Dynamics of the lung function in asbestos pleural disease

Our plain-English summary of Dynamics of the lung function in asbestos pleural disease, by I. Perić, D. Arar, I. Barisić, et al (Arhiv Za Higijenu Rada I Toksikologiju, 2007).

The study

• Authors: I. Perić, D. Arar, I. Barisić, I. Goić-Barisić, N. Pavlov, J. Tocilj
• Journal: Arhiv Za Higijenu Rada I Toksikologiju
• Published: 2007;58(4):407-12
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

As a rule, asbestosis is a disease of workers who are occupationally exposed to inhalation of asbestos dust, leaving permanent alterations on the lung parenchyma or pleura. In our ten-year study, we investigated 318 workers with pleural asbestosis from whom we took medical history which included occupational exposure to asbestos, radiological examinations and lung function, which is mandatory for the diagnosis and the follow up of the disease. We analysed functional parameters such as forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) and intermediate forced expiratory flow at 25% to 75% (FEF25%-75%). In addition, we investigated the predicted values of functional parameters according to smoking and non-smoking habits. We found a significant reduction in vital capacity, particularly in smokers after 25 years of exposure to asbestos. During the first 15 years, values of vital capacity on the group basis remained inside the 80% of the normal values and were not significant for assessing the dynamics of the lung function. To better assess the effects of occupational asbestos exposure, it is necessary to interpret lung function data not only on the group basis, but also for each subject individually.

In plain English

The authors studied lung function in 318 Croatian workers with pleural asbestosis who had worked at least five years at an asbestos-cement factory, an asbestos products factory or a shipyard. Their asbestos exposure lasted 5 to 30 years, averaging 19.6 years. The article does not say which fiber types these workers were exposed to. Spirometry results were compared with predicted values by years of exposure. Adjusted for age and sex, forced vital capacity (FVC) fell from 99% of predicted to 90% after ten years and, significantly, to 79% after over 20 years. FEV1 fell from 105% to 97%, then significantly to 89%. Mid-expiratory flow fell to 90% and returned to 100%, not a statistically significant change. In non-smokers, FVC fell from 110% to 90% after ten years and to 80% after 20 years. In smokers, FVC fell below 80% after 20 years and, as printed, to 50% after 35 years. The authors concluded that smoking contributed more than pleural asbestosis to the fall in vital capacity, and that each worker should be followed individually. Some figures in the article are inconsistent.

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: Study of lung function (spirometry) in workers with diagnosed pleural asbestosis, analysed by duration of asbestos exposure and by smoking habit; described by the authors as a ten-year study
• Who was studied: 318 workers in Croatia with verified pleural asbestosis and at least five years of work at: the asbestos-cement products factory Salonit in Vranjic (126, 40%), the asbestos products factory Plobest in Ploče (139, 43%), and the shipbuilder Brodogradevna industrija Split (BIS, 53, 17%). There were 243 men (average age 53) and 76 women (average age 49). By smoking habit there were 170 smokers, 110 non-smokers and 38 ex-smokers.
• Exposure: Occupational inhalation of asbestos dust in asbestos-cement and asbestos product manufacturing and shipbuilding, lasting 5 to 30 years (average 19.6 years). The article names chrysotile, crocidolite and other amphiboles only in its background and does not say which fiber types the studied workers encountered. Smoking was also analysed (smokers had at least five cigarettes a day, on average 20 to 30).
• Main results:
  • All workers, adjusted for age and sex: FVC fell from 99% to 90% of predicted after the first ten years of exposure, and fell to 79% with exposure over 20 years (t=5.86; p less than 0.001), which was statistically significant
  • All workers: FEV1 fell from 105% to 97% of predicted after the first ten years of exposure, and fell significantly to 89% in the next ten years (t=3.40; p less than 0.01)
  • All workers: forced expiratory flow (FEF25-75%) fell from 100% to 90% after the first ten years, then returned to 100% of predicted in the next ten years (t=2.01; p=0.13)
  • At the beginning of exposure, median FVC was 110% of predicted in non-smokers and 100% in smokers
  • Non-smokers: FVC fell to 90% of predicted after the first ten years (t=9.12; p less than 0.001), stayed unchanged until after 20 years of exposure, then fell to 80% (t=9.63; p less than 0.0001)
  • Smokers: FVC did not differ significantly from predicted after the first ten years (t=0.29; p=0.74), and fell to under 80% after 20 years (t=5.80; p less than 0.001)
  • Smokers: after 35 years of exposure, FVC was reported to have fallen to 50% of predicted (t=12.06; p less than 0.000001)
• The authors' conclusion: The authors concluded that the fall in vital capacity was more marked in smokers than in non-smokers, and that smoking contributed more to the decrease in vital capacity than pleural asbestosis. They also concluded that lung function should be interpreted for each worker individually, not only by group.
• Limitations the authors state:
  • The authors noted that group-based analysis can miss falls in lung function in a particular person, because spirometric values in young people may vary 20% to 30% above predicted. In their view, only individual follow-up over a longer period could show a significant fall for a specific person.

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos-Related Pleural Disease, Parenchyma, Pleura, Occupational Exposure, FEV1, Habit, Asbestos Exposure.

Related studies

• Abnormal lung function associated with asbestos disease of the pleura, the lung, and both: a comparative analysis — K.H. Kilburn, R.H. Warshaw (1991)
• Lung function and chest radiograph abnormalities among construction insulators — S.M. Kennedy, S. Vedal, et al. (1991)
• Maximal expiratory flow volume curves in workers exposed to asbestos — R. Rodriguez-Roisin, J.E. Merchant, et al. (1980)
• Review of the Kilburn and Warshaw Chest article--airways obstruction from asbestos exposure — R.N. Jones, H.W. Glindmeyer, et al. (1995)
• Cigarette smoke potentiates asbestos-induced airflow abnormalities — J.L. Wright, V. Tron, et al. (1988)
• Pulmonary function in asbestosis and asbestos-related pleural disease — A. Miller (1993)

Browse more research in Arhiv Za Higijenu Rada I Toksikologiju, or return to medical research.