Pleural plaques in the general population

Our plain-English summary of Pleural plaques in the general population, by G. Hillerdal (Annals of the New York Academy of Sciences, 1991).

The study

• Author: G. Hillerdal
• Journal: Annals of the New York Academy of Sciences
• Published: 1991;643:430-7
• 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. 004488).

Summary of the article

The author used pleural plaques to measure the impact of asbestos on the general population of Uppsala county, Sweden, which had a population of 250,782 in 1985. A general health survey invited all inhabitants aged 15 and over every second or third year until June 1985 and included a small-size chest X-ray. The study included all persons found from 1970 to June 1985 with plaques meeting strict radiological criteria: bilateral, at least 5 mm thick and/or calcified, well demarcated, and progressing over 5 years. Referred patients were also included. All were recalled for examination and an exposure history. There were 1,596 men and 79 women, and 1,349 (84.6 percent) were found in the survey. By 1985, plaques were present in 2.7 percent of males over 40. Of the men, 88.4 percent had occupational asbestos exposure, most often in building and construction, 0.8 percent had nonoccupational exposure, and 10.8 percent denied exposure. Of the women, 13.9 percent had occupational exposure, 17.7 percent had mostly domestic exposure, and 68.4 percent denied exposure. Mean latency in 1,096 men was 33.2 years. Finnish-born persons made up 49.4 percent of the women. Finnish men denied exposure more often than Swedish men (28.2 versus 9.5 percent). The author concluded that plaques in men usually reflect occupational exposure, whereas in women exposure is often not found.

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 study described 1,596 men and 79 women in the county of Uppsala, Sweden, whose pleural plaques met strict X-ray criteria between January 1, 1970 and June 30, 1985. Most were found in a general health survey with chest X-rays. Referred patients were included only if they had no signs of malignant tumor or serious lung disease. By 1985, plaques had been found in at least 2.7 percent of men aged 40 or older. The author noted the true figure is higher, because not all cases are discovered and the strict criteria leave out many plaques. Exposure information was missing for nine men. Of the others, 1,403 (88.4 percent) reported work exposure, 13 (0.8 percent) reported non-work exposure, and 171 (10.8 percent) denied any exposure. Among the women, 54 (68.4 percent) denied all exposure. Finnish-born men denied exposure more often than Swedish-born men (28.2 versus 9.5 percent). In 1,096 men, the average time from first exposure to plaques was 33.2 years. The author concluded that plaques indicate earlier asbestos exposure and that people with them are at risk of other asbestos-related diseases.

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: Descriptive study of persons with pleural plaques meeting strict radiological criteria. Most were found in a county-wide general health survey with chest X-rays. Referred or clinic patients were added if they had no signs of malignant tumor or serious lung disease. Exposure was taken from interviews at repeated check-ups.
• Who was studied: 1,596 men and 79 women (1,675 persons) with bilateral pleural plaques in the county of Uppsala, Sweden, found from January 1, 1970 to June 30, 1985. Of these, 1,349 (84.6 percent) were found in the general health survey.
• Exposure: Occupational and nonoccupational exposure to asbestos (domestic exposure, or building or insulating homes), taken from the patients' histories. The article does not name fiber types.
• Main results:
  • The occurrence of pleural plaques rose steadily and by 1985 reached a minimum of 2.7 percent among males 40 years or older in the county. The author states the true incidence is higher, since not all cases are discovered.
  • Among the men with plaques, 1,403 (88.4 percent) had occupational asbestos exposure, 13 (0.8 percent) had nonoccupational exposure, and 171 (10.8 percent) denied any exposure. These percentages are of the men with exposure information. Information was missing for nine men, who had declined to come to the check-up examination.
  • 76 persons denied any asbestos exposure at their first visit but confirmed such exposure at later visits.
  • Among occupationally exposed men, 51.6 percent had been exposed in building and construction and 38.5 percent in industries of other kinds.
  • In 1,096 men, the latency time from first asbestos exposure to the attack year of plaques was 33.2 years (1 SD = 9.2 years).
  • Among the 79 women with plaques, 11 (13.9 percent) had occupational exposure, 14 (17.7 percent) had nonoccupational exposure (mostly domestic), and 54 (68.4 percent) denied all exposure.
  • 111 men (7.0 percent) and 39 women (49.4 percent) with plaques were born in Finland.
  • Any exposure to asbestos was denied by 9.5 percent of Swedish-born men and 28.2 percent of Finnish-born men (p less than 0.0001). For women, the figures were 56.4 (Swedes) and 79.5 (Finns).
  • The author estimated that about 3 to 4 percent of the male population in a relatively slightly industrialized county such as Uppsala will have pleural plaques.
• The authors' conclusion: The author concluded that pleural plaques can be seen as an indicator of earlier asbestos exposure, and that people with plaques are therefore at risk for other asbestos-related diseases.
• Limitations the authors state:
  • The strict definition of plaques leaves many plaques out of the study, so the consequences of asbestos exposure will be underrated.
  • The true occurrence is higher than reported because not all cases are discovered.
  • Plaques were underdiagnosed especially in the first five years, so the year of discovery often differed from the year the plaques first appeared.
  • When no other information was available, the first year of work in the exposing occupation was used as the first year of exposure. The author notes this might not always be true, which could affect the latency estimate.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Plaques, Chest X-Ray, Bilateral, Exposure History, Asbestos Exposure, Occupational Exposure, Latency.

Related studies

• Diachronic study of pleural plaques in rural population with environmental exposure to asbestos — L. Sichletidis, D. Chloros, et al. (2006)
• Prevalence of pleural calcification in persons exposed to asbestos dust, and in the general population in the same district — M. Navrátil, F. Trippé (1972)
• Asbestos fibers and pleural plaques in a general autopsy population — A. Churg (1982)
• Modelling prevalence and incidence of fibrosis and pleural plaques in asbestos-exposed populations for screening and follow-up: a cross-sectional study — C. Paris, A. Martin, et al. (2008)
• Pleural plaques and exposure to mineral fibres in a male urban necropsy population — A. Karjalainen, P.J. Karhunen, et al. (1994)
• Chrysotile biopersistence in the lungs of persons in the general population and exposed workers — A.M. Langer, R.P. Nolan (1994)

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