Asbestos fibers: 1. A modified preparation of tissue samples for analysis by electron microscopy. 2. Presence of fibers in tissues of baboon fed chrysotile asbestos.

A specimen preparation technique is described which yields uniformly dispersed particles on transmission electron microscope (TEM) grids. It is relatively rapid and probably incurs no fiber loss. This technique was used to test the hypothesis that orally administered chrysotile asbestos may pass through the wall of the gastrointestinal tract (GI) of the neonate baboon. A test neonate baboon was bottle-fed chrysotile asbestos which was suspended in a milk formula. Control and test baboons were sacrificed at the end of a 9-day feeding period, and several tissues were removed and preserved. Kidney, liver, and spleen tissues were prepared for TEM analysis. Tissues from the control animal showed no fibers. The number of chrysotile fibers recovered from the test kidney cortex was significantly higher than the level found in the control kidney cortex (p less than 0.005). The frequency distribution of fibers lengths in the kidney cortex was very similar to that of the feeding suspension. This study suggests that a wide range of fiber sizes can penetrate the GI tract and migrate.