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.
Hydraulic fracturing and radionuclides
As radon decays, it produces radioactive decay products. If the contaminated dust of these "radon daughters" are inhaled, they can lodge in the lungs and increase the risk of developing lung cancer. Iodine in food is absorbed by the body and preferentially concentrated in the thyroid where it is needed for the functioning of that gland. When Iodine-131 is present in high levels in the environment from hydraulic fracturing flowback and blowouts, it can be absorbed through contaminated food and water, and will also accumulate in the thyroid. As it decays, it may cause damage to the thyroid. The primary risk from exposure to high levels of iodine-131 is the chance occurrence of radiogenic thyroid cancer in later life. Other risks include the possibility of non-cancerous growths and thyroiditis. The level of radiation in hydraulic fracturing wastewater has been measured to be as high as 18,035 pCi/L, thousands of times the maximum allowed by the federal standard for drinking water, and there are concerns about radiation exposure during spills and blowouts. Long term exposure to low level radiation is associated with stochastic health effects; the greater the exposure, the more likely the health effects are to occur. A group of doctors from the United States have called for a moratorium on hydraulic fracturing until health effects are more thoroughly studied.