Radiographic And Functional Changes Following Exposure To Different Types Of Asbestos

Our plain-English summary of Radiographic And Functional Changes Following Exposure To Different Types Of Asbestos, by F. Sulotto, C. Romano, A. Berra, et al (1980).

The study

• Authors: F. Sulotto, C. Romano, A. Berra, W. Arossa, S. Spinaci
• Published: Biological Effects Of Mineral Fibres (J.C. Wagner, Editor), Lyon: Iarc Scientific Publications, Volume 30, Pp. 565-569 (1980)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library, J-M no. 002186. The article is still under copyright, so we describe it here rather than post it.

In plain English

This study, by researchers in Turin, Italy, examined lung function and chest X-rays in 200 asbestos workers (129 men, 71 women) during 1977 and 1978. All were claiming compensation. Based on investigations at their firms, 138 workers had been exposed to both chrysotile and crocidolite and 62 to chrysotile only. Exposure lasted about 12 years on average. Only 17.5% had normal lung function. The most common abnormal pattern was one the authors attributed to small airways disease. After adjusting for age, height, sex and smoking, workers exposed to chrysotile alone had less severe impairment than those also exposed to crocidolite. For example, the table gives average vital capacity as 4,310 versus 3,980 litres, with commas standing for decimal points. Lung function did not vary significantly with duration of exposure or with rough exposure indices. Smokers had lower values on several tests. No X-ray feature was significantly more common in crocidolite-exposed workers, but the authors reported that X-ray abnormalities were related to length of exposure. The authors noted that crocidolite-exposed workers mainly worked in textiles, and that suitable dust measurements were lacking.

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 study of lung function tests and chest X-rays in asbestos workers claiming compensation
• Who was studied: 200 asbestos workers (129 males, 71 females), mean age 46.85 years (range 23-69), examined in 1977 and 1978 by the Institute of Occupational Medicine, University of Turin, Italy. 103 were smokers. All were claiming compensation. Jobs included miners, millers, brake and clutch workers, asbestos-cement workers, textile workers and insulation workers.
• Exposure: Exposure to chrysotile only (62 workers, 40 smokers) or to both chrysotile and crocidolite (138 workers, 63 smokers), determined from investigations in the firms. Duration ranged from 1 to 51 years. Dust exposure was estimated only with rough job-based indices scored 1, 3 or 5.
• Main results:
  • Normal lung function was found in 17.5% of the 200 workers.
  • A pattern the authors attributed to small airways disease was seen in 67 smokers and 57 nonsmokers.
  • Restrictive impairment was seen in 10 smokers and 14 nonsmokers. Obstructive impairment was seen in 9% (12 smokers and 6 nonsmokers).
  • Lung function did not vary significantly with duration of exposure.
  • Lung function indices were not related to exposure indices, or to exposure indices multiplied by duration of exposure.
  • Workers exposed to chrysotile only had less severe impairment than those exposed to both chrysotile and crocidolite.
  • Mean vital capacity, adjusted for age, height, sex and smoking, is printed as 4,310 litres in workers without crocidolite exposure versus 3,980 litres in crocidolite-exposed workers (P 0.001). The commas stand for decimal points.
  • Mean FEV1 (forced expiratory volume in one second), adjusted, is printed as 3,380 litres without crocidolite exposure versus 3,120 litres with it (P 0.001). The commas stand for decimal points.
  • Mean total lung capacity, adjusted, is printed as 5,498 litres without crocidolite exposure versus 5,224 litres with it (P 0.025). The commas stand for decimal points.
  • Smokers as a whole had significantly lower FEV1 (P less than 0.0025), MEF25 (P less than 0.025) and MEF50 (P less than 0.05) than nonsmokers. The difference remained after adjusting for crocidolite exposure.
  • No chest X-ray feature was significantly more frequent in crocidolite-exposed workers.
  • The authors reported that X-ray abnormalities were related to length of exposure. Elsewhere, they reported no difference in the type and profusion of lung shadows among the four exposure-duration groups.
• The authors' conclusion: The authors concluded that, in a population with moderate asbestos exposure, lung function tests can distinguish smokers from nonsmokers and exposure to different kinds of asbestos. They concluded that differences between groups with different lengths of exposure are better seen on X-rays. They attributed the obstructive impairment in the sample to cigarette smoking, which did not affect the difference between workers with and without crocidolite exposure.
• Limitations the authors state:
  • The lack of a relationship between lung function and duration of exposure could be due to confounding by age.
  • The authors did not obtain suitable dust exposure values; exposure was evaluated only with rough indices.
  • Crocidolite-exposed workers mainly worked in the textile industry, where fiberizing itself produces thinner, more penetrating fibres. Fiber type and job therefore overlap.

Topics

Medical terms in this study, explained in our Lexicon: Chest X-Ray, Chrysotile, Crocidolite, Standing.

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