Past Sources of I-131 in the Environment | Current Potential Sources of I-131 Exposure

Current Potential Sources of I-131 Exposure

Acute exposure to I-131 today could occur from unintentional or intentional releases.

Public exposure to or contamination of soil, food, or water by radioactive I-131 engenders intense fear. The emotional and psychological stresses resulting from exposure should be recognized and addressed early in a radiation incident.

The current main sources of I-131 exposure would be a localized hospital accident, a major nuclear power plant release involving melted fuel, or an aboveground atomic bomb detonation. The resulting iodine levels along the plume path would vanish over a period of a few days to months depending on dilution and radioactive decay.

Medical doses of I-131 resulting from medical procedures, including therapeutic thyroid ablations, release low levels of radiation in hospital nuclear medicine departments. Therapeutic thyroid ablations (mean thyroid dose of 10–100 Gy [1,000–10,000 rad]), are delivered primarily within 1 day and significantly exceed an entire year’s worth of background radiation. Patients undergoing this procedure release low levels of radiation for about 3 months. Unintentional releases from a medical facility at ambient temperatures should confine most of the I-131 to the facility and its surroundings.