Asbestosis in the industries of the Barcelona area

Our plain-English summary of Asbestosis in the industries of the Barcelona area, by F. Segarra, M.B. Monte, P.L. Ibañez, et al (American Journal of Industrial Medicine, 1980).

The study

• Authors: F. Segarra, M.B. Monte, P.L. Ibañez, A.G. Gonzalez, J.P. Nicolas
• Journal: American Journal of Industrial Medicine
• Published: 1980;1(2):149-58
• Cited by: 3 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. 002052).

Abstract

This presentation is the result of the survey of eight industries with asbestosis risk in the Barcelona area (two of fibro-cement, three of auto brakes, two of textiles, and one of insulation materials). Of 1,472 workers, 271 or 18.5% have asbestosis. Pleural involvement in asbestosis is twice as common as that of the lung, 15.7% versus 8.5%. Pulmonary asbestosis without pleural participation is seen in only 2.6% of cases. Pleural plaques, calcified and not calcified, are detected in only a few cases. There is a definite correlation between the incidence of asbestosis and the exposure time: from 1% in the group of workers with less than five years of exposure up to 64.58% for those with 30 or more years of exposure. Clinical symptoms (cough, and/or expectoration, and/or dyspnea) were present in 68% of the studied population. Pulmonary crepitations are the most significant physical sign detected, observed in one quarter to one third of the patients. Pulmonary function tests in asbestos workers revealed restrictive and mixed type syndromes in 17% of the cases and obstructive syndrome in 36%. The percentages for those workers without asbestosis are 9% and 16%, respectively. It seems, therefore, that a bronchial factor plays a role in asbestosis. The bronchial pathology would be manifested clinically by the appearance or the exaggeration of the chronic bronchitis symptoms, and physiologically by the presence of the obstructive syndrome. There is no doubt that smoking enhances the incidence of asbestosis, aggravates the respiratory symptoms in those affected, and is a cause of further deterioration of pulmonary function.

In plain English

This was a medical survey of 1,472 workers at eight asbestos-using factories in the Barcelona area: two fibro-cement, three auto-brake, two textile and one insulation-materials plant. It ran for nearly three years and ended in March 1978. The authors reported that chrysotile was the main fiber used in Spain, with small amounts of crocidolite and amosite in insulation materials. Asbestosis was diagnosed from work history and chest X-rays only. Of the 1,472 workers, 271 (18.5%) had asbestosis. Pleural involvement (15.7%) was about twice as common as lung involvement (8.5%). The share with asbestosis rose with years of employment, from 1% among those with under five years to 64.58% among those with 30 or more. Obstructive lung-function patterns were found in 36.16% of workers with asbestosis and 16.18% of those without. Asbestosis was found in 17.65% of smokers and 11.39% of non-smokers. The authors concluded that asbestosis involves the bronchi, and that smoking raises the chance of asbestosis and worsens symptoms and lung function. They noted that exposure doses could not be calculated and that symptoms were self-reported.

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 medical survey of workers in eight industries with asbestos exposure, using a questionnaire, physical examination, chest radiographs, lung function tests and laboratory tests
• Who was studied: 1,472 workers in the Barcelona area, Spain: 1,003 in fibro-cement manufacturing, 149 in textile industries, 301 in auto brake manufacturing and 19 in production of insulation materials. Mean age 38.56 years (range 15 to 69) and mean exposure 7.36 years. Survey ended March 1978.
• Exposure: Occupational asbestos dust in fibro-cement, auto brake, textile and insulation-material manufacture. Chrysotile was the most commonly used fiber, with very small amounts of crocidolite and amosite used in insulation materials. Measured mean dust concentrations for asbestos jobs were above the then-accepted limit of 2 fibers per cc, highest in textiles (mean values 3.11 to 22.52 fibers per cc) and lowest in fibro-cement (0.165 to 12.80 fibers per cc). Years of employment were treated as years of exposure.
• Main results:
  • Of all 1,472 workers examined, 271 (18.5%) had asbestosis on chest X-ray
  • Among all workers examined, pleural involvement was about twice as common as lung involvement: 15.7% versus 8.5%
  • Lung (pulmonary) asbestosis without pleural involvement was seen in only 2.6% of the workers
  • The share of workers with asbestosis rose with exposure time, from 1% in those with less than five years of exposure to 64.58% in those with 30 or more years
  • The authors described 15 years of exposure as a turning point: mean prevalence was about 8% before 15 years and 42% after
  • 997 of the 1,472 workers (67.73%) reported one or more respiratory symptoms (cough, expectoration, dyspnea). The figure was 78.23% in workers with asbestosis and 65.36% in those without, a difference reported as statistically significant.
  • Pulmonary crepitations were heard in 28.41% of workers with asbestosis and 4.66% of workers without asbestosis
  • 440 of 1,470 workers (30%) had abnormal pulmonary function tests
  • Obstructive syndrome was found in 36.16% of workers with asbestosis and 16.18% of those without. Restrictive syndrome was found in 8.86% and 3.67% respectively. These differences were reported as statistically significant.
  • Asbestosis was found in 161 of 912 smokers (17.65%) and 44 of 386 non-smokers (11.39%). Ex-smokers were left out of this comparison.
  • Pleural-only asbestosis occurred at about the same rate in smokers (8.99%) and non-smokers (8.54%)
  • Asbestos bodies were found in the sputum of 5% of workers, with no difference between those with and without asbestosis
• The authors' conclusion: The authors concluded that the symptoms and lung function results showed bronchial involvement in asbestosis. They also concluded that smoking increases the chance of acquiring asbestosis, aggravates respiratory symptoms in those affected and causes further deterioration of lung function.
• Limitations the authors state:
  • A dose-response relationship could not be accurately calculated. Workers had rotated between jobs, and only recent dust measurements were available, while past conditions were worse.
  • Asbestosis was diagnosed only from occupational history and X-ray findings. Symptoms, physical signs, lung function and laboratory data were not used in the diagnosis.
  • The authors said the high symptom rate may reflect several things: symptoms were subjective, they were collected by written questionnaire, and in the authors' view workers seeking compensation were prone to exaggerate.
  • Findings of crepitations vary with the examiner's skill and lack objectivity, which makes them risky to use for epidemiological purposes
  • The separate contributions of ordinary chronic bronchitis (common in city dwellers and smokers) and asbestos-related bronchitis could not be determined

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestosis, Pleural Plaques, Dyspnea, Pulmonary Function Test (PFT), Pathology.

Related studies

• Prospective study of asbestos-related diseases incidence cases in primary health care in an area of Barcelona province — M. Rosell-Murphy, R. Abós-Herràndiz, et al. (2010)
• Asbestosis in South African asbestos miners — G.K. Sluis-Cremer (1970)
• Pi*S and Pi*Z alpha 1 antitrypsin polymorphism and the risk for asbestosis in occupational exposure to asbestos — M.J. Lafuente, X. Casterad, et al. (2002)
• Asbestos lung burden and asbestosis after occupational and environmental exposure in an asbestos cement manufacturing area: a necropsy study — C. Magnani, F. Mollo, et al. (1998)
• Worker-sponsored survey for asbestosis: detection of occupational lung disease without a control group — D.H. Wegman, G.P. Theriault, et al. (1973)
• Prevalence of asbestos related lung disease among employees in non-asbestos industries — I. Young, S. West, et al. (1981)

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