Transmigration of ingested asbestos.

There has been speculation that the ingestion of asbestos in food and drinking water may play some role in the etiology of cancer of the gastrointestinal (GI) tract. An important question in the evaluation of the possible human cancer risk associated with asbestos ingestion is whether fibers can penetrate into and through the GI tract in sufficient numbers to cause adverse systemic or local effects. Factors that complicate interpretation of the available data on the transmigration of ingested asbestos are discussed, and the preliminary results of our ongoing investigation of the penetration of amosite fibers into the normal and abnormal intestinal mucosa of the Wistar rat are reported.