High prevalence of reversible airway obstruction in asbestos-exposed workers

Our plain-English summary of High prevalence of reversible airway obstruction in asbestos-exposed workers, by S. Delpierre, M.J. Delvolgo-Gori, M. Faucher, et al (Archives of Environmental Health, 2002).

The study

• Authors: S. Delpierre, M.J. Delvolgo-Gori, M. Faucher, Y. Jammes
• Journal: Archives of Environmental Health
• Published: 2002;57(5):441-5
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

In this retrospective study of 97 male workers exposed to asbestos for 2-50 yr, data were collected on chest x-ray findings and lung function, including lung volumes, forced expiratory flow rates (i.e., forced expiratory volume in 1 sec [FEV1.0], forced expiratory flow measured between 25% and 75% of forced vital capacity [FEF(25-75%)]), airway resistance (R(aw)), carbon monoxide (CO)-diffusing capacity, and the existence of airway obstruction reversible by a beta-adrenergic agonist (RAO). The authors performed multiple-regression analyses to correlate the variations in lung function data with age, smoking habits, duration of asbestos exposure, and time since last exposure. Occupational activities of subjects that might induce specific lung abnormalities were also considered. No significant decrease was seen in lung volumes or CO-diffusing capacity; however, a decrease in FEV1.0 and an increase in R(aw) were measured in 65% of the subjects, and an isolated decrease in FEF(25-75%) occurred in only 18%. There was no difference in lung-function data between subjects who had chest x-ray signs of abnormalities (n = 59) and those who did not (n = 38). A significant relationship was found between the decrease in FEV1.0 and age; however, no correlation was noted between altered lung function and cigarette smoking, duration of asbestos exposure, or time since last exposure. RAO prevalence was higher (34%) than previously reported (9%) in subjects with chronic obstructive pulmonary disease (COPD) who were not exposed to asbestos or outdoor pollution. The RAO prevalence in asbestos-exposed workers was nearly the same as that measured in COPD subjects who lived downtown and who were exposed to outdoor pollution (36%). The high RAO prevalence in asbestos-exposed workers was found in 43% of subjects who were exposed only to asbestos, and in 33% of subjects who were also exposed to air pollution due to their occupational activities. It is hoped that the observations in this study will encourage practitioners to check for RAO in asbestos workers who use inhaled bronchodilators.

In plain English

This retrospective study from a Marseille, France, lung-function laboratory reviewed tests on 97 men exposed to asbestos for 2 to 50 years: 45 shipyard workers, 12 asbestos-cement builders and 40 insulation installers. Fifty-nine had pleural plaques or thickening on x-ray; 38 had normal x-rays. Lung volumes and carbon monoxide diffusing capacity did not differ significantly from predicted. Reduced airflow (FEV1 and FEV1/VC) affected 63 of 97 men (65%); airway resistance was high in 46 of 86 (53%). Lung function did not differ significantly by x-ray findings. Lower FEV1 was related to age, not smoking, exposure duration or time since exposure. Of 56 obstructed men given salbutamol, obstruction reversed in 34% judged by FEV1 and 36% judged by airway resistance. Reversal occurred in 14 of 42 shipyard workers and 6 of 14 insulation workers, not a significant difference. This 34% was significantly higher than the 9% the authors earlier found in unexposed suburban COPD patients, and similar to the 36% in unexposed COPD patients exposed to city pollution. The authors concluded that asbestos-exposed workers had a high prevalence of reversible obstruction.

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: Retrospective study of lung-function records, compared with data from the authors' previously published study of COPD patients
• Who was studied: 97 men referred during the previous 2 years to a hospital lung-function laboratory in Marseille, France. 45 were shipyard workers, 12 built asbestos-cement elements and 40 installed home insulation. 59 had pleural plaques or thickening on chest x-ray (9 of them also had lung opacities), and 38 had normal x-rays. 60 of 97 were smokers. The comparison groups came from the authors' earlier study: 164 age-matched men with COPD and no occupational asbestos exposure (61 living downtown, 103 in outer suburbs).
• Exposure: Occupational asbestos exposure lasting 2 to 50 years, in shipyard work (boilermen and arc-welders), building asbestos-cement elements, or installing home insulation. Fiber types were not specified. Time since last exposure ranged from a few months to 38 years.
• Main results:
  • Lung volumes in the 97 workers did not differ significantly from predicted values.
  • Decreased FEV1 and FEV1/VC values were found in 63 of 97 workers (65%).
  • Airway resistance was increased in 46 of 86 workers (53%).
  • An isolated decrease in FEF25-75% (with normal FEV1) was found in 18% of the 97 workers.
  • Severe hypoxemia (low blood oxygen) was present in only 3 workers.
  • There was no significant difference in lung-function data between workers with and without x-ray abnormalities. The two groups did differ in other ways: time since last asbestos exposure was significantly shorter in those without pleural abnormalities.
  • In multiple regression, the only significant relationship was between FEV1 and age (slope = -0.214 plus or minus 0.108; r = .384; p less than .001).
  • No correlation was found between altered lung function and cigarette smoking, duration of asbestos exposure, or time since last exposure.
  • Among 56 workers with airway obstruction tested with inhaled salbutamol, reversible airway obstruction was found in 34% judged by FEV1 and in 36% judged by airway resistance.
  • Reversible obstruction was found in 14 of 42 (33%) shipyard workers exposed to both asbestos and industrial air pollution, and in 6 of 14 (43%) workers exposed to asbestos only (domestic heat insulation). The article does not state which reversibility measure these counts use.
  • The difference between these two worker subgroups was not statistically significant.
  • The 34% prevalence of reversible obstruction in asbestos-exposed workers was significantly higher (p less than .001) than the 9% previously measured in unexposed COPD patients living in outer suburbs.
  • The prevalence in asbestos-exposed workers was the same as the 36% previously measured in unexposed COPD patients exposed to outdoor air pollution.
• The authors' conclusion: The authors concluded that asbestos-exposed workers have a high prevalence of reversible airway obstruction, regardless of their specific occupational activities. They wrote that practitioners should check for it in workers using inhaled bronchodilators.

Topics

Medical terms in this study, explained in our Lexicon: Chest X-Ray, FEV1, Diffusing Capacity (DLCO), Habit, Asbestos Exposure, COPD.

Related studies

• Airway obstruction in asbestos-exposed shipyard workers: with and without irregular opacities — K.H. Kilburn, R.H. Warshaw (1990)
• Does asbestos exposure cause airway obstruction, in the absence of confirmed asbestosis? — J. Ameille, M. Letourneux, et al. (2010)
• Association between increased small airway obstruction and asbestos exposure in patients with asbestosis — X. Yang, Y. Yan, et al. (2018)
• Does asbestos exposure (asbestosis) cause (clinical) airway obstruction (small airway disease)? — A. Miller, W.N. Rom (2010)
• Airways obstruction among older construction and trade workers at Department of Energy nuclear sites — J.M. Dement, L. Welch, et al. (2010)
• Airway disease in non-smoking asbestos workers — K.H. Kilburn, R.H. Warshaw, et al. (1985)

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