Ammonium iron hexacyanoferrate in veterinary medicine and the Chernobyl disaster: an ion exchanger for radiocesium

Abstract The Chernobyl nuclear disaster of April 1986 released significant radioactive contamination by means of radionuclides across Europe, presenting unprecedented challenges to environmental, radiochemistry, human and veterinary medicine. Among the most effective countermeasures developed was ammonium iron hexacyanoferrate, a Prussian blue compound that efficiently binds radiocesium in the digestive tract of animals. This compound prevented the absorption and bioaccumulation of dangerous radionuclides such as cesium-134 and cesium-137, significantly reducing contamination in the food chain. In German-speaking countries and Scandinavia, this compound became known as Giese salt after Werner Giese, the veterinarian and physicist who pioneered its application after Chernobyl. This article examines the chemistry of this remarkable compound and its classification among Prussian blue compounds, the role of radiocesium in the ecosystem, food safety and agricultural countermeasures, the history and applications of Giese salt in veterinary medicine such as powder, lickstones, and granulates, and its vital role in mitigating one of the worst nuclear disasters in history.