Should a nuclear power plant emergency occur that involves a release of radiation, local and state officials may ask residents who live near the affected area to evacuate or shelter-in-place as a public safety measure. Potassium Iodide (KI) tablets may be taken as a supplemental protective measure in some situations.
Potassium iodide is not an "anti-radiation" pill. It is only a supplemental protective measure, secondary to evacuation or sheltering in place. Evacuation and sheltering in place remain the primary protective actions during a radiological emergency. Potassium iodide protects the thyroid gland against exposure to radioactive iodine in the unlikely event of a radiation release from a nuclear power plant emergency. If taken in an appropriate and timely dosage, potassium iodide can block exposure of the thyroid gland to radioactive iodine. However, potassium iodide does not protect other parts of the body from exposure to other contaminants released during the emergency.
Potassium iodide should only be taken after specific instruction by a state or local public health official.
Additional information is available on the California Emergency Management Agency's website at: www.oes.ca.gov.