Chrysotile asbestos in kidney cortex of chronically gavaged rats [Environmental hazards]

Using the transmission electron microscope, asbestos fibers have been assessed in kidney cortex of four groups of rats previously exposed to intermediate range feeding grade chrysotile asbestos. Newborn rats, from mothers gavaged with asbestos during pregnancy, were gavaged twice a week at the dose level of 50 mg/kg beginning at age day 7 until their natural death or sacrifice. Of the 20 rats comprising the four test groups, 17 were positive, average fibers recovery being 5.34 x 10 super(3)/mg dry weight. This study is consistent with the passage of chrysotile asbestos across the gastrointestinal wall.