Asbestos fibers in human pulmonary and extrapulmonary tissues

Our plain-English summary of Asbestos fibers in human pulmonary and extrapulmonary tissues, by J. Huang, N. Hisanaga, K. Sakai, et al (American Journal of Industrial Medicine, 1988).

The study

• Authors: J. Huang, N. Hisanaga, K. Sakai, M. Iwata, Y. Ono, E. Shibata, Y. Takeuchi
• Journal: American Journal of Industrial Medicine
• Published: 1988;14(3):331-9
• Type of article: Case report
• Cited by: 30 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. 000231).

Abstract

The association between asbestos fibers in human lung tissues and those in other extrapulmonary organs was studied by analysing three autopsied cases, one of whom had a high pulmonary asbestos burden, one an intermediate burden, and one a low burden. The amount, types and sizes of asbestos fibers in the tissues of lung, liver, spleen, pancreas, kidney, and gastrointestinal tract were identified and measured by transmission electron microscopy equipped with an energy dispersive X-ray analyser. The following results were obtained: 1) The concentrations of asbestos fibers in extrapulmonary organs tended to increase with that in lung tissues. 2) The types of fibers identified in lungs were approximately consistent with those in other organs. 3) A relatively large range of fiber length was observed in both lungs and other organs. The findings extend and support previous light microscopic studies comparing asbestos bodies in various organs, and may imply that persons with high levels of asbestos in their lungs are also likely to have the same types and high levels of asbestos in their other tissues.

In plain English

This study used transmission electron microscopy with X-ray analysis to compare asbestos fibers in the lungs and other organs of three men autopsied at two hospitals in Aichi Prefecture, Japan. Case 1 had worked in thermal insulation for 37 years and had asbestosis. Case 2 had worked in a foundry for 37 years, and asbestos exposure was possible but not definite. Case 3, a salesman, had no evidence of asbestos exposure. Lung fiber levels were highest in case 1, then case 2, then case 3. Levels in the kidney, liver, spleen, pancreas and gastrointestinal tract followed the same order. In case 3, fibers were found only in lung, stomach, colon and rectum. In case 1, amosite made up 93.6% of fibers in the lung and 80% or more in other organs. In case 2, only anthophyllite, tremolite and actinolite were found. Fiber lengths did not differ significantly between lungs and other organs in cases 1 and 2. The authors suggested that people with high lung asbestos levels are likely to have the same fiber types and high levels elsewhere. They added that definite conclusions cannot be drawn from three cases.

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: Autopsy tissue analysis of three cases (case series) using transmission electron microscopy with energy dispersive X-ray analysis
• Who was studied: Three men, aged 67, 70 and 73 at death, from two hospitals in Aichi Prefecture, Japan. Their lung samples had been selected to represent high, intermediate and low lung asbestos levels. Liver, spleen, pancreas, kidney and gastrointestinal tract tissue from autopsy was also analysed.
• Exposure: Case 1: thermal insulation work for 37 years, with asbestosis, lung cancer and pleural plaques. Case 2: casting work in a foundry for 37 years, where talc was used as a parting powder; occupational asbestos exposure possible but not definite. Case 3: salesman of cosmetics and food, with no evidence of asbestos exposure.
• Main results:
  • Lung asbestos concentrations were 157.81 to 247.81 million fibers per gram of dry tissue in case 1, 53.80 to 88.63 million in case 2, and 1.07 to 2.11 million in case 3. This put the cases in the order case 1, then case 2, then case 3.
  • Asbestos was detected in all tissues examined in cases 1 and 2. In case 3, only trace amounts (0.04 to 2.11 million fibers per gram of dry tissue) were detected, in lung, stomach, colon and rectum.
  • Fiber levels in kidney, liver, spleen, pancreas and gastrointestinal tract paralleled those in the lungs, in the order case 1, then case 2, then case 3.
  • In case 1, the kidney had the highest concentration among the organs outside the lung (12.50 million fibers per gram of dry tissue). In case 2, the stomach had the highest (3.82 million fibers per gram of dry tissue).
  • In case 1, amosite accounted for 93.6% of asbestos fibers in the lung and 80% or more in the other organs.
  • In case 2, only anthophyllite, tremolite and actinolite were identified, in both lungs and other organs. In case 3, only ten fibers were detected: amosite (1), tremolite (2) and anthophyllite (7).
  • In cases 1 and 2, fiber length did not differ significantly between lungs and other tissues (Kruskal-Wallis test, p greater than 0.1). Fiber lengths varied widely in all tissues.
  • Four blank samples, examined over 45 grid openings to check for laboratory contamination, contained a total of two amosite fibers (0.04 fiber per grid opening).
• The authors' conclusion: The authors suggested, as a possibility, that persons with high levels of asbestos in their lungs are also likely to have the same types and high levels of asbestos in other body sites. They noted that the study did not examine any local cancer-causing effect of fibers outside the lungs.
• Limitations the authors state:
  • Definite conclusions cannot be drawn from only three cases; more cases and more tissues need to be analysed.
  • The authors could not determine whether the different kidney fiber levels in cases 1 and 2 were due to the different fiber types in the two cases.

Topics

Medical terms in this study, explained in our Lexicon: Transmission Electron Microscopy (TEM), Fiber Length, Asbestos Bodies.

Related studies

• An assessment of asbestos body formation in extrapulmonary sites: liver and spleen — M.G. Williams, R.F. Dodson, et al. (2001)
• Strain differences in pleural mesothelial cell reactions induced by potassium octatitanate fibers (TISMO) infused directly into the thoracic cavity — M. Yokohira, Y. Nakano, et al. (2013)
• The dose-dependent effects of ingested chrysotile on DNA synthesis in the gastrointestinal tract, liver, and pancreas of the rat — D.E. Amacher, A. Alarif, et al. (1975)
• Formation of the nitrative DNA lesion 8-nitroguanine is associated with asbestos contents in human lung tissues: a pilot study — Y. Hiraku, K. Sakai, et al. (2014)
• Letter: Penetration of asbestos through the digestive tract of rats — R.D. Pontefract, H.M. Cunningham (1973)
• The association among ferruginous body, uncoated fibers, asbestos and non-asbestos fibers in lung tissue in terms of length — T. Suzuki, Y. Sakakibara, et al. (2016)

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