Potassium iodide floods the thyroid with stable iodine so that radioactive iodine inhaled or ingested afterwards is mostly excreted instead of absorbed. It works best when taken shortly before or within a few hours of exposure and protects only the thyroid, not the rest of the body. Authorities pre-distribute tablets near nuclear plants and advise when to take them; the protective action is called iodine thyroid blocking.
Public health just authorized KI for the 2-mile ring, push the message through the alert system.
KI is not a radiation pill: it does nothing for external dose or for caesium, and taking it late gives little benefit.
Also heard as
- potassium iodide
- iodine tablets
Related terms
EPZ
Emergency planning zone: the area around a nuclear plant where protective actions are pre-planned.
Sheltering
A protective action in which people stay indoors with doors and windows shut to reduce dose from a passing plume.
Plume
The cloud of radioactive gases and particles carried downwind from a release.
Source term
The amount, type, timing and chemical form of radioactive material released, or assumed released, in an accident.