Asbestos risk among full-time workers in an electricity-generating power station

Our plain-English summary of Asbestos risk among full-time workers in an electricity-generating power station, by A. Hirsch, L. Di Menza, A. Carre, et al (Annals of the New York Academy of Sciences, 1979).

The study

• Authors: A. Hirsch, L. Di Menza, A. Carre, A. Harf, S. Perdrizet, J. Cooreman, J. Bignon
• Journal: Annals of the New York Academy of Sciences
• Published: 1979;330:137-45
• Cited by: 9 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. 004032).

Abstract

A matched survey of 55 full-time workers probably exposed to asbestos in an electricity-generating power station (exposed group) and of 53 unexposed workers in an automobile plant has been conducted. The asbestos risk in the power station was confirmed by the presence of airborne fibers in the range 0.1--6000 X 10(-9) g/m3 in the air sampled during the survey period and by the presence of FB in the sputa of 32.7% of the workers. The following parameters were significantly related to asbestos exposure in the study group: FB in the sputa, localized rectitude of the diaphragm, pleural thickening, pleural calcification, and the chest pain. Moreover, for all persons studied, gastrointestinal symptoms and recent hoarsening of the voice were significantly related to the number of FB in the sputa.

In plain English

This French study compared 55 full-time staff of an electricity-generating power station, parts of which had asbestos insulation, with 53 men from a nearby car factory whom the authors called unexposed, though three recalled earlier light asbestos exposure. Workers were examined in 1977 with a questionnaire, chest x-rays, breathing tests and sputum tests; air was sampled in both plants. Ferruginous bodies, which the authors link to the intensity of asbestos exposure, were found in the sputum of 18 power-station workers (32.7%) and three factory workers (5.6%). The authors reported that chest pain was significantly more frequent in the power-station group. They also reported three pleural x-ray changes as linked to exposure: localized straightening of the diaphragm, pleural thickening more than 5 mm thick, and pleural calcification. Lung-tissue shadows did not differ significantly between groups. Average breathing capacity was lower in the exposed group. Four cases of asbestosis were declared for compensation. The authors concluded that full-time power-station staff, not only insulation workers, faced an asbestos risk. They noted that past airborne asbestos levels had not been measured.

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: Survey comparing an exposed group with an unexposed control group; the authors call it a matched survey and an etiologic retrospective study
• Who was studied: 55 male volunteers from the full-time staff of an electricity-generating power station (EDF, Vitry, France), with an average of 24.2 years of employment and a minimum of 3 years. The control group was 53 men from an automobile factory in the same area (Renault, Choisy le Roi), described in the methods as having no previous asbestos exposure; however, three of them recalled earlier light exposure. All were examined June 6 to November 7, 1977.
• Exposure: Asbestos-containing insulation (lagging) in high-temperature areas of the power station. Air samples were taken inside and outside workplaces in both plants and analysed by electron microscopy. They found chrysotile and amphibole fibers in the power station and virtually none in the automobile factory.
• Main results:
  • Ferruginous bodies were found in the sputum of 18 of the 55 exposed workers (32.7%) and 3 of the 53 control workers (5.6%).
  • Among exposed workers with ferruginous bodies, counts ranged from 1 to 282, with a mean of 24. The three positive controls had 1 to 2 each, and all three recalled earlier light asbestos exposure before working at the automobile factory.
  • Respiratory symptoms were equally frequent in both groups, except chest pain, which was significantly more frequent in the exposed group.
  • Three pleural abnormalities were significantly more frequent in the exposed group than in controls: localized rectitude of the diaphragm, pleural thickening more than 5 mm thick, and pleural calcification.
  • Parenchymal (lung tissue) opacities on x-ray did not differ significantly between the two groups.
  • Mean FVC was 96% of predicted in the exposed group and 103% in controls (p = 0.03). Mean MEFR 25%/FVC was 87% of predicted in the exposed group and 106% in controls (p = 0.05). The numbers of workers in each abnormal test category did not differ significantly between the groups.
  • Across both groups, the frequency of some abnormalities possibly related to asbestos was correlated with the number of ferruginous bodies in sputum.
  • Four cases of asbestosis were declared to the French Social Security system for compensation.
  • One exposed worker was diagnosed with bronchogenic carcinoma 6 months after the study ended. This worker had no ferruginous bodies in sputum.
  • Air sampling found virtually no asbestos fibers in the automobile factory.
• The authors' conclusion: The authors concluded that the sputum findings confirm an asbestos risk for the full-time staff of an electricity-generating power plant, and that this risk was not limited to workers doing lagging.
• Limitations the authors state:
  • There were no measurements of airborne asbestos in the workplaces over the whole working period.
  • Respiratory questionnaires are difficult to use, and the data must be interpreted cautiously.
  • In the newer building, no air sample had been taken during insulating operations.
  • The authors said the two laryngeal cancers among other power-station workers must be interpreted with caution because the population was selected.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis, Power plants and utilities.

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Diaphragm, Pleural Thickening, Pleural Calcification.

Related studies

• Occupational respiratory cancer and exposure to asbestos: a case-control study in a cohort of workers in the electricity and gas industry — E. Imbernon, M. Goldberg, et al. (1995)
• Mortality of UK electricity generation and transmission workers, 1973-2002 — L. Nichols, T. Sorahan (2005)
• Malignant mesothelioma in thermoelectric power plant workers in Italy — P. Crosignani, F. Forastiere, et al. (1995)
• Asbestos related health hazards among power plant workers — Y. Lerman, A. Finkelstein, et al. (1990)
• Mortality among workers in the geothermal power plants at Larderello, Italy — E. Pira, M. Turbiglio, et al. (1999)
• Extrapulmonary neoplasms among asbestos-exposed power plant workers — I.G. Ron, H. Ron, et al. (1999)

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