Iodine in terrestrial wildlife on the U.S. department of energy's Hanford Site in southcentral Washington

Iodine-129 in controlled amounts has been released into the air from the operating chemical separations facilities on the Hanford Site. Small amounts of ¹²⁹I have accumulated in surface soils especially at locations near the chemical separations facilities. Enriched levels of ¹²⁹I also occur in the thyroid glands of mule deer (Odocoileus hemionus) residing on the Hanford Site.Stable iodine is present in low concentrations in Hanford Site soils and it is not avidly accumulated by wild plants. Soils at high elevations have greater concentrations of ¹²⁷I than low elevations soils. Mule deer thyroids had higher concentrations of stable iodine than the thyroids of black-tailed jackrabbits. Stable iodine in black-tailed jackrabbit thyroids varied with the season with maximal concentrations in summer.Iodine-131 has not been released into the air from operating chemical separations facilities for more than 10 yr. Because of its short half-life ¹³¹I of Hanford Site origin has disappeared from the Hanford Site. In the event of a future restart of the chemical separations facilities black-tailed jackrabbits can be used as biological indicators of ¹³¹I in the terrestrial environment of the Hanford Site.