Pleural Plaques And Lung Asbestos Bodies In The General Population: An Autoptical And Clinical-Radiological Survey

Our plain-English summary of Pleural Plaques And Lung Asbestos Bodies In The General Population: An Autoptical And Clinical-Radiological Survey, by G.F. Rubino, G. Scansetti, G. Piolatto, et al (1980).

The study

• Authors: G.F. Rubino, G. Scansetti, G. Piolatto, E. Pira, F. Mollo, A. Andrion, A. Colombo, L. Bertasso
• Published: Biological Effects Of Mineral Fibres (J.C. Wagner, Editor), Lyon: Iarc Scientific Publications, Volume 30, Pp. 545-551 (1980)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library, J-M no. 002185. The article is still under copyright, so we describe it here rather than post it.

In plain English

This was a preliminary report of an autopsy survey at Turin University, Italy. Of 862 consecutive autopsies done from November 1977 through March 1979, the authors studied 218 men who had chest X-rays and complete residence and work histories. A physician interviewed relatives about past jobs. Asbestos exposure was rated possible for 30 men and probable or definite for 14. Fiber types were not named. Pleural plaques were found in 67 of the 218 men (about 30%), and the proportion rose with age at death. Men with plaques more often had a history of asbestos exposure (overall odds ratio 3.74). Seven of the eight men whose plaques had a total surface area exceeding 100 square centimetres had definite exposure. Asbestos bodies in the lungs were also associated with plaques (odds ratio 1.95), but this link was not statistically significant once exposed men were excluded. Chest X-rays showed plaques in 7 of those 8 men, but in only 20 of 59 men with smaller plaques, and in 30 of 151 men without plaques. The authors concluded that the findings confirmed the link between plaques and asbestos exposure. They questioned asbestos bodies as a marker of exposure.

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 report of an autopsy (necropsy) survey of consecutive cases, with comparison to work histories and chest X-ray findings
• Who was studied: 218 men out of 862 consecutive autopsies at Turin University's Institute of Pathology (November 1977 to March 1979). These were the cases with chest films and complete residence and work histories: 67 with pleural plaques and 151 without, the latter used as controls.
• Exposure: History of asbestos exposure, taken from interviews with relatives and rated by three occupational physicians as possible (30 men), probable or definite (14 men). Lung asbestos (ferruginous) bodies were also counted. No fiber types were specified, and no exposure to fibres other than asbestos was found.
• Main results:
  • Pleural plaques were found at autopsy in 67 of 218 men (proportion 0.307). Prevalence was related to age: 3 of 43 men up to age 40, 4 of 26 aged 41-50, 22 of 57 aged 51-60, and 38 of 92 over 60.
  • Eight men had plaques with a total (global) surface over 100 square centimetres (Grade II), ranging up to 600. All of them were over 50 years old.
  • The proportion with possible, probable or definite asbestos exposure was 0.132 among the 151 men without plaques, 0.271 among the 59 with Grade I plaques, and 1.000 among the 8 with Grade II plaques. The overall odds ratio for any plaques versus none was 3.74 (chi-square for association 13.18, P less than 0.001).
  • Of the eight men with Grade II plaques, seven had definite and one had possible asbestos exposure. Only one of them showed evidence of fibrosis of the lung tissue.
  • The proportion with asbestos bodies in the lungs was 0.318 among men without plaques, 0.492 with Grade I plaques, and 0.875 with Grade II plaques. The overall odds ratio was 1.95 (P less than 0.05), and it was 2.62 when only men with more than 10 ferruginous bodies in the smear were counted.
  • When men with histories of asbestos exposure were excluded, the difference in the presence of asbestos bodies between men with and without plaques was not statistically significant.
  • Lung smears showed no ferruginous bodies in six men with probable or definite asbestos exposure.
  • Chest X-rays showed pleural changes in 7 of 8 men with Grade II plaques and in 20 of 59 with Grade I plaques. They also showed changes in 30 of 151 men with no plaques at autopsy (false positives).
• The authors' conclusion: The authors concluded that the results confirm the relationship between pleural plaques and asbestos exposure. They expressed reservations about ferruginous bodies as an indicator of asbestos exposure. They stated that population studies based on X-ray films only may seriously underestimate plaque prevalence and, to a lesser extent, give false positive results.
• Limitations the authors state:
  • The radiological examinations were not always carried out under optimal conditions, and posteroanterior films have a limited ability to detect plaques located toward the front or back of the chest.
  • Because few men had Grade II plaques, the statistical analysis compared plaques of any size with no plaques.
  • This was a preliminary report. An examination of place of residence, to assess neighbourhood or other environmental sources of exposure, was still in progress.

Topics

Medical terms in this study, explained in our Lexicon: Pleural Plaques, Asbestos Bodies, Autopsy, Chest X-Ray, Asbestos Exposure, Odds Ratio.

Browse return to medical research.