Lactating cows were orally dosed with I,, CH31, NaI and NaIO, labeled with radioiodine. For these 4 chemical forms, the effective half-life in milk was approximately 1 day for the first 5 days. The peak thyroid concentration occurred approximately 2.8 days after ingestion in all the cows. Ion-exchange analysis indicated that, regardless of the chemical form administered, 97'3, of the iodine in the milk was inorganic. These results suggest that in dairy cows there are no significant differences in the thyroid uptake and milk transfer among the compounds tested.
A single oral dose of a tritiated luminous compound in common usage by the luminous dial painting industry was given to rats and cats, and the tritium concentration followed in the urine, feces and various body tissues. A major fraction of the absorbed tritium was eliminated with a biological half-life essentially the same as that of tritiated water.
In a previously published study it was reported that the eliminations of tritium from two human subjects followed a multi-component curve. Additional data have been collected on one of the subjects who exhibited a long half-life component of 2020 days which revise that estimate to 550 days. Another subject who received an industrial exposure was studied, and the results indicate a long half-life of 350 days for this subject. A possible seasonal variation in tritium excretion noted in the previous report was confirmed by the additionalRECENT study, the biological half-life of I -
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.