Analyses of tissue, blood, and urine samples from a baboon gavaged with chrysotile and crocidolite asbestos

Our plain-English summary of Analyses of tissue, blood, and urine samples from a baboon gavaged with chrysotile and crocidolite asbestos, by W.H. Hallenbeck, D.R. Markey, D.G. Dolan (Environmental Research, 1981).

The study

• Authors: W.H. Hallenbeck, D.R. Markey, D.G. Dolan
• Journal: Environmental Research
• Published: 1981;25(2):349-60
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Tissue, blood, and urine samples from one test and one control baboon were analyzed by transmission electron microscopy for the presence of chrysotile and crocidolite asbestos. The test animal had been gavaged with cumulative doses of 800 mg each of chrysotile and crocidolite asbestos. Urine and blood samples were collected during the 15-day gavage and 21-day postgavage period. Twenty-two tissues were collected at sacrifice. None of the analyses of tissue, blood, or urine samples from the test animal exceeded the expected level of background contamination for chrysotile. One crocidolite bundle was observed in a test sample. The results of this study indicate that asbestos fibers do not penetrate the gastrointestinal tract of the baboon and migrate to various tissues.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This animal experiment tested whether swallowed asbestos passes through a baboon's gut wall into other tissues. It also checked earlier baboon results from the same laboratory. One female baboon received 100 mg each of chrysotile and crocidolite by stomach tube on 8 days within a 16-day period. That totalled 101 mg per kg of body weight of each fiber type. A second female baboon received filtered water only. Urine and blood were collected repeatedly; 22 tissues were taken at sacrifice on day 37. All samples were examined by transmission electron microscopy. Initial analyses of four test tissues and two test blood samples showed elevated chrysotile counts, but repeat analyses indicated these were most likely contamination; no reported chrysotile count exceeded its expected background level. One crocidolite bundle was seen in a kidney cortex preparation from the test animal, but this could not be reproduced. The authors concluded that, given the study's limitations, the results do not support the hypothesis that ingested asbestos penetrates the baboon gastrointestinal tract and migrates to tissues. They noted insensitive detection limits and only one test animal.

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: Animal experiment (feeding by stomach tube) with one test and one control baboon. Its aim was to improve on, and check, earlier baboon studies from the same laboratory.
• Who was studied: Two healthy female baboons (Papio anubis). The test animal was 38 months old and weighed 7.9 kg. The control animal was 40 months old and weighed 6.3 kg. Urine and blood were collected during the 16-day gavage period and the 21-day postgavage period. Twenty-two tissues were collected at sacrifice on day 37. Location and dates are not stated.
• Exposure: The test animal received 100 mg of chrysotile plus 100 mg of crocidolite in water by stomach tube on 8 days, roughly every second day, over a 16-day period. Cumulative doses were 800 mg of each type, or 101 mg/kg body weight of each. The control animal received 50 ml of filtered water by stomach tube on each gavage day.
• Main results:
  • No chrysotile fiber counts above the expected background contamination level were seen in any reported urine, blood or tissue preparation. For this reason the counts were not converted to fibers per ml or per mg.
  • First analyses showed elevated, clustered chrysotile counts in several samples: four test tissues (jejunum, urinary bladder, peritoneum and omentum), two test bloods, one control blood and one control urine. Re-preparation and reanalysis indicated these counts were most likely due to unusually high background contamination, so they were not reported.
  • One crocidolite bundle was seen on a kidney cortex preparation from the test animal. It was not found again on a second tissue preparation or on reanalysis of the original preparation.
  • No crocidolite fibers were seen in the urine or blood samples.
  • At sacrifice, no signs of irritation were seen in the esophagus or stomach of either baboon.
• The authors' conclusion: The authors concluded that, given the study's limitations, the low fiber counts do not support the hypothesis that ingested asbestos fibers can penetrate the baboon gastrointestinal tract and migrate to various tissues.
• Limitations the authors state:
  • The detection limits were relatively insensitive: 440 fibers/ml of urine, 4.4 x 10^4 fibers/ml of blood, and 220 fibers/mg of dry tissue. Penetration and migration may therefore have gone undetected.
  • Only one test animal was used. Individual differences between baboons might allow penetration and migration in some members of the species but not others.
  • More frequent sampling of blood and urine might have detected fibers.
  • Fibers with different length and diameter distributions from those given might result in penetration and migration.

Topics

Medical terms in this study, explained in our Lexicon: Chrysotile, Crocidolite, Transmission Electron Microscopy (TEM), Cumulative Dose.

Related studies

• Presence of fibers in the urine of a baboon gavaged with chrysotile asbestos — W.H. Hallenbeck, K.J. Patel-Mandlik (1979)
• A comparison of the effects of exposure of baboons to crocidolite and fibrous-glass dusts — B. Goldstein, R.E. Rendall, et al. (1983)
• Characterization of asbestos fibers in lungs and mesotheliomatous tissues of baboons following long-term inhalation — K. Hiroshima, Y. Murai, et al. (1993)
• New insights into the toxicity of mineral fibres: A combined in situ synchrotron μ-XRD and HR-TEM study of chrysotile, crocidolite, and erionite fibres found in the tissues of Sprague-Dawley rats — A.F. Gualtieri, N. Bursi Gandolfi, et al. (2017)
• Ingested mineral fibers: elimination in human urine — P.M. Cook, G.F. Olson (1979)
• Use of quantitative analysis of urine to assess exposure to asbestos fibers in drinking water in the Puget Sound region — E.S. Boatman, T. Merrill, et al. (1983)

Browse more research in Environmental Research, or return to medical research.