How is radiation poisoning treated?
Potassium iodide can be used to block radioactive iodine from being taken into the thyroid gland, protecting it from injury. It cannot protect other parts of the body, or reverse damage to the thyroid once it has occurred. Prussian blue, a dye used by artists and manufacturers since 1704, can also be used to remove certain radioactive materials from the body.
Potassium Iodide as a Thyroid Blocking Agent in Radiation Emergencies
Questions and Answers on Prussian Blue
Meltdown alert at Japan reactor
NHK World English
"The Great Wave off Kanagawa" by Hokusai, a famous artwork which makes extensive use of Prussian blue.