Hair taken from rats dosed with 203 Hg-labeled methylmercury was fed to previously untreated rats in order to determine if the organo-mercurial was available for release from the hair matrix within the gut lumen and for subsequent systematic absorption. Cumulative fecal excretion data were consistent with an absorption of about 80% of the ingested methylmercury. The relative amounts of methylmercury and of its metabolite, inorganic mercury, in the feces indicated that the percentage of the parent compound released from hair within the intestine equaled or exceeded the estimated bioavailability. Radioactivity in tissues of animals killed 42 hr following hair consumption confirmed that mercury absorption had occured.
