Parenchymal and pleural fibrosis in construction workers

Our plain-English summary of Parenchymal and pleural fibrosis in construction workers, by P. Oksa, H. Koskinen, J.P. Rinne, et al (American Journal of Industrial Medicine, 1992).

The study

• Authors: P. Oksa, H. Koskinen, J.P. Rinne, A. Zitting, P. Roto, M.S. Huuskonen
• Journal: American Journal of Industrial Medicine
• Published: 1992;21(4):561-7
• Cited by: 17 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. 004907).

Abstract

Exposure to mineral dust was studied among construction workers (N = 437) with the aid of a questionnaire and a chest X-ray examination of the lungs. The results of the questionnaire showed that 81% of the construction workers had been exposed to asbestos. Exposure had occurred in all of the occupational groups studied. Pleural plaques and/or lung fibrosis (ILO greater than or equal to 1/1) were found in 26% of the examined workers; the prevalence varied from 18 to 40% among the various occupational groups. Comparison with a representative sample of the Finnish male population from another investigation indicates that the frequency of lung fibrosis (ILO greater than or equal to 1/1) is at least two times higher among the examined construction workers than among the general population. It seems likely that exposure to asbestos dust can be considered an etiological factor for an appreciable number of the X-ray findings.

In plain English

This 1987-1988 screening study examined construction workers near Tampere, Finland. Of 993 eligible union members (members since at least 1967), 437 (44%) answered a questionnaire on asbestos and quartz dust exposure and had a chest X-ray. Eighty-one percent reported asbestos exposure, averaging 3.7 years counted as whole workdays, and 89% reported silica exposure. Lung fibrosis at ILO 1/1 or higher was seen in 70 workers (16%), and definite bilateral pleural plaques in 61 (14%). In all, 26% had either or both, ranging from 18% to 40% across trades. Nodular shadows typical of silicosis appeared in only two workers. Findings were associated with reported asbestos exposure and longer employment, with only a slight trend for quartz. Age-adjusted, the fibrosis rate was 8.8%, which the authors called twice the 4.4% in a separate study of Finnish men. The authors concluded that asbestos exposure was likely a causal factor in an appreciable number of the X-ray findings. The authors could not assess non-participants. They noted that workers with respiratory symptoms may have joined more readily, so exposure and X-ray changes may have been rarer among non-participants.

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: Cross-sectional screening study using a questionnaire, an interview and chest X-rays
• Who was studied: Members of three sections of the local construction workers' union around Tampere, Finland, who had been members since 1967, working or retired. Of 993 eligible, 437 (44%) took part, and they were examined in 1987-1988. Half were retired, 93% were men, and the mean age was 59 years (range 35-85). The trades included pipefitters, pipe insulators, carpenters, laborers, cement workers, concrete reinforcement workers, bitumen insulators and others.
• Exposure: Self-reported direct and indirect asbestos exposure (fiber type not specified) and quartz (silica) dust exposure in construction work. Exposure was estimated in whole workdays from the questionnaire and a nurse interview.
• Main results:
  • 81% of the 437 workers reported asbestos exposure. The average duration was 3.7 years, counted as whole workdays.
  • 89% of the workers reported silica dust exposure, with an average duration of 4.9 years
  • Lung fibrosis at ILO 1/1 or higher was found in 70 of the 437 workers (16%). In 9 of them (2%), it was ILO 2/1 or higher.
  • Small lung opacities were almost always irregular. Only two workers (0.8%) had partly or completely nodular opacities, the type typical of silicosis.
  • Definite bilateral pleural plaques were found in 61 workers (14%). Unilateral or suspected plaques were found in 112 workers (26%).
  • Pleural plaques and/or lung fibrosis (ILO 1/1 or higher) were found in 26% of all workers, ranging from 18% to 40% across occupational groups
  • The highest combined prevalence was in pipe insulators (40%, which is 2 of the 5 pipe insulators in the table) and carpenters (32%)
  • Definite diffuse pleural thickening and pleural adhesions, indicating changes of the visceral pleura, were found in 38 workers (9%)
  • X-ray changes were associated with reported asbestos exposure, with only a slight trend for quartz. In Table III, the 113 workers with fibrosis of ILO 1/1 or higher and/or definite plaques reported 59 months of asbestos exposure. The 135 workers with no findings reported 32 months (p = 0.02).
  • Findings tended to be more common with longer employment in construction. The trend was clearer when lung and pleural findings were considered together.
  • Small opacities of ILO 1/1 or higher were found in 14 of 123 non-smokers (11%), 32 of 218 ex-smokers (15%) and 23 of 95 current smokers (24%). Pleural plaques were not related to smoking.
  • The crude rate of fibrosis at ILO 1/1 or higher was 16%. Age-adjusted to the general Finnish male population, it was 8.8%. The authors described this as twice the 4.4% found in a separate study of a representative sample of 3,280 Finnish men. The 4.4% comes from that other study, not this one.
• The authors' conclusion: The authors concluded that asbestos dust exposure was likely a causal (etiological) factor in an appreciable number of the X-ray findings
• Limitations the authors state:
  • Only 44% of those invited took part, and non-participants could not be evaluated. People with respiratory symptoms may have been more likely to take part, so exposure and X-ray changes may have been less common among non-participants.
  • The ILO classification was not used in detail, so the results cannot be compared directly with studies that used a different classification
  • Smoking may have modified the fibrosis-causing effect of asbestos

Topics

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

Medical terms in this study, explained in our Lexicon: Fibrosis, Chest X-Ray, Pleural Plaques.

Related studies

• Asbestosis: interstitial pulmonary fibrosis and pleural fibrosis in a cohort of asbestos insulation workers: influence of cigarette smoking — R. Lilis, I.J. Selikoff, et al. (1986)
• Radiographic abnormalities in asbestos insulators: effects of duration from onset of exposure and smoking. Relationships of dyspnea with parenchymal and pleural fibrosis — R. Lilis, A. Miller, et al. (1991)
• Asbestos-related pleural and lung fibrosis in patients with retroperitoneal fibrosis — T. Uibu, R. Järvenpää, et al. (2008)
• Development of radiological and clinical evidence of parenchymal fibrosis in men with non-malignant asbestos-related pleural lesions — G.H. McMillan, C.E. Rossiter (1982)
• Season of birth and lung fibrosis among workers exposed to asbestos — T. Hannu, M.S. Jaakkola, et al. (2007)
• Diffusing capacity and forced vital capacity in 5,003 asbestos-exposed workers: relationships to interstitial fibrosis (ILO profusion score) and pleural thickening — A. Miller, R. Warshaw, et al. (2013)

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