Fate of ingested particulates (1980)

This 1980 EPA workshop paper reviewed published research on whether swallowed particles, especially asbestos fibers, pass through the digestive tract wall into the body. The authors judged that a 1974 report from three laboratories finding no penetration was not conclusive, citing contamination and low sensitivity. Reviewed studies reported asbestos in tissues of rats fed chrysotile and of a newborn baboon fed asbestos-containing formula. Another found amphibole fibers in tissues of 29 of 39 Duluth, Minnesota residents exposed through drinking water, against 2 of 21 control residents. Published passage estimates ranged from 1 fiber in 1,000 to 1 in 10,000. A rat study giving asbestos as a pellet gave 1 in 100,000, which the authors said may underestimate passage of fibers swallowed in water. From urine data on 4 people drinking Lake Superior water, the authors estimated as many as 1 in 200, assuming a steady state between fibers swallowed and fibers passed in urine. The authors concluded penetration was not on a large scale but could and did occur, and that many fibers were cleared through the urinary tract.

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.

From J-M's medical library

This copy comes from the Johns-Manville medical library. It was among the papers J-M kept in its medical library without an index entry.