Ingestion of asbestos

Our plain-English summary of Ingestion of asbestos, by S.H. Zaidi (Environmental Health Perspectives, 1974).

The study

• Author: S.H. Zaidi
• Journal: Environmental Health Perspectives
• Published: 1974;9:239-40
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 002371).

In plain English

This was a short commentary, published in 1974, on papers given at a conference, not a research study. It reported no new data on asbestos. The author, from the Industrial Toxicology Research Center in Lucknow, India, discussed which animals should be used to study swallowed asbestos. The author argued against rats, because half of the rat's stomach is lined with a different tissue than the human stomach. The author also argued against monkeys, whose stomachs always contain leftover food. The author described earlier rabbit and dog experiments that did not involve asbestos, and favored dogs and guinea pigs for future work. The author suggested that the stomach's protective mucous layer may help stop asbestos particles from penetrating. The author offered this as a possible reason why monkeys in another conference paper had no particles attached to the stomach lining. As speculation, the author suggested that people with a weak mucous barrier who swallow asbestos may develop stomach or intestinal tumors. The author concluded that fiber movement through the gut should be studied in relation to this mucous barrier.

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: Commentary (opinion piece published in 1974 discussing papers presented at a conference); not a research study and reports no new asbestos data
• Who was studied: No study population. The commentary is by an author at the Industrial Toxicology Research Center, Lucknow, India. It discusses the choice of experimental animals (rats, monkeys, rabbits, dogs, guinea pigs) for asbestos ingestion research.
• Exposure: Ingestion (swallowing) of asbestos in general; no fiber type, product or dose is specified
• Main results:
  • Author's opinion: rats are unsuitable for ingestion studies because half of the rat's stomach is lined by squamous epithelium and so does not resemble the human stomach
  • Author's opinion: monkeys should not be used for stomach or intestine studies because, as vegetarians, they always have food particles and roughage in the stomach
  • Author's recollection of earlier rabbit experiments, which did not involve asbestos: rabbits fasted for 4 days still had stomach food present at sacrifice. Gastric analysis showed high free acidity of the duodenal ulcer type.
  • Author's opinion: dogs would be preferred because the dog stomach is very similar to the human stomach for experimental ulceration. The author recalled producing gastric and duodenal ulcers in dogs with cinchophen, which did not involve asbestos.
  • Author's opinion: the guinea pig is another suitable choice because it is inexpensive and easy to handle
  • Author's suggestion: the stomach's mucous barrier may be one of the most important factors that may stop asbestos particles from penetrating. Roughage-induced mucus may explain why monkeys in another conference paper (Webster) did not have particles attached to the stomach mucosa.
  • Author's speculation, not a finding: people with a deficient mucous barrier who ingest asbestos particles may develop tumors of the intestine or stomach
• The authors' conclusion: The author concluded that the movement of asbestos fibers in the gastrointestinal tract should be studied in relation to the mucous barrier

Related studies

• Light and electron microscope studies of the rat digestive tract following prolonged and short-term ingestion of chrysotile asbestos — R. Jacobs, J. Humphrys, et al. (1978)
• Rapporteur's Report Session 5: assessment of health risk associated with exposure to non-asbestiform amphiboles including ingestion studies — B. Price (2008)
• A preliminary study of biochemical changes in the rat small intestine following long-term ingestion of chrysotile asbestos — R. Jacobs, K.S. Dodgson, et al. (1977)
• Distribution of 6-6(n)-3[H]sucrose and its radiolabeled degradation products from isolated, perfused rat small intestine loops following prolonged ingestion of chrysotile asbestos — R. Jacobs, R.J. Richards (1980)
• The ingestion of asbestos fibers — I. Webster (1974)
• The use of animal models for studies on asbestos bioeffects — J.M. Davis (1979)

Browse more research in Environmental Health Perspectives, or return to medical research.