Asbestos in the sputum, crackles in the lungs, and radiologic changes in women exposed to asbestos

Our plain-English summary of Asbestos in the sputum, crackles in the lungs, and radiologic changes in women exposed to asbestos, by J.C. Davies, D. Kielkowski, J.I. Phillips, et al (International Journal of Occupational and Environmental Health, 2004).

The study

• Authors: J.C. Davies, D. Kielkowski, J.I. Phillips, M. Govuzela, A. Solomon, M.R. Makofane, M.L. Sekgobela, E. Garton
• Journal: International Journal of Occupational and Environmental Health
• Published: 2004;10(2):220-5
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

In a rural community in South Africa historically exposed to asbestos environmentally and occupationally, 200 women who had worked with asbestos and applied for medical examination to determine compensable asbestos disease were evaluated. Clinical and radiologic evaluation, sputum collection, and microscopic analysis were done. A questionnaire elicited type of exposure, duration, decade of first work exposure, and environmental exposure. Crackles were present in the lungs of 166 women and asbestos fibers and ferruginous bodies were present in 122. Asbestosis was identified in 26 and plural plaques in 62. Auscultation for crackles (rales) is useful in the initial examination of former asbestos workers in rural communities of developing countries.

In plain English

This study examined 200 women who had worked in amphibole asbestos mines in the Pietersburg asbestos field of South Africa. All had applied for compensation examinations at Mecklenburg Hospital from May 2000. Each woman answered a questionnaire and had a chest X-ray and a chest examination for crackles. 199 gave sputum (175 gave two samples, 24 one), which was checked for asbestos fibers and ferruginous (asbestos) bodies. Crackles were heard in 166 women (83%). Of 195 women with satisfactory sputum, the text reports fibers in 162 and asbestos bodies in 33. Sputum findings did not predict crackles or X-ray changes. On X-ray, 13% had parenchymal fibrosis and 31% had pleural changes. X-ray changes were associated with decade of first employment and time since first exposure, but not with how long the women worked. Crackles were associated with exposure, parenchymal changes and pleural calcification. The authors concluded that crackles are a sensitive and reliable clinical sign of asbestos-related parenchymal fibrosis and pleural calcification. They noted that the women were survivors, so severe disease was likely underrepresented, and that employment recall may have been biased.

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 clinical, radiologic and sputum study of women attending compensation examinations (the article does not give a formal design label)
• Who was studied: 200 women, former asbestos workers from a rural community in the Pietersburg asbestos field (Limpopo/Northern Province, South Africa), who applied for benefit (compensation) examinations at Mecklenburg Hospital from 1 May 2000. 72% were aged 50 or older and 28% were over 70.
• Exposure: Occupational work in amphibole asbestos mines and mills, mainly cobbing (65.5% with or without other tasks; 52.5% cobbers only), plus sorting, sweeping and other tasks. First employment was before 1939 (4%), 1939 to 1959 (48%), or 1960 and after (48%). 44.5% worked under 5 years, 38.5% worked 5 to 9 years, and 17% worked longer. 46% were born into households where adult relatives worked in asbestos mines.
• Main results:
  • Crackles were heard in 166 of the 200 women (83%). They were bilateral in 159 of these 166.
  • Sputum was obtained from 199 of the 200 women: 175 gave two specimens and 24 gave one.
  • Among the 195 women with satisfactory sputum specimens, the text reports that 162 had asbestos fibers and 33 had asbestos bodies.
  • Ferruginous bodies were found in sputum up to 58 years after last exposure, and fibers up to 60 years after.
  • Sputum findings were not associated with the exposure measures and did not predict crackles or radiologic changes. Crackles were not associated with fibers or ferruginous bodies in sputum.
  • On X-ray, 13% of the women had parenchymal fibrosis, 31% had pleural changes, and 36% had either or both.
  • Parenchymal fibrosis, pleural changes and any radiologic asbestos-related disease were associated with decade of first employment but not with duration of employment. The association between parenchymal fibrosis and residence time did not reach statistical significance.
  • Crackles were significantly more common among women first employed in earlier decades and among those employed longer. By decade of first employment, crackles were present in 8 of 8 women first employed before 1939, 86 of 96 first employed 1939 to 1959, and 72 of 96 first employed 1960 and after. Crackles were also associated with parenchymal changes and pleural calcification on X-ray.
  • Radiologic evidence of tuberculosis was found in 20 women (10%), but only five women (2.5%) said they had been treated for tuberculosis.
• The authors' conclusion: The authors concluded that fibers and ferruginous bodies in sputum are markers of exposure. They found that radiographic changes correlated with decade of first employment and residence time but not duration of employment, and that crackles are a sensitive and reliable clinical sign of asbestos-related parenchymal fibrosis and pleural calcification.
• Limitations the authors state:
  • The women were a survivor group in a rural area with many competing causes of death, so those with extensive disease were underrepresented.
  • Low literacy and recall of remote events may have introduced recall bias, including in the stated durations of employment.
  • No dust measurements exist before 1949, so there is no exposure information for women first exposed before 1939. Decade of first employment was used as a stand-in for exposure intensity.
  • The ILO reference radiographs for grading pneumoconiosis are standardized for men, and there is no comparable set for women.

Topics

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

Medical terms in this study, explained in our Lexicon: Sputum, Environmental Exposure, Ferruginous Bodies.

Related studies

• Sputum asbestos bodies and radiographic changes in residents of Wittenoom, Western Australia — A.W. Musk, J.E. Baker, et al. (1983)
• Correlation between respiratory symptoms and pulmonary function in asbestos-exposed workers — C.A. Brodkin, S. Barnhart, et al. (1993)
• Crackles in the early detection of asbestosis — R.L. Murphy, E.A. Gaensler, et al. (1984)
• Lung crackle characteristics in patients with asbestosis, asbestos-related pleural disease and left ventricular failure using a time-expanded waveform analysis--a comparative study — N. al Jarad, S.W. Davies, et al. (1994)
• Asbestos bodies in the sputum of asbestos workers: correlation with occupational exposure — C. Paris, F. Galateau-Salle, et al. (2002)
• A method for extracting ferruginous bodies from sputum and pulmonary tissue — M.J. Smith, B. Naylor (1972)

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