysis
• Who was studied: 1,851 patients older than 50, born and living in Corsica, hospitalized at Tattone hospital within the last two decades (1,457 born in the northeast, 264 in the northwest, and a sample of 130 born in southern Corsica). Also village residents over 50 X-rayed in 1982 (92 people) and 1988 (Murato and Vezzani), air samples from eight villages, and eight mesothelioma patients.
• Exposure: Non-occupational environmental exposure to chrysotile and tremolite asbestos from natural outcrops in schistous areas of northeastern Corsica, judged by birthplace or village of residence
• Main results:
  • After exclusions, 56 hospital patients had bilateral pleural plaques: 53 born in northeastern Corsica and 3 in the northwestern area. The frequency of plaques was 3.7 percent for those born in the northeast and 1.1 percent for those born in the northwest (p less than 0.05), with a relative risk index of 3.3.
  • The northeastern patients with bilateral plaques were all born in villages located on asbestos outcrops. 26 percent of them were female.
  • In 1982, 30 of 92 people over 50 born in exposed villages and without known occupational asbestos exposure (33.0 percent, about one-third) had bilateral plaques
  • In 1988, 41 percent of those X-rayed in Murato (34 of 83) had bilateral pleural plaques, compared with 6 percent in Vezzani (8 of 129, given as 6.2% in the table)
  • At Murato, people with plaques were significantly older than those without (p less than 0.01). 35 percent of those with plaques were female, which the authors called strongly suggestive of nonoccupational exposure.
  • Mean airborne chrysotile was 0.5 ng/m3 in control villages and 15.2 ng/m3 in exposed villages. This difference was not statistically significant.
  • Mean airborne tremolite differed significantly (p less than 0.05) between control villages (0.2 ng/m3) and exposed villages (24 ng/m3). Tremolite fibers were significantly longer than chrysotile fibers.
  • In exposed villages, airborne asbestos ranged from undetectable to 200 ng/m3
  • Since 1978, the authors recorded eight patients with malignant mesothelioma that they described as caused by childhood environmental exposure to asbestos in Corsica
  • In four of the mesothelioma patients, lung mineral analysis showed variable amounts of chrysotile but elevated levels of tremolite
  • The authors reviewed 58 lung specimens (25 control subjects, 25 patients with occupational exposure, 8 Corsicans with environmental exposure). In their experience, a tremolite lung burden was highly specific for environmental exposure in Corsica.
• The authors' conclusion: The authors concluded that an elevated tremolite lung burden is a marker of environmental exposure to both chrysotile and tremolite in Corsica, since the two minerals occur together. They also concluded that the relationship between bilateral plaques and birthplace near asbestos deposits was supported by their X-ray results.
• Limitations the authors state:
  • In the 1982 village survey, only 92 people agreed to be X-rayed, which the authors put down to a lack of mainly psychological preparation
  • No epidemiological survey of asbestos-related cancer was in progress in Corsica. The mesothelioma cases came from patients referred to the authors' department.
  • Tarring of roads in exposed villages has probably considerably lowered asbestos pollution, so the measured airborne levels may not reflect past exposure
  • The authors stated their data were not sufficient to conclude that either chrysotile or tremolite alone was responsible for the pleural pathology

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma, Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Chrysotile, Tremolite, Bilateral, Pleural Plaques, Chest X-Ray, Relative Risk, Occupational Exposure, Transmission Electron Microscopy (TEM).

Related studies

• Environmental asbestotic pleural plaques in northeast Corsica: correlations with airborne and pleural mineralogic analysis — F. Rey, C. Boutin, et al. (1994)
• Environmental airborne tremolite asbestos pollution and pleural plaques in Afghanistan — C. Voisin, I. Marin, et al. (1994)
• Environmental mesothelioma associated with tremolite asbestos: lessons from the experiences of Turkey, Greece, Corsica, New Caledonia and Cyprus — S.H. Constantopoulos (2008)
• Nonmalignant pleural lesions due to environmental exposure to asbestos: a field-based, cross-sectional study — M. Metintas, S. Metintas, et al. (2005)
• Environmental asbestos pollution -- situation in Poland — N. Szeszenia-Dąbrowska, W. Sobala, et al. (2012)
• Assessment of both environmental cytotoxicity and trace metal pollution using Populus simonii Carr. as a bioindicator — V. Sluchyk, I. Sluchyk, et al. (2014)

Browse more research in Annals of the New York Academy of Sciences, or return to medical research.