Committee on Radiation Source Use and Replacement, National Research Council: “The U.S. government should take steps to promote the replacement of radioactive cesium chloride radiation sources, a potential “dirty bomb” ingredient used in some medical and research equipment, with lower-risk alternatives, says a new congressionally mandated report from the National Research Council. Cesium-137 in the form of radioactive cesium chloride in stainless steel capsules is used in self-contained irradiators at hospitals and universities for blood irradiation and in biomedical and radiation research, as well as other industrial uses. Approximately 1,300 radioactive high-activity cesium chloride devices, nearly all of them self-contained irradiators, are in use across the United States, and the number appears to be increasing. Replacements for radioactive cesium chloride and some other high-risk radioactive materials used in commercial devices are available, but they are more expensive, creating little incentive for users to switch.”