Unethical human experimentation in the United States
In 1953, the AEC ran several studies at the University of Iowa on the health effects of radioactive iodine in newborns and pregnant women. In one study, researchers gave pregnant women from of iodine-131, in order to study the women's aborted embryos in an attempt to discover at what stage, and to what extent, radioactive iodine crosses the placental barrier. In another study, they gave 25 newborn babies (who were under 36 hours old and weighed from ) iodine-131, either by oral administration or through an injection, so that they could measure the amount of iodine in their thyroid glands, as iodine would go to that gland.
Isotopes of iodine
All other iodine radioisotopes have half-lives less than 60 days, and four of these are used as tracers and therapeutic agents in medicine. These are I, I, I, and I. All industrial production of radioactive iodine isotopes involves these four useful radionuclides.