Asbestos content of omentum and mesentery in nonoccupationally exposed individuals

Our plain-English summary of Asbestos content of omentum and mesentery in nonoccupationally exposed individuals, by R.F. Dodson, M.F. O'Sullivan, D.R. Brooks, et al (Toxicology and Industrial Health, 2001).

The study

• Authors: R.F. Dodson, M.F. O'Sullivan, D.R. Brooks, J.R. Bruce
• Journal: Toxicology and Industrial Health
• Published: 2001;17(4):138-43
• Cited by: 20 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Asbestos fibers in occupationally exposed individuals relocate from the lung to extrapulmonary sites. A mechanism for relocation is via the lymphatic circulation. Indeed, asbestos fibers have been found in lymph nodes as well as pleural plaques. Our laboratory has recently shown that asbestos fibers also reach the mesentery and omentum in the peritoneal area where a small percentage of mesotheliomas occurs in exposed individuals. The present study uses light and analytical transmission electron microscopy for defining the asbestos burden in digested lung, omentum, and mesentery tissues from individuals considered as representing the general population in East Texas. The findings, when compared with previous data from occupationally exposed individuals, indicate extreme contrasts as to the level and types of fiber burden between individuals representing the groups.

In plain English

This laboratory study measured asbestos in tissue from 15 deceased people in East Texas whom the authors considered representative of the general population. There were 9 males and 6 females, aged 10 to 59, and none had a work history with documented asbestos exposure. Samples of lung, omentum and mesentery were dissolved and examined by light and electron microscopy. The omentum and mesentery are tissues in the abdomen, where peritoneal mesothelioma can arise. Ferruginous bodies were found in the lungs of 4 of the 15 people and in no omentum or mesentery sample. Single uncoated asbestos fibers were found in the lungs of 2 people, one chrysotile and one amosite. No asbestos fiber was found in any mesentery sample. Two omentum samples each held one fiber, chrysotile in one and tremolite in the other. All of these fibers except the lung chrysotile fiber were short. The authors concluded that lower lung burdens in the general population lead to only the rare short asbestos fiber in these abdominal tissues. They also concluded that the contrast with their earlier findings in occupationally exposed people with mesothelioma further establishes the link between inhaled asbestos and peritoneal mesothelioma.

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: Descriptive tissue fiber-burden study (lung, omentum and mesentery digests examined by light microscopy and analytical transmission electron microscopy), with comparison to the authors' earlier published data
• Who was studied: Discarded tissue from 15 deceased individuals considered representative of the general population in East Texas: 9 males and 6 females aged 10 to 59. Their listed occupations included homemakers, students, construction workers, a carpenter and a truck driver. Inclusion required no documented occupational asbestos exposure, no tissue changes suggesting asbestos disease, and a lung ferruginous body level consistent with this general population.
• Exposure: General-population (nonoccupational) exposure. There was no work history with documented asbestos exposure. Fiber types identified in tissue were chrysotile, amosite and tremolite asbestos.
• Main results:
  • Ferruginous bodies were found in lung digests from 4 of 15 individuals (cases 2, 7, 10 and 13).
  • No ferruginous bodies were found in any omentum or mesentery sample.
  • Uncoated asbestos fibers were found in the lungs of 2 of 15 individuals, one fiber each: amosite (case 4) and chrysotile (case 6).
  • No uncoated asbestos fibers were found in any mesentery sample. Two omentum samples each contained a single asbestos fiber.
  • The omentum fibers were chrysotile (case 5) and tremolite asbestos (case 8).
  • In the omentum, the single fibers corresponded to concentrations ranging from 145 fibers/g wet tissue to 176 fibers/g dry tissue.
  • For the two people with a lung asbestos fiber, the text gives concentrations from 1817 fibers/g wet tissue to 94,441 fibers/g dry tissue. However, the article's Tables 2 and 3 list the dry-weight lung values as 9441 (case 4) and 8385 (case 6).
  • Twelve of the 15 individuals had at least one uncoated nonasbestos fiber in their lung tissue. These included various magnesium and aluminum silicates.
  • The only asbestos fiber in any sample longer than 5 length units was a chrysotile fiber in the lung of case 6. The unit is printed as 'mm' in the scanned text.
  • In the authors' interpretation, the lower lung fiber burden in the general population results in only the rare occurrence of a short asbestos fiber in the omentum or mesentery.
• The authors' conclusion: The authors concluded that the sharp contrast in omentum and mesentery fiber burden compared with their earlier data from occupationally exposed people with mesothelioma further establishes the link of inhaled asbestos to the risk of peritoneal mesothelioma. They also concluded that chrysotile and noncommercial amphiboles are the main lung reservoirs available for transport to these sites in the general population.
• Limitations the authors state:
  • The authors noted that uncoated asbestos fiber levels in many individuals were below the detection limits of their counting scheme. This applied to 13 of 15 lung digests in the present study.

Topics

Medical terms in this study, explained in our Lexicon: Omentum, Mesentery, Pleural Plaques, Mesothelioma, Analytical Transmission Electron Microscopy (ATEM), Fiber Burden.

Related studies

• Asbestos in extrapulmonary sites: omentum and mesentery — R.F. Dodson, M.F. O'Sullivan, et al. (2000)
• Neoplastic and inflammatory processes of the peritoneum, omentum, and mesentery: diagnosis with CT — J.E. Hamrick-Turner, M.V. Chiechi, et al. (1992)
• Asbestos content in the lymph nodes of nonoccupationally exposed individuals — R.F. Dodson, J. Huang, et al. (2000)
• Tissue burden of asbestos in nonoccupationally exposed individuals from east Texas — R.F. Dodson, M.G. Williams, et al. (1999)
• Incidental mesonephric remnant hyperplasia of the jejunal mesentery: A diagnostic challenge — J.F. Val-Bernal, M.M. Mayorga, et al. (2021)
• Ultrastructure of mesothelial regeneration after intraperitoneal injection of asbestos fibres on rat omentum — S. Gonzalez, J. Friemann, et al. (1991)

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