Radiologic changes after cessation of exposure among chrysotile asbestos miners in Italy

Our plain-English summary of Radiologic changes after cessation of exposure among chrysotile asbestos miners in Italy, by G.F. Rubino, M. Newhouse, R. Murray, et al (Annals of the New York Academy of Sciences, 1979).

The study

• Authors: G.F. Rubino, M. Newhouse, R. Murray, G. Scansetti, G. Piolatto, G. Aresini
• Journal: Annals of the New York Academy of Sciences
• Published: 1979;330:157-61
• Cited by: 12 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. 001048).

Summary of the article

The authors noted that no published report had described whether asbestosis progresses after exposure stops. As a preliminary part of a morbidity study of chrysotile asbestos miners in Balangero, northern Italy, they examined whether radiologic changes appeared or progressed in retired workers. Of 473 men who had left employment between 1946 and 1975, 265 responded to an invitation for clinical examination, chest x-ray and lung function tests. Fifty-six were included. Each had left exposure more than 3 years earlier, had a comparable film from the end of exposure, and had no radiologic changes from other chest conditions. Pairs of films, taken on average about 12 years apart, were read side by side in chronological order by three experienced readers using the ILO/UC classification. Mean exposure was 23.4 years. At the end of exposure, 32.1% had irregular opacities of category 1/0 or higher and 19.6% had pleural changes. Of the 18 men with abnormal first films, 7 (38.9%) showed progression after an average of 8 years. Of the 38 men with normal first films, 3 (7.9%) developed opacities after an average of 14 years. All previously observed pleural thickening progressed. Duration of exposure and smoking showed no clear effect on appearance or progression. The authors suggested that individual susceptibility plays a role. They concluded that men with radiologic signs should not be permitted to work where asbestos exposure exists.

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

The study asked whether asbestosis appeared or worsened after exposure ended in retired chrysotile miners from Balangero, northern Italy. Of 473 men who left work in 1946 to 1975, 265 responded and 56 met the criteria. Three readers compared each man's end-of-exposure chest X-ray with a current one, about 12 years apart on average. At the end of exposure, 18 of the 56 (32.1%) had irregular lung opacities of ILO/UC category 1/0 or higher, and 7 of them (38.9%) progressed after an average of 8 years. Of the 38 men whose earlier films showed no irregular opacities, 3 (7.9%) developed them after an average of 14 years. All pleural thickening seen earlier had progressed. The authors found no appreciable difference between men who worked under or over 20 years, nor evidence that smoking affected appearance or progression. They suggested individual susceptibility plays a role and concluded that men showing radiologic signs should not be permitted to work where asbestos exposure exists. The results rest on about 20% of responders. Earlier films were not always available, and most were discarded for poor quality.

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: Preliminary follow-up study comparing paired chest X-rays (one from the end of exposure, one from the current survey), carried out within an ongoing morbidity study
• Who was studied: 56 retired miners from Balangero, northern Italy, selected from the 265 who responded out of 473 men who left employment between 1946 and 1975. Inclusion required more than 3 years since exposure ended, a comparable film from the end of exposure, and no X-ray changes from other chest conditions.
• Exposure: Chrysotile asbestos mining at Balangero. The mean duration of exposure was 23.4 years, and the mean age at starting work was 24.2 years.
• Main results:
  • At the end of exposure, 18 of 56 men (32.1%) had irregular opacities of ILO/UC category 1/0 or higher, and 19.6% had pleural changes. In total, 39.3% had parenchymal or pleural changes or both.
  • Among the 18 men with irregular opacities at the end of exposure, 7 (38.9%) showed progression after an average interval of 8 years. In 4 of these 7, the change was greater than one ILO/UC step.
  • Among the 38 men without irregular opacities (below category 1/0) at the end of exposure, 3 (7.9%) showed a first appearance of irregular opacities. The authors described this as about 8%, after an average interval of 14 years. Some of these 38 men had pleural changes on the earlier film.
  • The profusion of lung opacities did not exceed category 2/1 in either set of films.
  • For irregular opacities, no appreciable difference in first appearance or progression was found between men who had worked less than 20 years and those who had worked more than 20 years.
  • At the end of exposure, irregular opacities were more common in smokers (16 of 41, 39.0%) than in nonsmokers (2 of 15, 13.3%). The authors found no evidence that smoking influenced first appearance or progression.
  • All pleural thickening seen at the end of exposure had progressed, mostly in width. One new case of pleural thickening appeared, and one calcified plaque increased in size.
• The authors' conclusion: The authors suggested that individual susceptibility plays a role in both the first appearance and the progression of asbestosis. They concluded that men who show radiologic signs should not be permitted to work where asbestos exposure exists. They also concluded that a specific exposure time or accumulated dose is of little value as a criterion for ending exposure.
• Limitations the authors state:
  • The results are based on only about 20% of the retired workers who responded to the invitation.
  • Films from the end of exposure were not always available, and most of them were discarded because of poor quality.

Topics

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

Medical terms in this study, explained in our Lexicon: Chrysotile, Chest X-Ray, Pleural Thickening, Asbestos Exposure.

Related studies

• An update of cancer mortality among chrysotile asbestos miners in Balangero, northern Italy — G. Piolatto, E. Negri, et al. (1990)
• Radiographic changes in a group of chrysotile miners and millers exposed to low asbestos dust concentrations — S. Cordier, G. Theriault, et al. (1984)
• An update of cancer mortality among chrysotile asbestos miners in Balangero, northern Italy — R. Calisti, P. De Giuli, et al. (1992)
• An update of a mortality study of talc miners and millers in Italy — M. Coggiola, D. Bosio, et al. (2003)
• Asbestos in the sputum, crackles in the lungs, and radiologic changes in women exposed to asbestos — J.C. Davies, D. Kielkowski, et al. (2004)
• Mortality from cancer and other causes in the Balangero cohort of chrysotile asbestos miners — E. Pira, C. Pelucchi, et al. (2009)

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